Rehabilitation of oiled African Penguins:

a conservation success story

Edited by

Deon C. Nel and Phil A. Whittington

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Rehabilitation of oiled African Penguins:a conservation success story

Edited by

Deon C. Nell and Phil A. Whittington2

l BirdLife lnternational Seabird Conservation Programme, BirdLife South Africa,PO Box 1586, Stellenbosch, 7599, South Africa;

2Avian Demography lJnit, Department of Statistical Sciences,University of Cape Town, Rondebosch, 7701, South Africa

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BirdLife South Africa and the Avian Demography Unit, Cape Town

2003

)ABirdLifeSOUTH AFRICA

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Published by Birdl-if'e South Africa and the Avian Demography Unit, Cape Town, South Afi1ca

Birdlife South AfricaPO Box 1586

Stellcnbosch1 599South Africa

Telephone: (02 I ) 886-9222Fax: (021) 886-9223E-mail : infb @birdlile.org.zaWebsitcs: Bi.rtlLifeSA - www.birdlife.or:g.za; Seobird Progrtunnte - www.savethealbatross.org.za

Avirrrr Dernogrirphl UrritUniversity o1 Cape TownRondebosch71otSouth Africa

Telephone: (021) 650-2123Fax: (021) 650-3,134E-mail : adu @ adu.uct.ac.zaWebsite : www.avi andemographyunit.org

First published 2003

O Birdlife South Africii and the Avian Demography Unit 2003

Cover plates:Front: Released rehabilitated penguins returning to sea following the Treasure oi1 spill, Woodbridge Island, Cape TownSeptember 2000. Photo: A.P. van Dalsen.Back: Contrasting fortunes: oiled and unoiled African Penguins at Dassen Island. Photo: A.C. Wolfaardt.

Line illustration:Title page: African (Jackass) Penguin by L. McMahon, taken from Harrison, J.A., Allan, D.G., Underhill, L.G., Herremans,

M., Tree, A.J., Parker, V. & Brown, C.J. 1991 . The atlas of southern African birds, vol. 1. Birdlife South Africa, Johannes-

burg.

Photographs: C. Loch-Davis, J.L. Nel, S. Petersen, H. Ratz, L. Upfold, A.P. van Dalsen, P.A. Whittington, A.C. Wolfaardt

Digital image editing: R.A. Navarro

DTP: F.A. Stoch

Printing and binding: Fotoplate and Mills Litho Book Printers, PO Box 4503, 8000, Cape Town, South Africa

Alt rights reserved. No part of this book may be reproduced, stored in a

retrieval system, or transmitted in any form or by any means, electronic,mechanical, photocopying or otherwise, without the permission of the pub-lisher.

ISBN: 0-620-30012-4

Foreword

The south-western coasts of South Africa are a global hotspot for oil pollution. This is not due tounusual local negligence but is caused by structural failure of foreign vessels in passage between theAtlantic and Indian oceans. Other than pollution of shores, the prime result of these spillages is theoiling of the endemic African Penguin Spheniscus demersws.

The first sighting of an oiled African Penguin was as early as the 1920s (Kearton 1930)1 but oilingonly became a severe threat after the Arab-Israeli conflicts closed the Suez Canal to tanker traffic.This led to the re-routing, around Africa, of tankers taking oil from the Arabian Gulf to Europe. Gen-erally the tankers kept well offshore, but as they rounded South Africa the vessels came close to thecoast to reduce transpoft costs and pick up fresh supplies. Small enough to pass through the canal,and previously sailing largely in the enclosed Red and Mediterranean seas, these vessels were un-suited to the rougher fully oceanic conditions off South Africa's coast. The result was a series oftanker wreckings and oil spillages. To reduce the costs of crewing large numbers of small tankers,new super-tankers were developed. These reduced the number of tankers, but significantly increasedthe potential magnitude of oil spills if these tankers were damaged.

A series of spills on the South African coast in the late 1960s led Mrs Althea Westphal to estab-lish SANCCOB (the Southern African National Foundation for the Conservation of Coastal Birds).Initially based on Mrs Westphal's backyard swimming pool, SANCCOB grew to become an organi-sation with its own dedicated cleaning station and, aI its peak, a banked reserve worth several mil-lion US Dollars. This volunteer organisation, though caring for any sick, injured, or polluted seabirds,was dedicated largely to the de-oiling of penguins. During its first 20 years SANCCOB handled some9,000 penguins as well as smaller numbers of other seabirds. In the 1980s there were few large spillsand SANCCOB ran at a very amateur level.

The sinking of the Apollo Sea in June 1994 heralded a phase of renewed penguin oiling, largelythe result of fuel oils spilt due to inadequate maintenance of cargo vessels. The 10,000 penguins oiledin the Apollo Sea splll led to radical improvements in SANCCOB, notably more professional birdtreatment. This culminated in the Treasure spill of June 2000 in which some 20,000 penguins wereoiled, captured, de-oiled and released whilst an additional 19,000 non-oiled penguins were caught,and relocated 800 km away. This enabled them to feed for themselves whilst travelling back to theAtlantic over a two-week period during which the spill dispersed and beach cleaning was undertaken.Handling oiled penguins in this spill was an international effort but made possible by havingSANCCOB's facilities, expertise and volunteer support upon which to build.

The five papers in this booklet assess the present situation in the light of these spills. Les Underhillstresses the fortunate resilience of the African Penguin which, seemingly far better than any otherbird, is able to cope with the stresses of oiling as well as the multiple handling during de-oiling. DeonNel, Rob Crawford and Nola Parsons review the conservation status of the African Penguin and theimpact oiling is having on this species. Phil Whittington presents results, from his doctorate, whichevaluate the post-release survival of de-oiled penguins. Anton Wolfaardt and Deon Nel report on thesubsequent breeding productivity and annual cycle of de-oiled penguins. Their report is based on astudy initiated, immediately after the Apollo Sea spill, in order to assess whether de-oiling was worththe cost and effort in terms of penguin future reproductive contributions. Peter Ryan estimates thedemographic impacts that de-oiling has had upon African Penguins and indicates that, as a resultlargely of SANCCOB's efforts, the populati on is lg%o larger now than if there had been no de-oiling.

Readers are urged to consider these documents in the light of wider contexts. First the impact ofoil pollution upon African Penguins must be considered against this species' significant populationdectease, reduced from some 1.5 million adults in 1900 to about 150,000 in2002. Oiling is not theprime cause of this decrease. Penguins have suffered from massive habitat disruption through removalof fossil guano caps at breeding islands in the mid-1840s. Subsequently there was major commer-

cial over-exploitation of penguin eggs. Since the late 1940s penguins have had to compete for food

- mainly shoaling sardines and anchovies - within penguin swimming range (c.20 km) of breed-

ing islands against the less constrained commercial purse-seine fishery and also against Cape FurSeals Arctocephalus pusillus.In addition, these seals, whose population has risen from some 100,000

in 1900 to over two million in200l, displace penguins from some breeding localities, and may be

substantial predators of the penguins themselves.The other contextual situation for these papers is that faced by SANCCOB, the prime organisa-

tion responsible for the rescue and de-oiling of African Penguins. When SANCCOB was initiatedthe exchange rate between the South African Rand and the US Dollar was nezr parity and affluentSouth Africans had more disposable income for the suppoft of NGOs. The exchange rate is now nine

Rands (and has been as high as 13) to the Dollar, and disposable income has fallen radically.SANCCOB's financial reserves have been depleted severely through depreciation, during a period

when provision of adequate care for penguins has risen markedly in cost. The result is that an in-creasingly cash-strapped NGO is having to react to oiling resulting from intemational trade between

more affluent nations. The South African government, at its several levels, is prepared to assist

SANCCOB in terms of manpower and logistical support during significant spills (involving oilingof 500+ penguins). However, the government lacks funds to divert to penguin cleaning when so

many of its people remain trapped in poverty exacerbated by the AIDS epidemic. These factors have

forced SANCCOB to adopt a more business-like structure. In the short term, this has led to a loss

of penguin treatment expertise without significant gain in income. It is difficult to see how in the

medium (5-year) term SANCCOB can continue to provide a high level of service to the AfricanPenguin without substantial funding (in Rand terms) from the international community. Its value

in terms of helping to preserue this Vulnerable species is amply demonstrated by the results presented

in this book.

Tony (A.J.) WilliamsAvian Scientist

Western Cape Nature Conservation Board( SAN C C O B Executiv e C ommitte e member I 994-200 I )

Kerrrttrrr. C. l9l0 Tlt,'isl,trrcl tl ltetrqrrins. Longmrns. London. )22 pp.

Dedication

To Althea Westphal, whose vision and determination saved thousands of seabirds, and to Charl vander Merwe, who loved penguins and whose generosity made this publication possible.

Acknowledgements

The publication of this booklet was made possible by means of a donation by the Charl van derMerwe Foundation to Birdlife South Africa.

The digital images were edited by Ren6 Navarro and desktop publishing was done by FeliciaStoch, both of the Avian Demography Unit.

The rescue of African Penguins is facilitated by staff of Western Cape Nature Conservation Board,South African National Parks, Marine and Coastal Management, the Avian Demography Unit,Robben Island Museum and SANCCOB, as well as numerous volunteers. Substantial input at rescueand rehabilitation centres has been provided by the International Bird Rescue and Research Centre,New England Aquarium, Philip Island Nature Park, Royal Society for the Protection of Birds,Birdlife South Africa, the Wild Bird Federation of Taiwan, Tri-State Bird Rescue and Research Inc.,The World Wide Fund for Nature (WWF), The Green Trust and the International Fund for AnimalWelfare.

About the authors

Deon Nel is the Scientific Coordinator for Birdlife International's Seabird Conservation Pro-gramme. Following the Apollo Sea oil spill, Deon spent 18 months on Dassen Island studying thereintegration of rehabilitated African penguins into their wild population. Since then he completedhis doctorate on "The effects of longline fishing on the seabirds breeding on Marion Island". Deonalso holds a MSc in Conservation Biology from the FitzPatrick Institute, University of Cape Town.

Phil Whittington completed his doctorate on "Survival and movements of African Penguins,especially after oiling" at the Avian Demography Unit at the University of Cape Town. He spentten years as an ornithologist with the British Trust for Ornithology before embarking on a periodof travel that eventually led him to South Africa and his doctoral research. Phil holds a BSc (Hons)degree from the University of London.

Rob Crawford is a Principal Specialist Scientist in the Directorate of Marine and Coastal Manage-ment, South Africa. He has conducted research into southern Africa's seabirds over the past 20 years,including annual monitoring of the breeding populations of all South African seabird species. Robis a past chairman of SANCCOB's executive committee.

Nola Parsons is the Bird Rehabilitation Manager at the SANCCOB rescue centre. She is a qual-ified veterinarian from the University of Pretoria and has been working at SANCCOB for the pasttwo years. She is cumently registered for an MSc degree at the University of Cape Town, studyingthe breeding productivity of African Black Oystercatchers at Koeberg Nature Reserve.

Anton Wolfaardt is a Regional Ecologist for the Western Cape Nature Conservation Board. Anton'sexperience with seabird research and conservation began on Marion Island, where he conducted fieldstudies of various sub-Antarctic seabirds. He then spent two years studying rehabilitated penguinsfrom the Apollo Sea oil spill and a further three years as the Reserve Manager for Dassen Island.Anton is cumently working towards his doctorate on "The impact of oiling and rehabilitation on thebreeding biology of African Penguins" at the Avian Demography Unit, University of Cape Town.

Peter Ryan is a Senior Lecturer in the Percy FitzPatrick Institute for African Ornithology, Universityof Cape Town, where he coordinates the MSc programme in Conservation Biology. He has a long-standing interest in seabird conservation, dating back to his MSc research on the impacts of plasticingestion on seabirds, conducted during the mid-1980s. Peter has worked intermittently on AfricanPenguins since his undergraduate days and has advised conservation agencies on management ofpenguin-human interactions at Boulders and Dassen Island.

Les Underhill is the Director of the Avian Demography Unit at the University of Cape Town, andserves on the board of SANCCOB. Seabirds and shorebirds form a major research areafor the AvianDemography Unit and Les has supervised numerous MSc and doctoral research projects on theeffects of oil on seabird populations.

Contents

Executive summary .................. viii

The conservation status and impact of oiling on the African Penguin

Deon C. Nel, Robert J.M. Crawford & Nola Parsons .......................... 1

Post-release survival of rehabilitated African Penguins

Phil A. Whittington ....................8

Breeding productivity and annual cycle of rehabilitated African Penguinsfollowing oiling

Anton C. Wolfaardt & Deon C. Nel ............18

Estimating the demographic benefits of rehabilitating oiled African Penguins

Peter G. Ryan.......... .................25

Are African Penguins tough enough? A perspective on the rehabilitation ofoiled birds

Les G. Underhill... ....................30

Plates

Rescue and transport................ .................... 11

Stabilisation and c1eaning................. ...........I2

Rehabilitation and release .......13

Reintegration and follow-up research .........14

Executive summary

The African Penguin Spheniscus demersus population has decreased greatly over the last century.The population at the start of the 21st century is about l)Vo of what it was at the start of the 20thcentury and is largely confined to two areas, both located close to major shipping ports.

The first documented oil spill affecting African Penguins occurred in 1948 and since then morethan 47,000 penguins have been admitted to the Southerl African Foundation for the Conservationof Coastal Birds (SANCCOB). However, there has been a dramatic increase in the number of birdsoiled since 1990. This is largely due to two catastrophic oil spills that oiled more than 30,000 birds:the Apollo Sea spill in 1994 and the Treasure spill in 2000. At present more than 80Vo of oiled birdsthat are admitted to SANCCOB are cleaned, rehabilitated and released back into the wild in a healthycondition. The cost of rehabilitating a penguin in a catastrophic oil spill is less than US$ 100, makingthis the most cost*effective rehabilitation centre for seabirds worldwide.

After their release from the centre, rehabilitated African Penguins appear to survive just as wellas unaffected birds. At least 87Va of rehabilitated African Penguins return to their breeding coloniesand post-rehabilitation annual survival rates are no different from those ofunaffected penguins. Someof the oldest known surviving African Penguins are birds that had been rehabilitated at SANCCOB.Furthermore, at least 60Vo of rehabilitated birds that were resighted at their colonies have been re-corded breeding. Overall, breeding success of rehabilitated birds was no different from unaffectedbirds although during times of extreme food shortages rehabilitated birds appeared to fare less wellthan unaffected birds.

Initial disruptions to the annual breeding and moulting cycles and established pair-bonds wererecorded immediately after a catastrophic oil spill. The relocation of clean penguins as a proactivemeasure for avoiding oiling was shown to be a great success. The proportion of birds recorded breed-ing was higher for translocated birds, compared to oiled-rehabilitated birds, indicating that this pro-cess was far less disruptive to their breeding cycles. A simple deterministic model shows that therehabilitation of oiled African Penguins has resulted in the present population being l9%o larger thanit would have been in the absence of cleaning. This excludes the contribution made by translocatingclean birds to avoid oiling.

The future cost of ceasing to rehabilitate oiled penguins ranges from 17-51 Vo of the populationafter 20 yea.rs, as the probability of a major spill increases from 5-207o per year. Although the demo-graphic impacts of cleaning oiled penguins were initially modest, this activity is becoming increas-ingly important for conserving African Penguins. Penguins are impressively tough animals, a qualitythat enables them to be cleaned when they become oiled. However, in order to be successful, thecleaning operation has to be mobilised rapidly. For this reason, SANCCOB needs to be maintainedin a state ofreadiness for action continuously.

viii

The conservation status and impact of oiling on the African Penguin

DEoN C. NELl, RoBERT J.M. CFIAWFoRD2 & NoLA PARSoNS3

l BirdLife lnternational Seabird Conservation Programme, BirdLife South Africa,PO Box 1586, Stellenbosch, 7599, South Africa, e-mail: dnel@savethealbatross.org.za;

2Marine and Coastal Management, Private Bag X2, Rogge Bay, 8012, South Africa;ssouth African National Foundation for the Conseruation of Coastal Birds,

PO Box 11116, Blouberg, 7443, South Africa

Abstract

Nel, D.C., Crawford, R.J.M. & Parsons, N. 2003. The conservation status and impact of oiling on the AfricanPenguin. In: Nel, D.C. & Whittington, P.A. (eds), Rehabilitation of oiled African Penguins: a conseryationsuccess story. BirdLife South Africa and the Avian Demography Unit, Cape Town, South Africa. pp. l*7.

The African Penguin Spheniscus demersus population is at present abotrt lOTo of what it was at the beginningof the 20th century. Currently more than 807o of the global population breeds in two confined areas. The heartof these areas both lie within 50 km of a major shipping harbour and adjacent to the Cape shipping route,making the population extremely vulnerable to oiling. The first recorded oiling of African Penguins occur:redin 1948 and the South African Foundation for the Conservation of Coastal Birds (SANCCOB) was establishedin 1968followingthegroundingof the EssoEssen. Sincethenmorethan 41 ,}}OoiledAfricanPenguinshavebeen admitted to SANCCOB. However, there has been a dramatic increase in the numbers of birds oiled duringthe last decade (1991-2000). This was mainly due to two catastrophic oi1 spills. In 1994, a bulk ore carrier,the Apollo Sea, sank near Dassen Island, oiling 10,000 penguins. Four years later, almost 20,000 oiled pen-guins were rescued when another bulk ore carrier, rhe Treasure, sank close to Robben Island. The incidenceof oiling from smaller slicks of unknown origin has also increased during the last decade. However, effortsto rescue, clean and rehabilitate oiled African Penguins have been highly successful and have continued toimprove over the last three decades. Currently more than 807o of oiled African Penguins that are admitted toSANCCOB are released back into the wild in a healthy state. The cost of rehabilitating African Penguins duringa catastrophic event such as the Treasure oil spill is less than US$ 100 per bird released back into the wild ina healthy state, making this by far the most cost-effective seabird rehabilitation effort in the world. However,these successes rely heavily on the SANCCOB rehabilitation facility and expertise being maintained in a stateof readiness between oil spills.

Conservation status

The African Penguin Spheniscus demersus is the only penguinspecies that breeds in Africa. Breeding is restricted to southernAfrica from Algoa Bay on the south-east coast of South Africato central Namibia on the west coast of Africa (Figure 1), al-though non-breeding birds regularly disperse as far as KwaZulu-Natal and southem Angola. African Penguins curently breedat 27 colonies, having disappeared as a breeding species at 10Iocalitiesl. However, 77Vo of the population currently breed onjust four islands. Furthermore, more thanS)Vo of the populationbreed in just two small and distinct geographic areas (with aradius of <50 km). More than 40Vo of African Penguins breedon the islands between Saldanha Bay and Cape Town, withalmost another 4}Tobreeding within Algoa Bay near Port Eliza-beth (Figure 1).

The present population is about lOTo of that at the start of the20th century when it was estimated at over 1.45 million adultbirds2 (Figure 2). In the 1950s the poputation had declined to300,000 adults and by the late 1970s ro only 220,000. By thelate 1980s, the population was down to 194,000 adults and inthe early 1990s only 179,000 adults remainedl. Given the large

decrease in the 20th century, there is considerable concem aboutthe long-term viability of the African Penguin in the wild. It islisted as Vulnerable in the South African Red Data Book forbirds3, is considered Vulnerable in terms of the IUCN threat-ened species categoriesa, and is listed in Appendix II ofboth theConvention on Trade in Endangered Species (CITES) and theBonn Convention for the conservation of migratory speciess.

The initial decline in numbers of African Penguins wasdriven by direct exploitation by humans. An average of almost500,000 eggs were removed annually from Dassen Island alonebetween 1900 and 19306. Furthermore, massive disturbance andhabitat alteration were caused by the collection of guano dur-ing this period 7. More recently, reduced availabitity of pelagicfish prey, resulting from competition with commercial fisher-ies, has been responsible for the ongoing declines8. Through theyears, other factors have included mortality in oil spillse, com-petition for space on breeding islands with the burgeoningpopulation ofCape Fur Seals Arctocephalus pusillus 10, preda-tion11 and entanglement in fishing gear and other marine litterT.

It is clear that the African Penguin has experienced a torridtime in the 20th century, resulting in a severely reduced popu-lation with an insecure future. As populations of wild animals

Nel & Whittington (eds): Rehabilitation of oiled African Penguins

Figure 1. Extant breeding colonies of African Penguins. Reproduced with permission from the Directorate of Marine and CoastalManagemeni, South Africa.

Nel ef a/.: Conservation status and impact of oiling on the African penguin

decrease in size they bccorne more vulncLltble to stochasticevents that carr triggel further dcclines. The vr-rlnerability ofAll'ican Pengr-rins is increased l'r-u'thel by its concentration withinrelatively srnall eeographic areas. Consecluently. catastrophicevents, in the fbrrn o1'large-scnle oil spills atfbcting thous:rnclsol birds. have now becorne one of the most impor-tant irnmedi-ate thrcats llrcing Alrican Penguins. Tl.re species' vulnerabilityto oiling is further greatly cxacerbatcd by the tact that rnore tharr80% of the population breed within just t 00 knr of a major sl.rip-

Pin-q l.rarbour.

The impact of oiling on African Penguins

The earliest known incident in which African Penguins wer.eaffected by oiling was the grouncling of the Ei,so Wlteeling nettrDycl Island in 194816. Another major oil spill on Robben Islandin 1953 al'f'ected 1.200 penguinslT. However. oil pollution in-cidents prior to 1967 were poorly docunrented arrd their ettecton seabiril populations were not assessed.

The first attempts to clean oiled penguins were reportecl inl963lE. Atternpts to rehabilitate oilecl seabirds on a l:u-{c scalefbllowed the groundinu of the Es.io E,s"icrr off Cape point in1968 when about 1.700 oiled penguins were collectedle. Sub-secluently .100 cleaned penguins were released. The E.i,ro Es.ienincident led to the establishment of the South Afiican NationalFoundation firr the Conselvarion rlf Coastal Birds (SANCCOB)in November l968lo.

Between I 970 ancl 2000 thcre have been at least 1zl nrajoroiling incidents that have threaterled lar-ue nurnbers of AfricanPenguins (Tab1e l). lt is interesting to note that the incidentsinvolving the largest aurourlts ofoit did not necessiu.ily havc thegreatest impact on the penguins (Table l). The two incidentsresultirr-u in the most peneuins being oiled (.the Apol.lo Scn andthe Treosure) involved re lativelv small arnounts of tuel oil fl-om

bulk ore carriers, whereas the inciclent involving the largcstarnount ol'oil, the sinking ol'the tanker Custi.llo cle Bellver. didnot oil any penguins. The location o1'the spill and prevailingweather conc'litions are far mote important than the actualamount oloil that is spilt. Although the Castillo de Bellver sanklelatively close to ntajol penguin colonies, fbrtunateiy a strongsor:th-easterly wind rnoved the oil fur.ther- olfshorcll. Both theApollo Sea ancl Trea.strre. on the other hand, sank close to largepenguin colonies during typical Cape wintcr stonls. with pre-vailing north-westerly winds causing the oil to renrain closcinshcx'e and/or drilt onto the landing beacl'rcs of nrrLjor penguilbreeding colonies on Robben and Dassen Islands. The r-rn-

seasonally calm weather that fbllowed inrmediltely after thesinking of the TretLstLre allowed oil to ren'rain even longer in-shore, causir-rg rnaxirnum clamage.

Nine of the ele.n,en maior oiling incidents involving mor-ethan 500 penguins occurred between March and Ar-rgust. Howcver, it is not onlv the nrajcil oil spills that occur predon'rinantlyduring thc winter rnontl.rs. Srnaller oiling incidents of unknownoligin, presurnably resulting from vessels illcgally rvashing outtheir bilges, also occur more fiequently during the wintcrmonths in the Western Cape. This is pr-esumably also dr-re topredorninant onshore north-westerly winds rnoving oil slickscloser inshore :rnc'l within the fbraging range of penguins breecl-ing at major colonies.

lncidence of oiling

A total of abor-rt 47,0(X) oiled Afl'ican Penguins havc been ad-mitted to SANCCOB over fol past three decades, .rt an avera.qeof abor-rt I .500 birds per yetr'. The incidence of oiling has varieclgreatiy ovel this tinre and 7'7a/r, ol birds have heen oilecl betweenl99l and 2000 (Fi-uure 3). Prirtr to t990 n'rost oiled penguinsaclmittecl to SANCCOB werc trom incidents of unknown orisin.

The biology of

Feeding ecology

African Penguins forage mostly during the day, feed:ing on pelagicshoaling fish such as anchovies and pilchards. Although dives ofup to 130 m have been lecorded, most prey are captured in theupper 30 m of the water co1umn12. Most birds are found within20 km of the coast13 and their distribution matches that of pelagicshoal fish, which typically occur within the 200 m depth contourla.Adult penguins typically forage in groups, working together toconcenlrate schools ol fish. g, .on',rrriron. jur eniles tend to lbr-age singly, preying on more sluggish fish prey.

Moulting?As with a1l pengr.rins, African Penguins replace all their feathersat once during an annual rnoult. Old. worn f-eathers have to be re-placed by new f'eathers to ntaintain fhe bird's insulation and swim-ming speed; o1d f-eathers have greater drag. Dr-rring the moult birdsare landbound at tlreir breeding islands for about 2l days and haveto rely on fat reserr.es built Lrp during a five-week pre-moult period(which is spent at sea, overnighting at the feeding grounds). By thetime a bird returns to sea afier the moult. it has lost almost half ofits weight when it canre ashore. After the moult, the pengLliusspend an uninterupted period of about six weeks at sea, to recovertiom the rnoult fast.

BreedingT' Afier returning to tlreir breecling colonies fbllowing the post-rnoultL-

African Penguins

feeding period, breeding birds take ownership of their nesting sites.African Penguins show high fidelity to their mates and their nest-ing site. Many pairs have bred together tbr ten years or more at thesame site. A two-egg clutch is laid about three weeks after return-ing, and incubation lasts about ,tl days. Both members of a pairparticipate equally in incubation, with one bird feeding at sea whileits mate is incubating. At hatching the chicks are helpless and can-not be left alone owing to their inadequate thermoregulatory abil-itjes and their vulnerability to predation by Kelp Gulls larzstl.ominicanus. At about 15 days they have <ievelopecl the ability tothermoregulate, but they remain vulnelable to predation until about30 days old. Parents share I'eeding and guarding duties e<1ua1ly.

Chicks fledge at an average weight of about 2.6 kg and it nonnallytakes about 90 days and 26 kg offish to raise a chick to this stage!Parents feed chicks right up to the day of their departure from theirbreeding islands, when they will enter one of the most criticalphases of their 1ives.

JuvenilesJuvenile penguins stay away from their natal colonies for longperiods, spending much of this tirne at sea. Only about 32Vo willsurvive their first year at sea7. Over the years they will begin tospend more time at their natal colonies, until they reach sexualmatudty. Most birds breed for the first time between the ages olthree and live yearsl-5, and only abolt2lc/o of juvenile birds willreach this age7.

Nel & Whittington (eds): Rehabilitation of oiled African Penguins

1,S00,000

1,400,000

1,200,000

1,000,000

800,000

600,000

400,000

200,000

1900 1910 1920 1930 1940 19s0 1960 1970 1980 1S90 2000

Figure 2. Changes in the population size of African Penguins 1900-2000. The graph is superimposed on a picture of the former huge

colony on Dassen lsland taken in the early 1900s. Estimates of the size of this colony have ranged to as high as nine million; however, itis now generally accepted that at least 1.4 million birds bred here in 19102.

0

Horvever. sincc 1990. '18% of all oilecl penguins u ere victirnso1'.jLrst two catastlophic oil spills. The sinking ol-the Apollo Sect

in 1994 rcsultecl in apploximatclv 10.000 penguir.rs bcing oiled.Foul years later, the greatest single oiling disaster event struckthe African Penguin popttlation when the bulk carrier Trea.sure

sank close inshorc and just north of Robben [slar.rd. Approxi-mately 20,000 oilecl penguins (.121/r, of the global population)were rescued anc'l transported trl lehabilitation centres in thedays that fbllowecl.

Even in the absence of thcse two catastrophic oil spills, itappears that the incidence of oiling h:rs increased during the last

decade. Between 1990 and 1999, an average of 925 penguins(0.5Vo of the global population) were admitted annually toSANCCOB from incidents other than the Apollo Sea and theTreasure spills. This is far greater than the annual average of343 between 1980-1989 and 547 between 1970 arrd 1979. Al-though very large catastrophic oiling events are the most impor-tant immediate threat to the population, smaller spills and oilslicks of unknown origin (presumably due to ships illegallywashing their bilges) are also increasing and constantly chip-ping away at the population.

Table 1. Some of the major oil spills along the southern African coast, 1968-2000. Taken from Whittington (2002) and references therein2T

Name of vessel/incident

Type of incident Locality Year Oil spilt(tonnes) and type

Number ofpenguins oiled

Ess,:t Essen (tirnker)

KtLzitttcr h.

'|4/ay'r:i (tanker)

UnknownOsw-ego Guortlittn/

Tercmilct (tankers)

Orienttl Pirtneer

Ve npetNenoil(tar.rkers)

Pcmtelis A. Lentos

Castillo cle BelLver(tankcr:)

Kqtodi.str.ius(bulk carrior)

Apollo Sect

(bulk ore carrier)

UnknownCordiglieruCape Torvn Harbour

spill

Trettstt re(bulk orc carrier)

Struck submergecl

ob.ject

Ran agrouncl

Ran agrouncl

t-Inknou,u

CollidedRiur aground

ColliclcdRan aground

Blokc up lncl sank

Ran agrouncl

Sank

ChronicBroke rpalt

Burst pipcline

Sank

Clapc Poirrt

Robben Island

Capc AguJhas

Dassen Island

Ystcrvark PointStru i sbaai

Capc St FrancisNear Vondeling lslancl

Wcst of Saldanha Bay

Capc Rccil'e

South rvest ofDasscl Islancl

Dyer lslandEilstern Cape

Ciapc Tou,rr Harbour

North ol'Robben Island

15,000 crude

1.0006 10,000 crudeUnknown

1 0,000 cnrde + tiel200 tiel

3 1,000 crLrde + fuel

300 luel

I 60- I 90.000 crude

I .01 I lirel

up to 2,:1(X) fucl

UnknorvnLJnknown amount ol' fuel

150 irr harbour+ 5 in Tablc Bay

1.400 luel

3,000

-559

I .216+4,00r1

1.6(x)

4E8+

47+21

0 (.5,(XX)+ Ganncts)

1,1E0

r'. I0.(-)00

t.3321.200+

-5 6l

c. 1 9.(XX)

April 1968

Aug 1 970Feb l97l}.jar 1912

Aug 1972

Jul 1974

Dec 1911

Mar 1978

Aug 1983

Aug 198-5

Jun I c)9,1

Aug 199-5

Nor, 1996

May 199E

Jun 2000

20,000

1s,000

10,000

5,000

0

Rescue and rehabilitation success

Rehabilitation procedures at the SANCCOB centre have changedover the years and are constantly being refined. Over the pastthree decades aboutl 47o of sick and oiled African Penguins thatwere admitted to SANCCOB were released back into the wildin a healthy condition. However, release rates have improvedgreatly over the years (Figure 4), increasing from an annualaverage of 52Vo in the 1970s to78Vo in the 1990s. Between 1996and 2000, 847o of penglins admitted were released into the wildin a healthy condition. What makes this even more remarkableis the fact that release criteria have become a lot more stringentover the years. Currently, birds must pass the following testsbefore being released into the wild: a) the waterproofing abil-ity of the bird's plumage is inspected after swimming for aboutone hour; b) birds must weigh over 2.8 kg; c) red and whiteblood cell counts must be normal; and 4) blood smears are takento ensure the bird is free of any infection.

A comparison of the rescue operations for the two largest oilspills tells a story of lessons well learnt. Prior to the sinking ofthe Apollo Searn 1994, the greatest number of penguins rescuedwas probably the 1,751 penguins collected from Dassen Islandduring 197220. It is therefore no wonder that conservationorganisations were ill prepared for the 1 0,000 African penguinsthat were oiled when the Apollo Sea sank near Dassen Island.The lack of sufficiently aerated containers for transporting oiledbirds and the overloading ofboxes resulted in more than 1,700birds dying during transportation from the island to the rehabili-tation centre (mostly due to asphyxiation and stress)22. Inabil-ity to adequately stabilise the large number of birds arriving atthe rehabilitation centre resulted in a furlher 1,200 birds dying

5)$$(ocooc!<f,sgasC}c\.I <.-(sc0()f-r-.-r..-Lr."-cOcOcocoAC)6]Jiotb)(}cn(')c))bo)o,cn&c)olXj5E;6jbr(in]

Nel ef a/.: Conservation status and impact of oiling on the African penguin

Figure 3. Numbers of oiled African Penguins admitted to SANCCOB, 1970-2000

during their first24 hrs in the centre. Of the 6,900 birds thatsurvived their first 24 hrs in captivity, J 57o were released backinto the wild in a healthy condition.

Lessons learnt from the Apollo Sea spill were well heeded,and when the Treasure sank almost exactly four years later,rescue teams were far better prepared. This despite the fact thatthe number of potentially affected birds was more than fourtimes that of birds oiled in the Apollo Sea spill, or almost 25Voof the global population. Of the 20,000 oiled penguins that wererescued from Robben and Dassen Islands, incredibly more than907o survived to be released back into the wild in a healthy con-dition23. A further 19,500 clean penguins were evacuated fromthe islands and transported to A1goa Bay (some 800 km by road)in an effort to prevent them from entering the polluted watersaround their breeding islands. This too was a great success andonly 24l birds died during transportation23. The first birds com-pleted the 900 km swim home in only 11 days, whilsr themedian time was probably a week longer. By this time the oilhad cleared, allowing these birds to escape almost certain oil-ing.

The cost of penguin rescue and rehabilitation

Real costs of rescue and rehabilitation operations are difficultto determine owing to the voluntary nature of much of the work.The best available estimates of costs incurred are insuranceclaims placed by organisations involved in rescue and rehabili-tation operations.

The total insurance claim for the rescue and rehabilitation ofseabirds during the Apollo Sea oil spill was 2,149,375 SouthAfrican Rands2a (equivalent at the time to some US$ 589,000).

How does oil affect penguins?

Being flightless and spending most o1'their tirne at sca, at or near their insulation and waterprooting, will not return to sea to fbrage.the surface of the ocean, Afican Penguins are particularly suscep- Ifnot rescuecl. they will ultirnateli, clie fiont hypotherrria, clehyclia-tible to rnarine oil pollution. Il'oil covers their f'eeding glounds or tion, or starvation. Furthermore, oiled pengnins will artcmpt togets ont() their landing areas at the breeding colony. it is inevitable remove the oiI frorTr their f-eathers by preening thernse]vcs. Thisthat penguins will becorne oiled. Oil causes the bircls' feathers to only results in birds ingestine oil. which in turn can leacl to ulcerl-clurnp' breaking dowtt their natural insulative ancl waterproofing tion of intelnal organs. anaemia and petro-chemical poisoning.properties. Oiled penguins tend to come ashore and, having lost

100

Nel & Whittington (eds): Rehabilitation of oiled African Penguins

Figure 4. Proportion of oiled birds admitted to SANCCOB that were released back into the wild in a healthy state.

- r \ -: q La, (C N cO o O - \ o < Lr) (O N o) O) - \_ N - <f LO 6 N € 6O< ( F- N \ r ir s - i1 o 6 ao co m moo co co - o) (I, aic') or .l f cf o) clC' O] o) O-) Clr Ol 0) o) C) .]) 0 (, Ol Cr 0) s) (,) 6) CD fi 5] s) Ol Ol o) *) $, 0, (l f, Orsr-C!

The cost per pcngr-rin rescuecl, r'ehabilitated and released backinto the rvild in a hcalthy conclition was thus R,+12 (USS I l2).The seabircl rescue ancl lehabilitation insulance claim for theTrea.sure spill was 10.166.544 Run.lslt (cqui\ rlent to aboutUS$ 1,.159,(X)0 at the tirne). ol R628 (US:li 90) per penguin re-leased back into the wild in a hcalthy condition. The decrease

in the USli cost pcr rcleased bild in the 'l'rcttsure spill. comparecl

ro rhe Apoll.o Sar spill. was probably attributable to the higherrelease rate during the Trea.sLrre spill (i.e. rnore rescued birdsslu'vivecl to be releasecl).

Efforts to rehabilitate seabilds in othel palts o1'the worldhave been extremely expensivc. The lescue and rehabilitationof thc 800 seabirds that sr-u'vived to be released durin-u the Er.ronVttldez sp1lt in Alaska cost some US$ 4l million26 (USlj 51,000per bilcl).

There are trvo main reasons for the lorv cost fol the rehabili-tttion of Afl'icirn Pen-quins. Firstly, African Pcngr-rins ale physi-call1, very tough ancl rr:rbust and thus able to deal with the res-cue" cleanin-u and rehirbilitation process far better than otherspecies. Scconc'lly. the existence o['a well-managed rehabilita-tion facility with trained and expelienced staff and volunteersgreatly reduces the initial setlrp costs and increases rel.rabilita-tion success. Althou-gl.r SANCCOB has been able to reclain-tcosts lionr the insulers of vessels involved in thc tr,io ma-ior

spills. the cost of kccping this facility in a stlte of operationalreadiness bctween spills is 1arge. Furtl.rermore. smaller spills thatale constantly chipping away at the penguin population are

rrostly o[ unknown oligin ancl costs are tl'rerefbre not recover-able.

Conclusions

Currently oiling is one of the principal threats to the thrcatenedAfl'ican Pengtrin. Although thc bcst solution woLrld be to avoidoil spills, the lr'equency of both catastrophic as well as chronicoil spills has inclelsecl dur:ing thc last decade. Without etlortsto rescue and rehabilitate Alrican Penguins, a thild of the glo-bal population coulcl have been lost between i994 and 2000.Hower,er, r'ehabilitation eflbrts by SANCCOB in collabcilationwith intern:rtional seabird resclle expcrts and local ronserr ittiouagencies have been l-righly successful and currently tnore than80% ol oiled bilds are releasecl back inkr the wild in a healthystate. Returns fix investments by conselvation-rnincled donorsare thus very good. witl'r costs ol- Iess than US:B 100 to rescue a

penguin tionr ccrtain death by oiling. But the continucd success

of cleaning oiled penguins lequires that thc rehabilitation facili-ties and the expertise of SANCCOB bc maintained in a state tll'readiness between oi1 spills.

References

l. Crawfbrd, R.J.M., Wi1liams, A.J., Hofmeyr'. J.H.. Kla-ses.

N.T.W.. Randall. R.M., Cooper. J., Dyer, B.M. & Ches-selet. Y. 1995. Trends of African Penguin SpltenisctLstlemer,yus popr-rlations in the 20th century. South Afi'it:tu'L

JoLtrnal of Mtrine Science l6: 101 I 18.

2. Crawford. R.J.M. 2000. African Pcnguin Spheni.sctt.td.enrcrstts.ln: Barnes. KN (ed.), The Eskom Red Dotu Bookof Birds of South A.fric:o, Le.sotho ttnd Swrlzilutd Birdl-it-eSouth Afiica, Johanncsburg. pp. 56 -57.

3. Barnes, K.N. (ed.). 2000. Th.e Eskont Retl Data Book olBirtls o.f Sofih Af rit:a, Lesotlto untl Sv,ttziluna. BirdLif'eSouth Afl'ica, Johannesburg. 167 pp.

,1. Birdl-ife International 2000. Threatenetl Bi.rds o.f tht:Worltl. Lynx Edicions and Birdl-ile International. Bar:ce-

lona and Cambric'lge, UK. 85 l. pp.5. Underhill. L.G. 1996. Proposals frorn South Aflica l'or

amendmerrts to Appendices I and II of the Conventi()n r)rl

the Conservation ol Migratory Specics of Wild Anirnals(tl-re Bonn Convention). Avian Denrogr. Un.it RescorcltReport 14: I 18.

6. Siegfried, W.R. & Crawford, R.J.M. 1978. Jackass Pcn-guins, eggs and guano: dinrinishing resources at DassenIsland. .loarft African .lountoL of'SL:ierLce 7rl: 3u9-390.

7. Ranclall. R.M. 1989. Jackass Penguins. In: Payne, A.I.L. &Crawtblcl, R.J.M. (cds), Oceans o.f lilb olf southern AJiicu.Vlaebelg, Capc Town. pp.241-256.

8. Crawtbrcl, R.J.M., Williarns, A.J., Randall, R.M., Randall.B.M.. Berruti. A. & Ross, G.J.B. 1990. Recent populationtrencls o1'Jackass Penguins Spltenist:tts clemer.stLs off south-ern Aliica. BiologiL:al Con,servatictn 52 229-243.

9. Adams, N.J. 1994. Patterns and impacts of oiling of Afii-can Penguins Spherti.st:u.s denrcrsus'. 1981 1991 . Biologi-c'ol Conservution 68'.3-5 41.

10. Shaughnessy, P.D. 1980. lnfluence of Cape Ful Seals onJackass PengLrin numbers at Sinclair Island. Soatft AfricanJournal of Wildlife Re,seurch l0: l8 21.

ll. Gildenhuys. A. & Williams, A.J. 1996. Cape Fur Sealspleying on Afl'ican Penguins at Dyer Island, South Africa.Third Intt:rnatiot'Lal Penguin Con.fere nce, Cape Town,

Nel eI a/.: Conservation status and impact of oiling on the African penguin

1996. Programme and abstracrs. 20 pp.12. Wilson. R.P. & Wilson, M.-P.T. 1995. The fbraging behav-

iotr of the Afiican Penguin Splrcni.scLr.s denrcrstt,t.ln: Dann,P.. Norman, I. & Reilly, P. (eds), The penguin,s: ecctlog,-tLntl nutntrgenreirl. Surrey Beatty Sons. Chipping Norton.pp.244 265.

13. Wilson. R.P., Wilson, M.-P.T. & Dutfy. D. 1988. Contem-porary and historical patterns of Afr-ican penguin Sphen-isL'tts tlemersus distribution at sea. Estuarine, Coa,ttol. ancl.

ShelJ Science 26 411-458.14. Crawltrrd, R.J.M. 1981. Distribution, availability and

rnovements of anchovy (Engralli.s caltensis) off SouthA1iica 196,1 1916. Fislteries Bulletin SouthAfrico l4: 5l-94.

15. Crawtbrd, R.J.M., Shannorr, L.J. & Whittington, p.A. 1999.Population dynamics of the Aliican Penguin Sltheniscu.sdentersus at Robben Island, South Africa. Marine Omitfutl.-ogt 27'. 139-141.

16. Green, L.G. 1950. At clu-tbreuk.f'or the ls/e.i. HowardTimmins, Cape Town.

l'/. Rand, R.W. 1970. Some hazards to seabirds. Os.trich sup-ltletrLertt 8: 515 -520.Eclwards. R.A. 1963. Treatrnent of "washed up" pcnguinr.Boknutkierie l5'. 8.

Westphal. A. & Rowan, M.K. 1970. Sornc observations onthe el' cts o1'oil pollution on the Jackass Penguin. Oslricltsttlt1tlent.cttt 8: -521 -526.Morant. P.D., Cooper. J. & Ranclall. R.M. 198 l. The rehabil-itation of Jackass Penguins Spht,niscu"r demersu.s lglO-

1980. In: Cooper, J. (ed.), Prot.aedittgs oJ the St,rtrpttliuttton Birds of the Sea and Shore, 1979. Al-rican SeabirdGloup, Cape Town. pp.267-30l.Moldan, A.S. 1989. Marine Pollution. In: Payne, A.l.L. &Crawfbrd, R.J.M. (eds), Ot'eans oJ'life oJJ southent Africa.Vlaeberg Publishers, Cape Town. pp. zll 49.Williams. A.J. 1995. Factors to consider in thc captr-u-e andtransport of penguins. ln: Barrett. J.. Erasmus, Z. & Wil-liams, A.J. (eds), Proceedin,qs; Cottsrol Oil Spills: Ef fect ortP e n g u it'r C o nt m un i ti e s and R e h ab i I it o t i o n P r o t: e tlu r e.s.

Cape Nature Conservation. Cape Town. pp. l-5-18.Crawford. R.J.M., Davis, S.A." Har.ding, R.T., Jackson,L.F., Leshoro, T.M., Meyer, M.A., Randall, R.M., Undcr-hitl. L.G.. Upfold, L., Van Dalsen. A.P., Van der Merwe.E,.. Whittington, P.A.. Williams, A.J. & Wolfaardt. A.C.2000. Initial impact of the Treasurz oil spill on seabir-ds ofl'western South Afiica. South African .lournal. o.f Marin.eScience 22: 157 116.Erasmus, Z. 1995. An overview ol the Apollo Sea incident.ln: Barlett, J., Erasmus, Z. & Williams, A.J. (eds), proceed-

ings: Coastul Oil Spills: EJfec't ctrt Penguin Contnnutitic.yctntl Rehobilitution Proceclure^i. Cape Nature Consen ation.Cape Town. pp. 15 18.

SANCCOB. Pcr.ortal eonununieatitrn.Sharp. B.E,. 1996. Post-release survival of oilecl. cleanedseabirds in North Arnerica. Ibi.s 138: 222-228.Whittington, P.A. 2002. Survival ancl moventenrs of Afr-i-can Pengr-rins, especially after oiling. PhD thesis, Univer-sity of Cape Town. South Africa.

21

22.

23.

11

18.

19.

20.

25.26.

lt.

Post-release survival of rehabilitated African Penguins

PHIL A. WHITTINGTONl

l Avian Demography Unit, Department of Statistical Sciences, University of Cape Town,Rondebosch, 7701, South Africa, e-mail: pwhit@adu.uct.ac.za

Abstract

Whittington, P.A. 2003. Post-release survival of rehabilitated African Penguins. In: Nel, D.C. & Whittington,P.A. (eds), Rehabilitation of oiled African Penguins: a conservation success story. BirdLife South Africa and

the Avian Demography Unit, Cape Town, South Africa. pp. 8-10, 15-18.

The efficacy of SANCCOB's rehabilitation of oiled African Penguins was tested by conducting intensivesearches for flipper-banded penguins at breeding colonies between 7994 and 1999. The survival of rehabili-tated birds was investigated by assessing the proportion of released penguins that return to breeding colonies,

the length of time between release and death, estimation of survival rates using the computer package MARK,and an analysis of penguins that were known to have attained an age of 20 years or more in the wild. Attemptsto clean oiled African Penguins and rehabilitate them back to the wild have been largely successful. Post-release

monitoring of African Penguins from four different oil spills revealed that up to 817o of rehabilitated penguins

returned to breeding colonies. An analysis of recoveries of penguins that had died within a period of ten years

after banding or release showed that the median number of days survived by rehabilitated penguins after release

was similar to that survived by penguins unaffected by oiling incidents. The mean annual survival rate ofrehabilitated adult African Penguins was found to be 0.79 (197o), similar to the figure of 0.81 (817o) for non-oiled adult penguins banded at Robben or Dassen Island. The six oldest birds known from the wild includefour that had been treated by SANCCOB, one of which had been oiled and cleaned. The latter bird is the world'soldest known survivor from an oiling incident, having been at least24 years old when last sighted alive. Anassessment was made of the success in hand-rearing chicks that had been orphaned at Dassen Island by an

oil spill in 1994. The proportion of the hand-reared chicks that survived to breeding age was found to be similarto that of naturally fledged chicks from Dassen Island in the same year.

Post-release monitoring of rehabilitated AfricanPenguins

After days and weeks of cleaning, feeding and nursing AfricanPenguins that have been oiled, it is a wonderful experience tosee them regain their freedom. They usually hurry down thebeach, stop to find their bearings and then take their first plungeback into the ocean. But what happens to them afterwards? Dothey return to their breeding colonies? Do they live out a normallife-span? Or do they fail to make that crucial transition back tothe wild?

These are questions that can only be answered by intensivemonitoring work following an oil spill. The ecological and eco-nomic value of cleaning oiled birds has been questioned bysome. Frost et al.\ considered that it contributed "little to con-servation in real terms", whereas Randall et al.2 were of theopinion that cleaning oiled African Penguins does serve a con-servation function. Sharp3 pointed out that in North Americaand Europe, available data lead one to the conclusion thatcleaned and treated seabirds do not successfully make the tran-sition back to the wild. In fact, the whole question of whethercleaning oiled birds serves any useful function or is merely ahuman "feel-good" exercise, but really an expensive waste oftime, effort and resources, has been raised. The only way toapproach this question is with a sound analysis of scientific dataand this has been achieved with SANCCOB's work on AfricanPenguins.

In order to assess how successful rehabilitation of oiled pen-guins has been, and thus justify the costs of rehabilitation intime, effort and money, it is necessary to be able to identifyrehabilitated individuals in the wild. The most successfulmethod of doing this is to fit a specially designed metal flipper-band to each bird, shortly before they are released from the re-habilitation centre (see box on p. 10). This band will last for thebird's lifetime and the unique letter/number combination usedon the band allows each bird to be individually recognisable.Several years of intensive monitoring are required to assess fullythe success of a rehabilitation effort. Southern Africa is fortunatein this respect. African Penguins are not highly migratory birds.Although they may forage away from their breeding coloniesand may travel up to 2,000 km in their first year or so of life,adults generally remain within their breeding range throughoutthe year. Monitoring work is also facilitated by the fact that mostof the breeding colonies are easily accessible to researchers.Scientists have also banded penguins for reasons other thanfollowing those involved in oil spills. Adult penguins and chickshave been banded at breeding colonies in order to investigatetheir movements, breeding success, age of first breeding andannual survival. This means that there is a large sample ofbanded birds that have not been oiled or cleaned, against whichthe performance of the oil spill survivors can be measured.

The most intensive period of monitoring penguins began to-wards the end of 1994, following what had then been the worstoil spill to affect African Penguins. Of the 10,000 penguins oiled

80

70

Whittington : Post-release survival

5 E FE 8

^60ET'Eso.9)oE40tr.9b30CLoo-^

ZU

't0

1994 1995 1 996

afiel the sinking of the bulk ore carricrATrollo Seo. -5,200 died,most within 48 houls of being rescued4. However, the remain-cler were successfully cleanecl and released. ,1076 having beenfitted with l'lipper-bandss. A.joint ploject of the Avian Demog-raphy Unit, Marine and Coastal Management and Western CapeNature Conservatior-r Board set out to establish the success ofthis operation by sealching for tlipper'-banded penguins ut nsmany breecling colonies as possible. Eftbt'ts wel-e concentratedon the two colonies that were r.r,orst af1-ected by the spill: DassenIsland, where Western Cape Natr-rrc Conservation Board alsomonitorecl the breeding success of oiled bir-ds, and RobbenIsland. Other colonies, such as Dyer Island ancl the islands inSaldanha Bay, were visited more opportunistically, usually 34 times a year. StafT of Port Elizabeth Museum. working on theislands in Algoa Bay, and of the Ministry of Fisheries andMarine Resources fiom the olfshore islancls of Narnibia alsocontributed sightings ol'flipper-banded birds. Other sightings olbanded penguins, made by the general public, were lirwardedto the South Atlican Bird Ringing Unit (SAFRING) ar rhe Uni-versity ol'Cape Town.

During the course of the project, other oil spills occurred. Asmall spill of unknown origirr oiled 1,332 penguins at DyerIsland in August I9956. The Cortliglie nL sank olf the EasternCape coast in November 1996, oiling r:rver 1,200 penguins. Aburst pipeline in Cape Town Harbour in May 1998 oiled a fur-ther 563 penguirrsT. Penguins rehabilitated front these spillswere also bancled prior to their release and tl-reir subsequentpro-gress was monitored. The lieldwork involvecl painstakinghours of searching in burrows. under rocks and under br-rshes forflipper-banded pengnins and using a telescope to reacl bandnumbers of penguins on the shore. The result of these ellbrtswas a database containing 5-5,800 sighrings of I 1,800 ditltrentpenguins.

The itssessment of the success of clcanin-g operations, withregard to survival of the penguins al'ter release. was made in flveways:

1997 1 998 1 999

1 . Shorl-term: nurnbers of leleased penguins recordcd back atbreecling colonies.

2. Long-ternr: for penguins thlt were recovereri clead u,itl-rinten years fiorn banding, thc tirne between bancling and deathwas compared between cleiinecl hilds and non-oilecl bircls.

3. Estin'ration of survival rates using the software packageMARKE.

4. Longevity of Afl-ican Pengr-rins.5. Sulvival of hancl-realed orphaned chicks to breeding a-ee.

Both 2 and 4 relicd on data from penguins oiled in incidentsplior to 199,1, going back as far as the early i970s.

1. Numbers of rehabilitated penguins recorded backat breeding colonies

Three incidents that occurrecl between 1994 rind 1998 wer-cclosely nronitored: the Apc.tllt:t Sca spill of June 1994. the DyerIsland spill of Au-eust 199-5 and the Cape Town Harbour spillol May 1998. Thc first of these plovicled the lalgest san'rple ofbanded penguins and the longest pcriod of ntonitorin-q (fiveyears). The lirst indication that the cleaning and release ol'pen-guins li'orn the Apollo Sca spill had been successf'ul was the lackof dead penguins lbund shortly after lelease. Hacl the operationnot been successful, we would havc expected a lar.ger thanavera-ge number of penguins to have bcen fbund c1ead. This wasnot tl're case. In fact, the proportion of cleanecl penguins thatwcre found dead within the fi'st two yeals atter the spill wasclose to the total th:rt would have been expectecl fron'r a similar-sized sarnple of he:rlthy, non-rrilcd pen::uins5. This was still thecase after five years had elapsed('. The number of cleaned pcn-gr-rins re-sighted in the wild rose sharply during the first twoyears fbllowing tl'reir release betbre levelling off in subsequentyears (Figure l). Five years after the Apollo Scrr spill. a total ol'2,962 penguins hacl been recorded back at brceding colonies:alrnost 737c of those released al'tel the spill. This is lirrthcr evi-

qt3

Date

*r*-* Apollo Sea -+- Dyer lsland Cape Town Harbour

Figure 1. Proportions of rehabilitated African Penguins from the Apollo Sea, Dyer lsland and Cape Town harbour oil spills that werere-sighted after release.

.1 0 Nel & Whittington (eds): Rehabilitation of oiled African Penguins

A flipper-banded African Penguin from theApollo Sea oil spill. Photo: L.G. Underhill.

Penguins and

Bird rings have now been in use fbr about 100 years and are a triedand trusted method fbr trarking bircls so that they can be individu-ally recognised. The rings used on penguins are placed on the

flipper and are really ovoid bands, rather thiln rings. The shape ofthc band mirrors the cross-section of the penguin's flipper and is

somewhat torpedo-shaped when seen fiom above. This rnakes the

fit as good as possible and recluces the amount o1"'drag" caused

h1 the birntl u hett tl)e p,'nguin is :tt inttning.The bands are presently made fiorn stainless steel and have a

letter pretix and lour or five numbers engraved on one side. They

cirn be read in the field r.rsing binoculars or a telescope. On the

reverse side ol'the band is a contact address. so that anyone who

fincls it can report the details to SAFRING and receive some

inlormation on where and rvhen the bird was banded.

Ii you lind a ring or ar-e able to retld the number in the field,please intbrm SAFRINC at the Avian Denrography Unit, Depart-ment of Statistical Sciences, University of Cape Town. Ronde-

bosch,770l, South Africa, telephone (021) 650-2421, fax (021)

650-3434, e-mail SAFRING@adu.uct.ac.za. They will need toknow the ring or bancl nuntber, the species (if known). date and

locality of l'inding.

flipper bands

Penguin flipper-band as seen from above.

dencc that the rehahilitation of oiled penguins hacl bcen success-

1u1. The reporting late of lehabilitated pcnguins that were tbunddead lbllowing releasc has lernaincd below that expected fiottla sirnilu'nLrrnber ol non-oiled penguins. This indicates that the

pcngr-rins wcre not .just rcturning to breeding colonies to diesholtly afterwarcls but that they remained alive ltrr some consid-

erablc tirne. This is suppot'tecl by the number of clcaned pen-

guins that were knowtt to hiivc sulvivecl into their second, thirc1,

fburth and fifth yeu's aftel the oil spill.Finding f-lipper-bandcd penguins on ol'l'shotc islands is not

an easy task: tl're penguins do not always conveniently prcsent

their band nutnbcrs tbr iuspectiort by researchers! At Dassen

Islanil. nrany o1 the penguirts ncst ilt br.tt'rows, making it hard to

t'ind thcrn. At Robbcn Islanc[. thc tl'rick covcl of alien Aczrcla and

Mutitoktt also lendet's it difficult to track down flipper-bandeclpenguins. Consequentll,. it is certain that banded birds werernissed by lesealchers and the nurrbers and ploportions ofpenguins re-sighted shoulcl bc viewecl as the bare rlrinima ofthosc thrt had survived. Penguins that were rehabilitated afier

being oiled in the Apollo Sea incident were still being seen forthe first time over five years after their release. The degree ofsuccess of the cleaning operation is thus likely to be greater than

that actually recorded.The pattern for the other two spills mentioned was similar to

that.of the Apollo Sea (Figlure 1). However, the proportion ofpenguins re-sighted from the Dyer Island spill is considerablylower than the proportions seen after the other two incidentsmentioned. The reason for this is not immediately apparent,

although Dyer Island, the colony affected by this spill, does notreceive the intensity of monitoring effort that either RobbenIsland or Dassen Island, the colonies worst affected by the othertwo spills, receives. This may have reduced the proportion ofbirds recorded following release. However, Dyer Island is rela-tively small when compared to either Dassen or Robben Island.

It now has fewer penguins than either of these two colonies(Table 1) and they are forced to nest on the surface and are there-

fore easier to find than the large numbers that nest in burrows,under rocks and under bushes at Robben and Dassen islands.

Front

11

Rescue and transport

a) Oiled penguins on Robben lsland, during lhe Treas-ure spill.

b) Catching oiled penguins.c) Transferring oiled penguins to aerated boxes for

transport.d) Loading boxes of oiled penguins onto a boat,

Dassen Island.e) Loading boxes of oiled penguins into a helicopter,

Dassen lsland.

Photo credits: SANCCOB archive (a), A.P. van Dalsen(b), A.C. Wolfaardt (c, d, e).

12

a)

Stabilisation and cleaning

a) Oiled penguins arrive ai the SANCCOB rehabilitation centre.b) Re-hydrating an oiled penguin with an electrolyte solution.c) Oiled penguin enters the wash.d) Oil being removed from feathers.e) Cleaned penguin being fed.

Photo credits: P"A. Whittington (a), A"P. van Dalsen (b, d, e),C. Loch-Davis (c).

I n .i'I'i, *." '*

if,P',

Rehabilitation and release

a) Thousands of penguins inside the Salt River warehouse, dur- are in prime condition for release.e) Cleaned and fully rehabilitated penguins are released.

Photo credits: A.P. van Dalsen (a, e), S. petersen (b, c, d)

14

a)

d)

Reintegration and lollow-up research

a) Rehabilitated penguin, from the Treasure oil spill, with twohealthy chicks.

b) Searching for flipper-banded rehabilitated penguins along theshoreline, Dassen lsland.

c) Following the growth of two small chicks producedby ApolloSea rehabilitated parents.

d) Two fully feathered chicks, raised by Apollo Sea rehabilitatedparents, ready to go to sea.

e) Clean penguins!

Photo credits: L. Upfold (a), H. Ratz (b), J.L. Nel (c, d), A.C. Wol-faardt (e).

Whittington: Post-release survival 15

Table 1. Numbers of breeding pairs of African Penguins at Dassen,Dyer and Robben islands, 1 995-1999. Data courtesy of Marine andCoastal Management and Western Cape Nature ConservationBoard.

Year Dassen lsland Robben lsland Dyer lsland

Table 2. Proportions of African Penguins re-sighted by October1999 following three oiling incidents.

lncident and date Adults Juvenilesre-sighted (%) re-sighted (%)

i 995r 996t991I 99E

I 999

79

5l6t)

Innestigation of the database reveals another difference fromboththe Apollo Sea and Cape Tolvn Harbour spills. In the lattertwo incidents, the majority of penguins re-sighted were seen atthe islands immediately affected by the two spiIls, i.e. Robbenand Dassen islands. However, most(727o) of the penguins oiledin the Dyer Island spill were later re-sighted at Dassen Island,suggesting that they were Dassen Island birds that had beenforaging around Dyer Island when they were oiled. This hasimportant repercussions for the release procedure of cleanedpenguins. It demonstrates that releasing penguins as close aspossible to their point of capture is not always the best policy.Given the ability of penguins to find their way back to theirbreeding colonies, it would seem to make more sense to releasethem as close as possible to the rehabilitation centre. This wasdone followin gthe Treasure oil spill in 2000. These differencesbetween oiling incidents and the rehabilitation success fromdifferent spills highlights the importance of monitoring pen-guins affected by future oil spills.

Only 16 months of re-sighting data were available for pen-guins oiled in the Cape Town Harbour spill. The number of pen-guins re-sighted one year after their release (507o) comparesfavourably with the 45Vo ofApollo Sea birds seen one year aftertheir releaseT. The signs are therefore good that the rehabilita-tion effort from the Cape Town Harbour spill wilt be equal inits success to that of theAp ollo Sea. The number of cleaned pen-guins that were found dead did not exceed the numbers thatwould be expected from similar-sized populations of non-oiledpenguins in any of these three incidents.

The proportions of penguins oiled in adult plumage that werere-sighted following release were greater than those ofbirds oiledwhen still juvenile. This was the case in all three of the incidentsdescribed above (Table 2), although the proportion ofjuvenilesseen one year after the Cape Town Harbour spill was nearlydouble the corresponding proportion seen five years after theApollo Sea spill. This suggests that birds in their first year have ahigher mortality rate than those that have attained adult plumage.

The highest proportion of released penguins recorded backat a breeding colony was 87Vo. This was based on a total of 101penguins released from Robben Island after being oiled in anincident at St Croix Island, Algoa Bay, in 19792.

23

l911

2. Elapsed time between banding and death

This analysis was performed on full-grown African Penguinsthat were found dead within ten years of their having beenbanded. In this instance, full-grown refers to penguins that hadalready left their natal colony, i.e. it excludes those banded as

chicks. The length of time between banding and death was com-pared between rehabilitated penguins and those that had neverbeen oiled or treated. If rehabilitation efforts were unsuccess-ful, one would expect the average time elapsed between band-ing and death to be shorter for rehabilitated penguins than fornon-oiled birds. A randomisation test was performed on the datato test whether rehabilitated penguins survive as long as non-oiled penguins after banding. This test allows different percen-tiles of the population to be tested and has the advantage thatsurvival rates are not required to conform to a parametricmodel9-

The median elapsed times between banding and death at fourpercentiles of the population differed by a maximum of threemonths between the samples of non-oiled and of rehabilitatedAfrican Penguins (Table 3t. The 50th percentile represents theyoungest half of the population at death. The 95th percentileincludes all but the oldest 57o of the sample. From Table 3 it isclear that the test results are not significant and that the nullhypothesis of equal elapsed times for the two groups is ac-cepted. This suggests that rehabilitated penguins survive equallywell in the wild as penguins that have never been oiled.

This result differs from that found in other parts ofthe world.The median time elapsed between release and death for threespecies of North American seabirds that were rehabilitated fol-lowing an oil spill was less than 10 days3, comparedto 23months for the youngest 50Vo of rehabilitated African Pen-guinse. If the median elapsed times between banding and deathare compared for the three North American species, the non-oiled birds survived 36 to 52 times longer than rehabilitatedbirds3. In contrast, non-oiIed, full-grown African Penguins sur-vived 1.2 times longer than cleaned penguins; and if the sampleis restricted to penguins banded in adult plumage, this ratio isreduced to l:1e. This evidence implies that the North Americanseabird species did not make a successful transition back intothe wild after cleaning. Results from the United Kingdom areequally depressing; the median time which had elapsed betweenringing and death for rehabilitated Guillemots (Jria aalge was

9.192q 50)

8,651

r 0,918t 5 t55

2.219

3.097

-1. -1 -1 O

3.161.+,399

1,260I )74) 14\1,963

I,JOJ

Alnl.lo Se u. 1991Dyer Islanci, I99-5

Ciape Town Harbour. 1998

Table 3. Time elapsed (months) between banding and death of African Penguins that were banded when full-grown, truncated to ten years.The null hypothesis of equal elapsed periods until death of non-oiled and cleaned penguins is rejected if p<0.05.

Non-oiled (n = 163) Cleaned (n = 147)

Percentile Months elapsed Confidenceintervals Monthselapsed Confidence intervals Test for difference

5015

9t)

95

2t53

89

108

It3

-50

9l106

( r-5, 25)(36, 65)(76. e9)(92. r l3)

(1,21)(,{0, 62)(70. 100)(93, r 12)

P = 0.15

P = 0.E6

P = 0.83

P = 0.u9

16 Nel & Whittington (eds): Rehabilitation of oiled African Penguins

Table 4. Details of the 10 oldest African Penguins known from the wild

Band number Age atbanding

Treated atSANCCOB

Date banded Date re-sighted Age at re-sighting(years)

P6593P.+210

P,l364P3265

P3399

P3111P12.31

P't311P335 r

P6t0r

AdultlmmatureImmatureAdultImmatureAclultlmmatureImmatureImmaturelmmtlture

\oYes

Yes

Ncr

NoYcsYes

NoNcr

No

30 Nov 1972

13 Sep 1972

l0 Aug 1973

06 Oct 1974

l2 Dec 1976

26 Sep 1972

i3 Sep 1972

02 Dec 1972

1l t)ec I97616 Marl977

28 Mar 1999

25 Sep 19913

04 Jan 1999

13 Mar 1999

30 May 2000

03 Oct 1995

0l Jan 1996

lTAug 1995

27 Mar 1999

27 Mrr l99c)

2l+ (doad)

26 27 (dead)

c .26 (dcacl)

>25 (alive)25 (rlivc)>)1 (alive)>21 (dead)

c.23 (nest.)

t .23 (alive)22 23 (+chicks)

seven dayslo. Attempts have been made to clean oiled MagellanicPenguins in Argentina but none were seen after release and

rehabilitation was stated to be "of little use"3. SANCCOB has

by far the best record of successfully returning oiled birds backinto the wild.

3. Comparison of survival rates from live re-sightings

Live re-sightings of African Penguins banded at Dassen Islandor at Robben Island were used to estimate survival rates usingthe program MARK, which allows various different models tobe tested on the data8. The program uses Likelihood Ratio Tech-

niques to estimate survival between specified periods, in thiscase a year. The user can specify a variety of models, e.g. sur-vival rates can be set to change over time or be different fordifferent age groups. The most parsimonious model tested isthat which best fits the data and gives the most precise estimatesof survival and re-sighting rates. Akaike's Information Criterion(AIC) is used by the program as a guide to selection of the mostparsimonious model. See reference8 for further details.

Using re-sighting data for the years 1989-1999, the average

annual survival rate of non-oiled, adult African Penguinsbanded at Robben Island or at Dassen Island was found to be

0.81 (817o)6. The same procedure was followed uqing AfricanPenguins that had been oiled and cleaned. It was rarely knownfrom which colony the cleaned penguins had come prior to oil-ing, so all the available data for the years 1990-1999 were used.

The average annual survivalrate of 0.19 was similar to those ofnon-oiled penguins banded at Robben and Dassen islands. It ispossible to compare the survival rates of rehabilitated penguins

with those of non-rehabilitated birds using MARK to see if theydiffer. This is done by treating the non-oiled birds as one groupand the rehabilitated birds as another group. Models can thenbe tested that apply different survival rates to each group or thatapply the same survival rates to both groups. To make this com-parison even, the non-oiled group included all penguins bandedas adults, i.e. not just those banded at Dassen and Robbenislands, pver the same span of years (1990-1999).

The most parsimonious model represented a situation wherethe same suryival rates were applied to both groups6. The factthat this model was chosen suggests that survival rates ofreha-bilitated and of non-oiled penguins do not differ significantlyfrom each other; another indication that rehabilitated penguins

survive equally well after release as those that have not beenoi1ed.

4. Longevity of African Penguins

The oldest known African Penguin in the wild was at least 27years old when it was killed in a traffic accident in Simon's

Town, near the Boulders penguin colony, in 199911. It is one of26 Afican Penguins that are known to have lived for 20 years

or more. Of these 26 penguins, five were treated by SANCCOB,at least one of which had been oiled and cleaned. The latter birdwas at least 24 years old when last sighted alive and is thoughtto be the world's oldest known surviving bird from an oilingincident. The 10 oldest African Penguins inthe wild includefour that had been treated by SANCCOB (Table 4)11.

Of the penguins known to have survived into their twenties,23 were fitted with flipper-bands prefixed by the letter "P".These bands were used in the 1970s; 7,656 (18Eo) were fitted topenguins at breeding colonies and2,209 (22Vo) to penguins thathad been treated by SANCCOB. If rehabilitated penguins sur-

vive as well in the wild as non-oiled penguins, we would expect

similar proportions to be reflected in the oldest 23 penguins thatwere fitted with "P" prefix bands. Of these 23 penguins, five(22Vo) were rehabilitated by SANCCOB, which is identical tothe expected proportion. Yet another indication that, as far as

survival is concerned, rehabilitated African Penguins dojust as

well as non-oiled penguins after their release back into the wild.

5. Survival of hand-reared orphan chicks

African Penguin chicks are not in immediate danger of beingoiled while at the nest, unless brooded by a severely oiled par-

ent. They are, however, impacted by oil spills if their parents are

oiled and die or are taken to a rehabilitation centre for several

days or even weeks. In the latter case, the chicks are effectivelyorphaned and are then likely to be predated or starve to death.

Consequently, attempts have been made to hand-rear the

larger African Penguin chicks orphaned by oil spills. This was

first done in 1994, following the Apollo Sea oll spi1l12. Of 507orphaned chicks that were hand-reared at Dassen lsland, 414were successfully "fledged", 437 havingbeen fitted with flipper-bands. A further 399 penguin chicks were banded at nests at

Dassen Island in 7994 pior to the oil spill, allowing a compari-son to be made of the survival of orphaned and naturally fledgedchicks.

Between October 1994 and October 1999,41 of the 437orphaned chicks (117o) were re-sighted at breeding colonies13.

Six (1%) were recorded breeding and eight (ZVo) were fornddead. Of the 399 naturally fledged chicks, 36 (97o) were re-sighted alive, five (l%o) were recorded breeding andfour (lVo)

were found dead. Although relatively few of the hand-rearedchicks appear to have survived to breeding age (4-5 years old),the proportion that did so was almost identical to that of the

chicks that fledged naturally. The proportions of orphanedchicks recorded breeding and found dead were also similar tothose of the naturally fledged penguins, as was their pattern ofdispersal after leaving the nest. This suggests that the hand-rear-

Whittington: Post-release survival 17

ing exercise was successful in producing chicks with an equalchance of surviving in the wild to those reared under natural cir-cumstances.

Of 50 chicks hand-reared after an oil spill at Dyer Island in1995, nine (18Vo) had been re-sighted alive by October 1999.No chicks were banded at nests on the island in 1995 with whichto make a comparison. It is still too early to assess the result ofthe survival of the larger number of over 2,000 chicks, orphanedand hand-reared following the sinking of the Treasure in Jtne2000.

Although hand-reared African penguin chicks survive aswell as naturally fledged chicks in the wild, the proportion thatsurvive to breeding age is low. Priority must therefore go tocleaning oiled adult birds, which have already survived thatmost critical first year of life and have a much greater annualsurvival rate. Furthermore, adult birds can potentially com-mence breeding immediately after release14, whereas hand-reared chicks are unlikely to breed until they are four to fiveyears old 6,1s.

The results of these five investigations are good news for theconservation of the African Penguin, but it is imperative thatmeasures are taken to minimise the risk of oil pollution if ourcoastal ecology is to remain in a healthy state. As well as beingpart of our natural heritage, the South African coast and itsseabirds attract many tourists and are also of considerable eco-nomic importance. The fact that SANCCOB,s work has consid-erably reduced the numbers of a vulnerable species that havebeen lost to oil spills, and that the African penguins they havecleaned, treated and released have survived as well as non-oiledpenguins in the wild, is a great tribute to the dedication of theirstaff and army of volunteers. However, this is not the wholestory. Even if cleaned penguins survive in the wild, it is of littleconsequence if they are unable to breed and contribute to thegrowth and stability of the population. So how does oiling,cleaning and treatment affect the breeding performance of theAfrican Penguin? This question is tackled in the next paperl4.

References

1. Frost, P.G.H., Siegfried, W.R. & Cooper, J.1916. Conser-vation of the Jackass Penguin Spheniscus demersus L. Bio-logical Conservation 9: 7 9-99.

2. Randall, R.M., Randall, B.M. & Bevan, J. 1980. Oil pol-lution and penguins - is cleaning justified? Marine pollu-tion Bulletin ll: 234-237.

3. Sharp, B.E. 1996. Post-release survival of oiled, cleanedseabirds in North Ameriia. Ibis I38:222-228.

4. Williams, A.J. 1995. Factors to consider in the capture and

transport of penguins. In: Barrett, J., Erasmus, Z. & Wil-liams, A.J. (eds), Proceedings: Coastal Oil Spills: Effect onPenguin Communities and Rehabilitation procedures. CapeNature Conservation, Cape Town. pp. 15-18.

5. Underhill, L.G., Bartlett, P.A., Baumann, L., Crawford,R.J.M., Dyer, B.M., Gildenhuys, A., Nel, D.C., Oatley,T.8., Thornton, M., Upfold, L., Williams, A.J., Whitting-ton, P.A. & Wolfaardt, A.C. 1999. Mortality and survivalof African Penguins Spheniscus demersus involved in theApollo Sea oll spill: an evaluation of rehabilitation effofts.Ibis 141: 29-31.

6. Whittington, P.A. 2002. Survival and movements of Afri-can Penguins, especially after oiling. phD thesis, Univer-sity of Cape Town, South Africa.

7. Whittington, P.A. 2000. The Cape Town Harbour oil spill- one year after the event. ADU Research Report No. 37.

8. White, G.C. & Burnham, K.P. 1999. program MARK: sur-vival estimation from populations of marked animals. BirdStudy 46 Supplement: 120-138.

9. Whittington, P.A. 1999. The contribution made by clean-ing oiled African Penguins Spheniscus demersus to popu-lation dynamics and conservation of the species . MarineOrnithology 2l : 177 -180.

10. Wernham, C.V., Peach, W.J. & Browne, S. 1997. Survivalrates of rehabilitated Guillemots. BTO Research ReportNo. 186.

11. Whittington, P.A., Dyer, B.M. & Klages, N.T.W.2000.Maximum longevities of African penguins Spheniscusdemersus based on banding records. Marine Ornithology28:81-82.

12. Gildenhuys, A. 1995. Capture, care and release oforphanedAfrican Penguin chicks at Dassen Island. In: Barrett, J.,Erasmus, Z. &W1lhams, A.J. (eds), proceedings. CoastalOil Spills: Effect on Penguin Communities and Rehabili-tation Procedures. Cape Nature Conservation, Cape Town.pp. 18-20.

13. Whittington, P.A. 1999. Survivors of the Apollo Sea o1lspill, five years later: a success story. penguin Conserva-tion l2(2): 18-19.

14. Wolfaardt, A.C. & Nel, D.C. 2003. Breeding productivityand annual cycle of rehabilitated African penguins follow-ing oiling. In: Nel, D.C. & Whittington, p.A. (eds), Reha-bilitation of oiled African Penguins: a conservation successstory. BirdLife South Africa and the Avian DemographyUnit, Cape Town. pp. 18-24.

15. Crawford, R.J.M., Shannon, L.J. & Whitrington, p.A. 1999.Population dynamics of the African penguin at Robbenlsland. Marine Ornithology 27: 135-143.

Breeding productivity and annual cycle of rehabilitated African Penguinsfollowing oiling

ANToN C. WoLFAARDTI & DEON C. NEL2

l Western Cape Nature Conseruation Board, Private Bag X5014, Stellenbosch, 7600, South Africa,e-mail: awolfaardt@kingsley,co.za;2BirdLife lnternational Seabird Conservation Programme, BirdLife South

Africa, PO Box 1586, Stellenbosch,7599, South Africa

Abstract

Wolfaardt, A.C. & Nel, D.C. 2003. Breeding productivity and annual cycle of rehabilitated African Penguins

following chronic oiling. In: Nel, D.C. & Whittington, P.A. (eds), The rehabilitation of oiled African Penguins:

a conservation success story. BirdLife South Africa and the Avian Demography Unit, Cape Town, South

Africa. pp.18-24.

The success of rehabilitation efforts is often measured by the number of individuals that survive to return totheir breeding colony. However, little is known about the effect of the oiling and the subsequent rehabilita-tion on the breeding productivity and annual cycle of rehabilitated birds that return to their breeding colony.At Dassen Island in the south-western Cape, a monitoring study was initiated soon after the first rehabilitatedAfrican Penguins were released following rhe Apollo Sea oll spill in June 1994. Six years after the Apollo Sea

spill at least 607o of the rehabilitated penguins had been recorded breeding. The breeding productivity of the

rehabilitated birds was, on average, no different to that of other penguins that were not affected by the oil spill.However, in a couple of the nest cohort comparisons, when both the Apollo Sea rehabllitated birds and birdsunaffected by the oil spill fared poorly owing to adverse feeding conditions, the rehabilitated birds did nota-

bly worse than the unaffected birds. These differences were restricted to only a couple of comparisons withinthe first two years of the study, highlighting the short-term nature of this impact. Other subtle and short-termimpacts of oiling and rehabilitation on African Penguins following the Apollo Sea oll spill included the

disruption of annual moult and breeding cycles, and breaking of pair bonds owing to the death or prolongedabsence of a partner. In the recent Treasure oi1 spill about 19,500 penguins were taken offDassen and Robben

islands to prevent them from becoming oiled. They were released 800 kilometres away aL Cape Recife in the

Eastern Cape province. Interim results indicate that the relocation of these birds was a remarkable success and

that relocated birds recover more rapidly than rehabilitated birds. Relocation and rehabilitation are not mutu-ally exclusive processes. Relocation of birds should be seen as an additional management tool, which can be

utilised when large numbers of birds are known to be threatened by oil pollution.

lntroduction

Rehabilitation of African Penguins is of little conservation valueif these birds do not go on to breed and thus contribute to thefuture of the species. The overall success of the rehabilitationprocess should therefore also take into account the reproductiveproductivity of birds after release. This does not mean that re-habilitated birds need to breed immediately after release, but ifthey never produce offspring again, they are essentially redun-dant to the population. It can even be argued that rehabilitatedbirds that never produce viable offspring actually have a

potentially negative impact on the breeding population by com-peting for limited food and other resourcesl. It is thereforeimportant to determine how many of the birds that survive tomake it back to their colony attempt breeding, and whether theoiling and rehabilitation have any effect on their subsequentbreeding success.

Oil contamination, and specifically oil which is ingested orinhaled by birds while preening contaminated feathers or whileconsuming contaminated food or water, has a number of effects

on birds that may affect their subsequent breeding success. It has

been shown that ingestion of oil can have a negative impact onthe endocrine system, interfere with the circulation of reproduc-tive hormones and lead to a suppression of egg-laying2. Oilcontamination may also lead to thinning of eggshells and reducethe viability of eggs, embryos and chicks3'4. It can suppress thebird's immunity to infections,6 and may also cause behaviouralanomalies resulting in reduced chick provisioning or nest aban-

donment7,8. Furthermore, it has been found that chicks of birdsthat have ingested oil may develop physiological abnormalitiesor show lowered growth rates and survivale.

Most of the studies of the effects of oil exposure on birdshave been investigations of laboratory or captive birds, and havefocused mostly on the short-term effects of oiling on breedingbiology. Very little information is available on the longer-termimpacts of oiling on the breeding productivity of penguins thathave been oiled, rehabilitated and released back into the wild.

Two catastrophic oil spills have affected the south-westerncoast of South Africa during the last decade. The Apollo Sea, a

bulk ore carrier, sank south-west of Dassen Island in Jlune 7994,

18

Wolfaardt & Nel: Breeding productivity and annual cycle of rehabilitated African Penguins

Figure 1. Proportion of returned Apollo Sea birds that have attempted breeding"

19

\f tf) {) u) (O q (O f.* f.' N cO A oO O) O'r S.r (ftr) c:, cn cri 6) ? ? ? ? ? q ? ? + ? E E+ = + + * ol o h ol c'l i ar () i- ol tl =3 ri 3 ai 3 ei g ri g ra 3 3

and the Treasure sank between Dassen and Robben islands inJune 2000. Approximately 10,000 and 20,000 African Penguinswere oiled during these two events respectively. Ongoingfollow-up studies of African Penguins oiled and cleaned afterthese two spills, as well as smaller spills and chronic oil pollu-tion, have allowed a detailed study of the short and long-termeffects of oiling and rehabilitation on the breeding productiv-ity of African Penguins.

Proportion of rehabilitated African Penguinsattempting to breed following the Apollo Seaoil spill

Six years after the Apollo Sea spill, approximately 60Vo of therehabilitated African Penguins that had been re-sighted in twointensively studied areas on Dassen Istand, had also been re-corded breeding. This figure is likely to be an underestimate, asit is impossible to capture every breeding attempt on the island.Furthermore, many of the birds re-sighted in these areas maymerely have been transient birds from other colonies. However,as can be seen in Figure 1, the proportion of the returned ApolloSea birds that attempted breeding over the six-year period issimilar for two different study areas. Both study areas were sam-pled intensively over the six-year period. Since the beginningof 1998 the proportion of returned birds attempting breeding hasremained fairly constant, and it is unlikely that this figure isgoing to increase further.

The fact that well over 607o of the rehabilitated penguins re-sighted in these study areas have attempted breeding bodesextremely well for the conservation of the species. However,there does appear to be a small proportion of rehabilitated birdsthat have not attempted to breed in the six years following theApollo Sea spill. The cause of this is unclear at present; possiblecauses include sub-lethal effects of the oil ingestion on thebirds' reproductive physiology and disruption of pair bonds andannual breeding cycles ofrehabilitated birds. This is an aspectthat requires urgent investigation, and will be the subject offuture studies.

Breeding productivity of Apollo Sea penguins

The effect of oiling and treatment (cleaning) on subsequentbreeding success was studied by comparing breeding para-meters of Apollo Sea nests (containing either one or two birdsrehabilitated following the Apollo Sea oil spill) and control nests(containing no oiled-rehabilitated birds; i.e. unaffected birds).Breeding success is naturally highly variable in African Pen-guins, so it is important that the nests being compared are moni-tored under the same conditions. In order to reduce failurethrough disturbance, and to maximise the number of nests moni-tored at the same time (to control for highly variable breedingsuccess), nests were selected during incubation rather than priorto egg-laying. A similar number of Apollo Sea and control nestswere monitored for each cohort. Between 1994 and2000, a totalof 17 cohorts of nests were monitored in which the followingparameters were compared:

tr Hatching success: proportion of chicks hatched from thenumber of eggs laid

tr Fledging success: number of chicks fledged as a proportionof the total number of chicks hatched; which together giverise to:

E Overall breeding success: probability ofan egg producinga fledged chick

Until January 2000, the reproductive success of 599 ApolloSea and 558 control nests had been monitored. The overallbreeding success for all Apollo Sea nests was 0.32 fledgedchicks per egg laid, compared to 0.30 for control pairs. Themean number of chicks fledged per pair for Apollo Sea birdswas therefore 0.62, whereas the mean number of chicks fledgedper pair for control nests was 0.58. There were no statisticattysignificant differences in breeding success between the twogroups for any of the studies. However, a closer inspection ofthe data reveals that in some of the study cohorts there are de-tectable differences between the two groups.

7A

OU

50

40\oo\

30

2A

10

20 Nel & Whittington (eds):

J Apallo Sea

U Control

Rehabilitation of oiled African Penguins

Figure 2. Fledging success ol Apollo Sea and Control birds at Dassen lsland, 1994-1 999.

90

BO

70

860a@8soofag4ao)!0lLL JU

2A

10

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The most noticeable differences in fledging success occurredin the first two years of the study (Figure 2). In the first studythat was conducted, in summer 1994, the fledging success ofchicks hatchedto Apollo Sea pairs was actually higher than thatof control pairs. This result is probably due to the Apollo Seabirds, which had just returned from being in captivity, beingmore habituated to and thus better able to cope with human dis-turbance than were the control birds. This would enable theApollo Sea birds to cope better with the researcher disturbanceresulting from the study than control birds. This conclusion issupported by a low-disturbance control study that was con-ducted at the same time, and showed that the researcher impactwas greater for the control birds than for the Apollo Sea birdsat this time. From the second year of the study, the frequencyof nest visits was reduced from daily visits to one visit every fivedays, in order to minimise this disturbance.

In a few of the other studies conducted during the first twoyears (Autumn 1995, Winter 1995 and Winter 1996) the ApolloSea pairs did substantially worse than control birds. In theautumn of 1995, there was a brief, two-week period of unusu-ally low food availability. This led to widespread and synchron-ised weight loss and mortality of chicks throughout DassenIsland. On average, chicks of pairs includin g Apollo Sea birdslost weight and died sooner than chicks of control pairs. Theother studies (Winter 1995 and Winter 1996) in which ApolloSea birds fared comparatively poorly were also conductedduring periods when breeding conditions were not favourable.Although both groups of birds had a relatively low fledging suc-cess in these studies, the Apollo Sea birds did notably worse.

These results therefore indicate that, when breeding condi-tions (especially feeding conditions) were average or good, theApollo Sea birds fared as well, and sometimes better than, con-trol birds. However, in studies conducted during periods of foodshortage or unfavourable breeding conditions the Apollo Seabirds were less successful at raising chicks than control birds.

In all studies after Winter 1996 there was no noticeable dif-ference between the fledging success ofApollo Sea andcontrol

birds. This indicates that the effects of oiling and rehabilitationon breeding success were short term in nature, being limited tothe first two years of the study. However, none of the studiesafter Winter 1996 were conducted during periods of significantfood shorlage. A real test of the long-term recovery of ApolloSea birds would be a future study conducted under poor feed-ing conditions.

Chick growth and survival

Another aspect which requires investigation is the quality (orviability) of chicks produced by Apollo Sea rehabllitated par-ents. The chick-rearing period is the most demanding period ofthe breeding cycle for the African Penguin. Chick growth is ameasurement that integrates aspects of foraging of both parents,and a detectable result at this level suggests underlying differ-ences in provisioning abilities (and therefore fitness) of one orboth parents.

Like most seabirds, African Penguins are long-lived andconsequently adjust their reproductive output to minimise therisk of adult mortality. By adjusting their investment in breed-ing activities (provisioning ofyoung) according to their condi-tion, adult birds can maximise the chances of surviving to breedat alater period, when conditions may be more favourable, orwhen the birds may be in a better condition. Reduced growthrates in the chicks of oiled birds have been reported in a numberof experimental studies, where birds have been dosed with6i19,10. 11" reduced growth rate observed in these studies wasthought to result from secondary poisoning of the embryo.However, other studies have shown that oil contamination canalso result in more indirect effects, including a disruption tonormal parental attendance and provisioning behaviours. Onewould therefore expect that the energetic demands of chick rear-ing would impose a greater energetic cost on oiled-rehabilitatedbirds if they were already energetically stressed owing to thecontamination.

The chick growth and survival data from the Apollo Sea

Wolfaardt & Nel: Breeding productivity and annual cycle of rehabilitated African Penguins

3000

2500

2000

1 500

1 000

5CI0

0

5 '10 15 2A 25 30 35 40 4s 50 55 60 65 70 75

Days after hatching

Figure 3. Mean growth curve for all nests monitored during 1994/95 versus the mean growth curve for Apotto Sea and Control birds forstudy 2, Autumn 1995.

m(n(sE

study tell a very similar story to that of the breeding successdata. Detectable differences in chick growth rates were foundin only two studies and these were in the early part of theproject. During periods ofpoor food availability, when chicksin both groups showed depressed growth rates, chicks fromApollo Sea rehabilitated birds were more adversely affected(Figure 3). In all studies after Winter 1996 in which chicks wereweighed, the growth rates of chicks from the two groups weresimilar. Overall, there were no detectable differences in the

growth rates and fledging masses of chicks from rehabilitatedand unaffected birds (Figure 4).

These results indicate that when the birds are already physio-logically stressed owing to poor resource availability (typicallya shortage of prey), the extra energetic demands of chick rear-ing impact the rehabilitated birds more than control birds. How-ever, these effects appear to be relatively short term in naturefor African Penguins, not persisting beyond the second yearafter the oil spill.

2000

1 500

1 000

500

0

Days after hatching

Figure 4. Mean growth in body mass of chicks from Apollo Sea and Control group nests, Summer 1gg4lg,.

o)6

o

'-|-- Apollo Sett

-o- Control

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73

21

100

Nel & Whittington (eds): Rehabilitation of oiled African Penguins

Figure 5. Comparison of moult cycles of Apollo Sea and Control group birds for the period December 1994-June 2000.

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Effects of removing birds from colonies forcleaning and treatment

Although the aim of SANCCOB is to clean, treat and releaseoiled birds as quickly as possible, during large oil spills involv-ing thousands of penguins (such as the Apollo Sea and Treas-ure spllls), it may take up to three months to process the bulkof the birds. Apart from the potential health risks of keepinglarge numbers of birds in captivity for this length of time (such

as the contraction of avian diseases), removing oiled birds fromthe wild may have further impacts, including the disruption ofbreeding and moult cycles, as well as established pair bonds.

During the first two years following the Apollo Sea spill, themoult cycle of rehabilitated birds was not synchronised with therest of the population at Dassen Island, but became more syn-chronous thereafter (Figure 5).

Similarly, the breeding cycle was also slightly disrupted inthe period immediately after the release of birds. However, thiswas not as significantly impacted as the moult cycle and wasmostly due to many Apollo Sea birds only attempting to breedfor the first time during the second year following the oil spill(Figure 6).

Penguins, like most seabirds, tend to establish long-term pairbonds. Breeding success is generally greater in well-established

pairs than it is in recently formed pairsl1,tz,t:. Under normalconditions, between 807o and 94Vo of African Penguins willmate with the same paftner in the following yearl4'ts. However,only 67Vo of Apollo Sea rehabilitated penguins retained thesame mate in subsequent breeding attempts. The lower matefidelity in Apollo Sea penguins may be due to the death or pro-longed absence of breeding paftners during the oil spill. How-ever, even where both partners survive an oil spill, they may be

unable to re-unite owing to subsequent asynchrony in theirannual moult cycles. This may arise due to differences in thetime spent in captivity (and away from the breeding colony) orthe amount of time required before the birds are physiologicallyable to breed again.

Temporary relocation of clean penguins as anew management tool

Prior to the Treasure oil spill, rescue attempts had focused onlyon oiled penguins. However, owing to the severity of the Treas-ure o7l spill and the likelihood of unmanageable numbers ofpenguins becoming contaminated, approximately 1 9,500 cleanpenguins were evacuated from Robben and Dassen islands, toprevent them from coming into contact with the oil. These"clean" penguins were transported 800 km to Cape Recife in the

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22

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Wolfaardt & Nel: Breeding productivity and annual cycle of rehabilitated African Penguins 2g

Table 1 . Comparison of the numbers of oiled-rehabilitated and relocated (unoiled) birds observed back and breeding on Dassen lslandafter the Treasure oil spill.

Oiled penguins thatwere rehabilitated

Un-oiled penguins Level ofthat were relocated significance P ff)

Nurnbcr of birds renroved flom Dassen Island

Nunrbcr of bilds observed on Dassen Island b_v

Nurnbcr of birds brcccling on l)assen Islancl b1,

l7 April 2002

l7 April 2002

2,144

2,055 (ts%)

451 (11Eo)

1. 130

698 (62Eo)

161 (41a/a)

<0.0001

<0.0001

Eastern Cape, where they were released. This was the first timethat such an operation had been undertaken for African Pen-guins.

The return of three relocated penguins to their breeding col-onies was monitored by means of satetlite transmitters. Inaddition, over a thousand relocated birds were marked withidentifiable flipper bands. Relocated birds started ar:riving backat Dassen Island a mere 11 days after they were released at CapeRecife, while the bulk probably arrived about a week later.

When comparing data for the relocated and rehabilitatedpenguins from the Treasure spill, it is clear that the most notice-able difference lies in the proportion of returned birds that havebeen recorded breeding (Table 1). The much higher proportionof relocated penguins having attempted breeding is likely toresult from a number of factors. Firstly, the relocated birds were,on average, away from the island for a much shorter period oftime than oiled-rehabilitated birds. This would result in lessdisruption to breeding and moult cycles, and to pair bonds.Secondly, the relocated birds did not suffer any of the poten-tially harmful physiological effects of oiling. Another factor rhatmay have influenced these results is the fact that relocated birdswere collected from specific parts of Dassen Island, whereasoiled birds were collected from a much wider area. This in-creases the probability ofre-sighting relocated birds and there-fore biases the comparison slightly. However, it is clear thatrelocation of penguins during a large oil spilt is an importantproactive management tool.

Conclusion

This study proves conclusively that African Penguins can besuccessfully rehabilitated after oil contamination, and that themajority of rehabilitated birds become fully restored back intothe active breeding population. Overall, no difference wasdetected between the breeding performance of rehabilitatedbirds and unaffected birds. However, this study did detect somesubtle impacts of oiling and rehabilitation. These ranged fromaltered annual cycles ofrehabilitated birds to lowered breedingperformance of rehabilitated birds during periods when feedingconditions were poor. These effects appear to be restricted to thefirst couple of years following an oil spitl, indicating that theyare short term in nature, and that the penguins do recover fromthem. There is, however, some concern about a minority of birdsthat have been re-sighted alive and in apparent healthy condi-tion, but have not as yet been recorded breeding. This phenom-enon will be the subject of further investigation.

All in all, the rehabilitation of African Penguins after theApollo Sea oil spill appears to have been a resounding success.The results show that rehabilitation is not only effective at theindividual level but also at the population level. Several factorslead to high rehabilitation and restoration rates for African Pen-guins. These include the body size and robust nature of the bird,the close proximity of most colonies to rehabilitation or stabilis-

ation/initial holding centres, the world-class facilities and exper-tise available at SANCCOB and the ease with which the pen-guins can be monitored after they have been released. Rehabili-tation of oiled African Penguins is thus an invaluable tool forthe management of this threatened species.

Although African Penguins can be successfully rehabilitated,prevention of oil contamination in the first place is clearly moreadvantageous. Temporarily relocating clean penguins during alarge oil spill appears to be very successful in that it preventsbirds from becoming contaminated and minimises the disrup-tion to breeding and moulting activities, by reducing the amountof time the affected penguins spend away from the colony.Results from the Treasure oil spill show very clearly that re-located penguins return to breed more readily than oiled-rehabilitated penguins. This again highlights the fact that avoid-ance of oil spillage altogether is the best solution. Furthermore,it is far more cost-effective to relocate birds than to wait for themto become oiled. However, relocation can only be used for verylarge oil spills and normally only after alarge number of birdshave already become oiled. Most oil spills along the southernAfrican coast are actually first detected by the sight of oiledpenguins arriving on landing beaches of their breeding colonies.The extent and movement of the spill is normally only estab-lished after this, thus allowing an informed decision to be madeon relocating clean birds. Furthermore, the origin of mostsmaller spills is hardly ever established. Relocation will thusnever replace the need for an effective rehabilitation facilitycapable of handling tens of thousands of penguins. Relocationshould rather be seen as an additional and extremely valuablemeasure for minimising the number of penguins that becomeoiled, given the appropriate conditions.

References

1. Newman, S.H. 1996. The controversies surrounding oiledwildlife rehabilitation. In: Rineer-Garber, C. (ed.), Proceed-ings 4th International Conference on the Effects of Oil onWildlife. International Bird Rescue Research Centre,Berkely, California. pp. 146-152.

2. Fowler, G.S., Wingfield, J.C. & Boersma, P.D. 1995. Hor-monal and reproductive effects oflow levels ofpetroleumfouling in Magellanic Penguins (Sphenis cus magellanicus).Auk ll2: 82-389.

3. Grau, C.R., Roudybush, T., Dobbs, J. & Wathen, J. 1977.Altered yolk structure and reduced hatchability of eggsfrom birds fed single doses ofpetroleum oils. Science 195:779-181.

4. Cavanaagh, K.P., Goldsmith, A.R., Holmes, W.N. &Follet, B.K. 1983. Effects of ingested petroleum on theplasma prolactin levels during incubation and on the breed-ing success of paired mallard dtcks. Archives of Environ-mental Contamination and Toxicology 12: 335-341.

5. Leighton, F.A. 1991. The toxicity of petroleum oils to

24 Nel & Whittington (eds): Rehabilitation of oiled African Penguins

birds: an overview. In: White, J. & Frink, L. (eds), TheEffects of Oil on Wildlife: Research, Rehabilitation and Gen-eral Concerns, Sheridan Press, Hanover, PA. pp. 43-57.Briggs, K.T., Yoshida, S.H. & Gershwin, M.E. 1996. Theinfluence of petrochemicals and stress on the immunesystem of seabirds. Regulatory toxicology and pharmacol-ogy 23: 145-155.Trivelpiece, W., Butler, R.G., Miller, D.S. & Peakall, D.B.1984. Reduced survival ofchicks ofoil-dosed adult Leach'sStorm-petrels. Condor 86: 81-82.Eppley, Z.A. & Rubega, M.A. 1990. Indirect effects of an

oil spill: reproductive failure in a population of South Polarskuas following the "Bahia Paraiso" oil spill in Antarctica.Marine Ecology Progress Series 67: l-6.Peakall, D.B., Hallett, D., Miller, D.S., Butler, R.G. &Kinter, W.B. 1980. Effects of ingested crude oil on B1ackGuillemots: a combined field and laboratory stldy. Ambio9:28-30.Miller, D.S., Peakall, D.B. & Kinter, W.B. 1978. Ingestion

ofcrude oil: sublethal effects in herring gull chicks. Science

199 315-317.Richdale, L.E. 1957. A population study of penguins.Oxford University Press, Cambridge.Wood, R.C. 1971. Population dynamics of breeding SouthPolar Skuas ofunknown age. Auk 88: 805-814.Mills, J.A. 1973.The influence of age and pair bond on thebreeding ecology of the Red-billed Gull, Larus novae-hollandiae scopulinus. Jourual of Animal Ecology 42:141-t62.Randall, R.M. 1989. Jackass Penguin. In: Payne, A.I.L. &Crawford, R.J.M. (eds), Oceans of life off southern Africa,Vlaeberg Publishers, Cape Town. pp.244-256.Crawford, R.J.M., Boonstra, H.G. v. D., Dyer, B.M. &Upfold, L. 1995. Recolonisation of Robben Island byAfrican Penguins, 1983-1992.In: Dann, P., Norman, L &Reilly, P. (eds), The Penguins: ecology and management.Surrey Beatty and Sons, Chipping Norton, Australia.pp.333-363.

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Estimating the demographic benefits of rehabilitating oiledAfrican Penguins

PETER G. RYAN

Percy FitzPatrick lnstitute, Universitlr of cape Town, Rondebosch, 7701, south Africa,e-m ai I : p ryan @ botzoo. uct. ac. za

Abstract

Ryan, P.G. 2003. Estimating the demographic benefits of rehabilitating oiled African Penguins. In: Nel, D.C.& Whittington, P.A. (eds), Rehabilitation of oiled African Penguins: a conseryation success sto:. BirdLifeSouth Africa and the Avian Demography Unit, cape Town, South Africa. pp.25-29.

A simple, deterministic population model was used to estimate the difference rehabilitating oiled African pen-gins Spheniscus demersus has made to the current penguin population. The model was parameterized to showthe same long-term decrease in African Penguins as that observed since the mid-l950s (approximately -l.5Voper year). Using the actual numbers of oiled penguins released from SANCCOB since 1968, the model sug-gests that SANCCOB's effotts have resulted in the cunent (2002) African Penguin population being lg%olarger(163,000 adults) than it would have been in the absence of rehabilitation efforrs (137,000). Most of the ben-efits of rehabilitating penguins have occurred since 1994, when there have been two major oiling events, andnumerous smaller spiIls. The estimated benefit to date excludes the almost 20,000 penguins that weretranslocated to avoid being oiled during the Treasure spill in 2000, as well as the benefits from treating non-oiled birds brought to SANCCOB.

The potential future cost of no longer rehabilitating oiled birds was estimated using the stochastic, individual-based model Vonrnx (Lacy 1993). Even without catastrophic oil spills, rehabilitating birds from chronic oil-ing will result in 5Vo more penguins over 20 years. Assuming catastrophic spills l,:tll lOTo of the population,the average population size after 20 years ranges from22-617o greater if oiled birds are rehabilitated as theprobability of spills increases from5-2\Vo per yea.r. The results suggest that, although the demographic impactsof rehabilitating oiled penguins were initially modest, this activity is becoming increasingly important forconserving African Penguins.

lntroduction

The African Penguin Spheniscus demersus is listed as Vul-nerable due to its continued population decreasel. After fallingto roughly a quarter of its original population size during thefirst part of the 20th century owing to direct exploitation, Afri-can Penguin numbers continued to decrease by approximatelyl.5Vo per year over the last 50 years (excluding the apparentrecent increase in the South African population thought to be theresult of improved prey availability2). Currently, the main fac-tors driving this decrease are thought to be competition withcommercial fisheries for prey species, increasing predation byCape Fur Seals Arctocephalus pusillus, competition with furseals for space at breeding islands, degradation of breedingcolonies caused by guano collection, and mortality due to oil-ing3. The rate of oiling has increased dramatically over the lastdecade, from an average of 0.2Vo of the population oiled eachyear in the 1970s and 1980s4 to more than2Vo per annum in the1990s. Even excluding the catastrophic spills that occurred fol-lowing the sinking of the Apollo Sea in 1994 and Treasure in2000, the average oiling rate for the 1990s was more thandouble that in previous decades (0.5Vo of the population eachyear).

One way to reduce the population decrease of African pen-guins is to rehabilitate oiled birds. Cleaning oiled birds com-menced in 1963, but only stafted on alarge scale in 1968 afterthe Esso Essen ran aground, oiling some 3,000 birdss. Of 1,700birds collected and cleaned, 400 survived and were released.This incident led to the formation of the Southern African Foun-dation for the Conservation of Coastal Birds (SANCCOB).Between 1968 and 2001 SANCCOB has admitted more than48,000 oiled penguins. The average release rate of oiled Afri-can Penguins (7 47o overall) has increased over time from 55Voin the 1970s, to 677o in the 1980s, l67o in rhe 1990s, andS6Vosince 2000. This increase reflects increasing expertise in thehandling of oiled birds. Unlike rehabilitation programmes else-where6, rehabilitated African Penguins have a high survivalrate7, indistinguishable from non-oiled birds8,e. They also ex-hibit similar breeding success to control birds1o, and thus reha-bilitation of oiled birds potentially plays an important role in theconservation of African Penguins. Here I estimate the impactSANCCOB has made to the current population of African Pen-guins, and then explore the potential future benefits of maintain-ing the infrastructure and expertise necessary to treat oiled pen-guins, especially following a catastrophic spill that affects asignificant proportion of the penguin population.

25

Nel & Whittington (eds): Rehabilitation of oiled African Penguins

Suryivaljuveuile (0 1 ycars)

immaturc ( 1 -2 years )

adult (>2 1,ears)Maxinrum age

ReproductionFleclglings.pair r.year I

Proportion of birds breeding2 years

3 leals'1 Ycars2 5 years

Table 1. Demographic parameters used to model the population ofAf rican Penguins (f rom Whittington et al.2OOO). Variance estimatesare given for parameters that were varied in Vonrex.

Parameter Mean SD

300,000 adults in the mid-1950s, 220,000 in the late 1970s,194,000 in the late 1980s, and 178,000 in the early 1990s11.

This could be closely approximated with a model that had a

constant growth rate of -l.35Vo per yea"r. The model was initi-ated with the population close to stable age distribution, andwith a population of 300,000 adults (i.e. in adult plumage,>1 year old) in 1956. At stable age distribution, adults make up78Vo ofthe total population. Projecting forward, it suggests thatthe penguin population in2002 is around 163,000 adults (totalpopulation of 203,000 birds), which is perhaps slightly less thanthe 2001 population estimate, but greater than the 1998 esti-mate2.

The recent population trend of penguins incorporates theeffects ofcleaning oiled birds since the 1960s, and thus rehab-ilitation benefits are implicitly included in the standard penguinmodel. To estimate what the current population would havebeen were there no rehabilitation, the numbers of oiled birdscleaned and released by SANCCOB each year were removedfrom the model. Birds were removed from each age class as a

function of the proportion of each age class in the entire popu-lation. This assumes that rehabilitated birds are a random sam-ple of the population, and is supported by the observed closeagreement between the proportions of rehabilitated juvenilepenguins (227o, SANCCOB unpubl. data) and their proportionin the model population (21%).

At first rehabilitation efforts had a trivial impact on the popu-

lation of African Penguins (Figure 1). It took almost 20 years

before cleaning oiled birds resulted in a 27o larger penguinpopulation, and it was only after the Apollo Sea spill in 1994that the impact exceeded the 57o mark. However, rehabilitationmade a significant contribution after the disastrous Treasurespill in 2000. By 2002, the African Penguin population wasl9Vo larger (33,000 birds) than if cleaning had not taken place

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Assessing the impacts of cleaning oiled birdsto date

The past contribution of rehabilitating oiled birds was esti-mated using a simple, deterministic, age-sttuctured model of theAfrican Penguin population. The model assumed a constantgrowth rate with no density dependence. Survival and fecunditypa-rameters (Table 1) were taken from the range of best estimatesused in the Population and Habitat Viability Assessment(PHVA) conducted for African Penguins3. The parameterschosen were selected to mimic the observed rate of populationdecrease estimated for the entire African Penguin population:

400000

350000

300000

250000

200000

1 50000

1 00000

50000

\\ -\\

Adults

Treasure

1 960 1970 1 980 1990 2000

Figure 1 . Trends in the population of Af rican Penguins over the last 50 years. Solid Iines track the observed population trend and dashed

lines show the projected population trend in the absence of rehabilitation by SANCCOB since 1968.

SANCCOBopens

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Sea

population

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Ryan: Demographic benefits of rehabilitating oiled African Penguins

since 1968. This excludes the benefits of translocating almost20,000 birds to prevent them getting oiled during the TreasurespiIl. The translocation was effective thanks to handling skillslearned by SANCCOB, coupled with the disaster managementplans put in place after many birds died during initial transpoftto the rehabilitation centre during the Apollo Sea spill rn 1994.The estimate of SANCCOB's contribution to date also fails toconsider the contribution of non-oiled birds treated bySANCCOB; these birds were excluded because their survivaland reproductive output following treatment have not beendetermined.

Estimating the benefits of continued rehabili-tation

The individual-based, stochastic Population Viability Assess-ment (PVA) model Vonrnxl2 was used to estimate the potentialbenefits of continued cleaning of oiled penguins. VonrBx is themodel that was used to conduct the PHVA of African Penguins3,and for this simulation it was set up in a similar way as for theAfrican Penguin PHVA (a single population, starting at stableage distribution; no density dependence; no inbreeding depres-sion, etc.). The same demographic parameters were used as inthe deterministic model, with the addition of some variancearound parameter values (Table 1). The model cannot accom-modate the full penguin population, so it was run with a start-ing population of 10,000 birds. This was then rescaled to givea starting population of 163,000 adult birds (rotal 203,000), rhepopulation predicted for 2002. Simple scaling of effects ispotentially misleading, because stochastic effects are greater insmall populations, but the model starting population was suf-ficiently large to avoid significant impacts from demographicstochasticity.

The model was used to estimate the impacts of two types ofoiling: catastrophic spills and low-level, chronic oiling. Cata-strophic spills are spills that typically occur close to breedingcolonies and affect large numbers of birds. To date the worstspill resulted from the sinking of the bulk canier Treasure inJune 2000, which threatened more than2\Vo of the global popu-lation of African Penguins. This was perhaps an extreme spill,because it affected birds at two of the largest colonies (Dassenand Robben islands). For the model projection, a catastrophic

spill was assumed to reduce survival and reproduction of theentire population by either 10Vo (roughly equivalent to oiling107o of birds) or 5Vo.For the simulations where cleaning oiledbirds continued, it was assumed that 80Va of oiled birds werereleased back into the population. This is slightly less than thesuccess rate recorded since 2000 (867o),bltrehabilitated birdsmay not perform quite as well as control birds13,10. The impactof a catastrophic spill on reproduction was assumed to be un-affected by rehabilitation, because affected birds are unlikely tobreed successfulty in the year of the spiI110. Because cata-strophic spills are unpredictable, they were modelled as stoch-astic events, with the probability of a catastrophic spill occur-ring in any given year ranging from0-20Va. For each scenariothe model was nrn 200 times, allowing the estimate of averagepopulation performance as well as the range of possible out-comes.

Chronic oiling results from small spills, often of unknownorigin, that affect relatively few birds (typically <1000 individu-als). The numbers of birds affected by chronic oiling was esti-mated as the residual number of birds admitted to SANCCOBonce catastrophic spills were excluded. Overall this has aver-aged 600 birds per year, but the numbers have increased overtime, and since 1990 the average has been 925 birds per yeat'.In the model, chronic oiling was simulated by removing 46 birdsper year from the starting population of 10,000 (equivalent to920 birds per year from the global starting population of ap-proximately 200,000 penguins). With rehabilitation, the lossesdue to chronic oiling were cut to only 8 birds (equivalent to 160birds per year). Shannon & Crawfordla raised concerns aboutthe impact on penguin reproduction that could result frompatrolling colonies for oiled birds. This effect was not incorpo-rated in the model, because of uncertainty about the levels ofdisturbance (most colonies are not patrolled regularly, and mostchronic oiling still occurs as discrete events).

Clearly predicting future population trends is fraught withdifficulty, and requires often unreasonable assumptions. How-ever, the model can be used sensibly to assess the contributionmade by rehabilitation efforts by comparing outcomes with andwithout cleaning of oiled penguins"r' 15. Even without any cata-strophic spills, rehabilitating birds affected by chronic oilingresults on average in a 77o larger population after 20 years(Table2; Figure 2). Witha5To probability of acatastrophic spill

Table 2. Projected population growth rates (%) and mean population sizes of adult Af rican Penguins alte( 20 years given different prob-abilities and severities of catastrophic oil spills. The benefit of continued rehabilitation is the % increase in the mean projected populationresulting from cleaning of oiled birds.

Probability ofcatastrophic spills With rehabilitation

BenefitNo rehabilitation

SDSD Nro r""r" Nro r"rr"

No catastrophes

Severity of catastrophe 10olo

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Scverity of catastrophe 57r5a/,:

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99,00094.000E9.00082,000

14

lu2433

28 Nel & Whittington (eds): Rehabilitation of oiled African Penguins

1 40000

1 20000

1 00000

80000

60000

40000

20000

0

-+_

each year, the penguin population averages 22Tolarger after 20years for "bad" spills (ll7o impact) or l4%o larger for less severe

catastrophes (57o impact). The benefit of continued rehabilita-tion of oiled birds increases rapidly with increasing probabilityof catastrophic spills, averaging 29Vo, 44Vo and 6l% larger as

the risk of "bad" spills increases from l\Vo to l57o and20Va(Table 2; Figure 2).

In general, the severity of impact of individual catastrophicspills and their frequericy have roughly equal impacts on theprojected penguin population size after 20 years (i.e. a 57o

annual spill risk affecting 57o of the population has a similarimpact to a2.5 Vo anntal spill risk affecting ll%o of the popu-lation; Table 2). Rehabilitating oiled birds greatly reduces theimpacts of oiling, with the predicted population after 20 years

being little influenced by the frequency of catastrophic spills(Table 2). The range of possible outcomes varied greatly (Fig-ure 2), but annual average growth rates were more variablewhen there was no rehabilitation, and variability increased withincreasing risk of catastrophic spills (Table 2).

Conclusions

These results suggest that although the initial benefits of clean-ing oiled penguins were largely triviall6, rehabilitation has be-come increasingly important for the conservation of AfricanPenguins. Already rehabilitation has resulted in the currentpopulation being approximately l9Vo larger than it would havebeen had there been no attempt to rehabilitate oiled birds. Pre-dicting the future value of rehabilitating birds depends on thefrequency of major and minor oil spills. If conditions experi-

aL(sooN.=U).E=(r)CC)o-==E(d

oLo-oE=CEooo'dL

o_

Cleaning

Nocleaning

enced during the last decade continue, when there were twocatastrophic spills and numerous smaller spills, it is clear thatthe penguin population will decrease much more rapidly in theabsence of a professional rehabilitation programme. Althoughmost of the risk is associated with catastrophic spills, we can-not afford to act only when catastrophes occur, because chronicoiling also makes. a significant impact on penguin populations,and because much of the success of cleaning efforts to date re-sults from the maintenance of a dedicated, well-trained rehabili-tation team that can act swiftly when catastrophes occur.

Acknowledgements

This exercise was initially conducted by the 2002103 class ofconservation biology masters students at the University of CapeTown. I am grateful for their input to the development of themodels.

References

l. Birdlife International 2000. Threatened Birds of theWorld. Lynx Edicions and Birdlife International, Barce-lona and Cambridge, UK. 851 pp.

2. Crawford, R.J.M., K1ages, N.T.W. & Wolfaardt, A.C. 2001.South Africa's penguins on the rebound! www.uct.ac.zaldepts/stats/adu/species/sp003_09.htm

3. Whittington, P.A., Crawford, R.J.M., Huyser, O., Oschad-leus, D., Randall, R., Ryan, P., Shannon, L.V., Wolfaardt,A., Cooper, J.,Lacy, R.C. & E11is, S. (eds). 2000. AfricanPenguin population and habitat viability assessment.

201510

Probability of catastrophic oil spills (% per yeafl

Figure 2. The population of African Penguins projected by Vonrex after 20 years (2022) as a function of the annual probability of catastrophicoil spills (assuming each spill affects 10% of the population). Two scenarios are compared: one where current cleaning efforts are maintained("cleaning" = solid lines), and one where rehabilitation ceases ("no cleaning" = dashed lines). Vertical bars show the 95% confidence interval

around the mean population projection (n=200 iterations).

Ryan: Demographic benefits of rehabilitating oiled African Penguins ,o

4.

5.

6.

7.

IUCN/SSC Conservation Bleeding Specialist Group. AppleVa1ley. MN.Adams, N.J. 1994. Patterns and impacts of oiling of Afri-can Penguins STtheniscus demer,sus'. 1981 1991r. Biol.()ctnserv. 68: 35 41.Nel, D.C., Clawfbrd, R.J.M & Parsons. N. 2003. The con-selvation status and impact of oiling on the Aft'ican Pen-guin. In: Nel, D.C. & Whittington, P.A. (eds), RehabilitcL-tiott of oiled Af rican Pertgttitt.s: Lt ( t,ns('t'vdtion .tuccesssror_r'. BirdLif-e South Afiica and the Avian DemographyUnit. Capc Town. South Africa. pp. I 7.Sharp. B.E. 1996. Post-release survival of oiled, cleanedseabirds in North America. lDls 138: 222 228.Randall. R.M.. Randall, B.M. & Bevan, J. 1980. Oil pol-lution and pcnguins is cleaning.justificd'? Mar. Pollut.Bull. 1l 234 231.Undelhill, L.G., Bartlett, P.A., Baun.rann, L., Crawl'ord,R.J.M., Dyer, B.M., Gildenhuys, A., Nel, D.C., Oatley,T.B., Thornton, M.. Upfold, L.. Williams. A.J., Whitting-ton, P.A. & Wolfa:rrdt, A.C. 1999. Mortality ancl sur:vivalof Afiican Penguins Sphenisctrs denter,sus involved in theApollo Sett oil spill; an evaluation o1'rehabilitation ef1brts.Ibis 141 29 31.Whittington, P.A. 2003. Post-release survival of rehabllitatedAtiiciin Penguins. In: Nel. D.C. & Whittington, P.A. (eds),R e h tfi i I i t ctt i o n rtf o i I e d A.fi' ic o t t. P e n g tLi tt s ; a c o n.t L' rt' Ltt i o t t

sr.rcess sron'. Birdl-ife South Africa and the Avian Demo-graphy Unit, Cape Town, South Africa. pp. 8 10, l5-17.

10. Wolfaardt, A.C. & Nel, D.C. 2003. The impact of oil pol-lution and rehabilitation on the breeding productivity andannual breeding and moult cycles ofAfrican Penguins. In:Nel, D.C. & Whittington, P.A. (eds), Rehabilitation of oiledAfrican Penguins: a conservation success story. BirdLifeSouth Africa and the Avian Demography Unit, Cape Town,South Africa. pp. 18-24.

11. Crawford, R.J.M., Williams, A.J., Hofmeyr, J.H., Klages,N.T.W., Randall, R.M., Cooper, J., Dyer, B.M. & Chesse-let, Y. 1995. Trends of African Penguin Spheniscus de-mersus populations in the 20th century. S. Afr. J. Mar. Sci.16:101-118.

12. Lacy, R.C. 1993. Vortex: a computer simulation model forPopulation Viability Analysis. Wildl. Res.20: 45-65.

13. Whittington, P.A. 1999. The contribution made by clean-ing oiled African Penguins Spheniscus demersws to popu-Iation dynamics and conservation of the species. Mar. Orn.27:177-180.

14. Shannon, L.J. & Crawford, R.J.M. 1999.Management ofthe African Penguin Spheniscus demersus - insights frommodelling. Man Orn.27: ll9-128.

15. Bessinger, S.R. & Westphal, M.L 1998. On the use ofdemographic models of population viability in endangeredspecies management. J. Wildl. Manage. 62: 821-841.

16. Frost, P.G.H., Siegfried, W.R. & Cooper, J.1976. Conser-vation of the Jackass Penguin Spheniscus demersus L. Biol.Conserv. 9:79-99.

9.

Are African Penguins tough enough? A perspective on the rehabilitationof oiled birds

LES G. UNDERHILL

Avian Demography Unit, Department of Statistical Sciences, University of Cape Town,Rondebosch, 7701, South Africa, e-mail: lgu @ adu.uct.ac.za

Abstract

Unclerhill. L.G. 2003. Arc Afiican Penguins tough enough? A perspectivc on the rehabilitation of oiled birds.In: Nel, D.C. & Whittington, P.A. (eds). Rehabil.ittttion of oiled A.frican Penguins: Lt consertutictn.vut:ce,ss stor\t.

Bircllif'e Soutl.r Al'rica arrd the Avian Demography Unit, Capc Towrr, South Africa. pp. 30-3 l.

Penguins are inrprcssivcly tough animals. a quality that enables thcm to be cleaned when they becornc oilcd.However. in order to be successlul, the cleaning operation has to be mobilised rapidly. For this reason,

SANCCOB needs to be rnaintained in a state of readiness fbr action continuously. Since the Treosure oil spillincident of 2000, SANCCOB has restructured institutionally and has adopted a strategy of long-ternrsustainability.

Onc clcar message has come through the previous prpers.Afl'ican Penguins are tough. Tough, yet vuh.rerable.

Anyone who has handled penguins will be aware that theyf'eel more like seals than bilds. It is this toughncss. above all. thatmakes it possible for us to clcan them wl'ren they are oiled.When "normal" l1ying bilds. such as cormorants ancl -9ulls. getoiled, it is extremely difl'icult to clean thern. Compaled to pen-guins. these species ale delicate and dainty, and are not easilycaught until they are really weak. Thc fact tl'rat we do so wellat cleaning penguins in South Africa is sorlething we can be

parlicularly proud of - but we also need to share this pride withthe bcast wc are dealing withl

Bccause penguins ale tough, they are cleanable. But beingcleanable cloes not ensure that they get cleaned. To gct therrcleaned. a whole chain ofplocedures needs to be in place. Everylink in the chain is irnportant.

Oil has two dramatic ettbcts on penguins. On the outside, itruins tl're insulation, and allows tl-re cold Benguela water to reach

the skin and sr-rck the heat out ol'the pengr-rin's body. On theinside, oil ingestecl cluring preening causes the bird to suffbrllorn petrochernical poisonin-g, an even greater threat. In spiteof this, the penguin is probably tough enough to swim ashoreand hardy enough to survive a f'ew days on the shoreline. Butthat is wl'rere its tor-rghness ends. Unless rescued, it will die. Itcannot de oil itsell'.

Success at war is a conseLluence of prepaledness in tirncs ofpeace. SANCCOB has been to the battlefleld twice in the past

l0 years. ln 19921, when thc Apollo Sea s:rnk, 10,0(X) penguinswere oiled. We suffer:cd 5.000 casualties. with 50% of our"sailors" dying. In 2000, when the Treusure sank, our casualtyratc was only 107o, in spite o[having twice as many "sailols"in the battle. War fbr SANCCOB aLrives as suddenly as 1 1 Sep-

tember 2001 arlived for the Worlcl Trzrde Center in New York.The clouds of wal do not gather on the horizon fbr SANCCOBfol months, allowing us the opportunity to beef up our plans.One rnorning we wake up, and discover that there are thousandsof oiled pengr-rins on our beaches. On that day. wc need to be

ready.

Would you fly out of an airpolt that claims that flying is nowso saf'e that they can dispense with their ernergency services'lAlthough every aspect of air safety is continuously beingin.rproved, airport disasters still stlike.

Likewise, although we can do all in our power to reducc thenumber of oil spills, we cannot prevent them entirely. It is im-portant that we continue and redouble our efforts to prevent oi1

entering the sea in the lirst placc. We need to :rddress the twinoil problen'rs:

l. The ongoing, almost continuous, small oil spills, which are

caused by carelessness and wilful purnping of bilge waterand ballast water exchange. Thesc send a regular stream ofoiled penguins to SANCCOB.

2. The spills involving lalge numbers of penguins c:u-rsec1 byheadline-grabbing disastels. such as the ApolLo Sea spill ol1994 and rhe Treusure spill of 2000.

Ships do need to be built n'rore saf'ely and ilesigned so thatthey ale lcss likely to release oil when they sink. Thcy do need

to be inspected more regularly ancl more rigorously. Regulationsabout bilge purnping do need to be more strictly enfblced and

ports need to make bettcl and mote convenient provision foracceptiug these pollutants and dealing with thern. Procedures forhandling crippled ships. which use Cape Town as "polt oflefuge" and which are likely to become oil pollution risks, donecd to be reconsidered. At a more esoteric level, Table Baycould be given some ltrrm of "special pen-uuin area" status, witl.tregulations clesigned firstly to reduce the risk of penguins beingoiled in these busy shipping lanes, ancl secondly to reduce thcrisk of oil reaching Robben Island, which now hosts the world'sthird largest Afl'ican Per.rguin colony.

But it is also critical to rnaintain a balance. We need to re-member that oiling is only one of a battery of problems lacingthe Afi'ican Penguin at the start of the 2l st century. We nccd tcr

bear in mind that during the periocl l'rom rbout 1980 to 1994,

when there were very f'ew oil spills, we u'ele still losing pen-

30

Underhill: Are African Penguins tough enough? 31

guins at a downwards trend of about 2% pcr year. Most ol'tl-relactors which caused tl'rc ongoing deciine are poorly Llnderstoo.l.They include thinss such as interactions with thc fishery. Howmuch tlsh must we leave in the sea so that penguins (and otherseabirds) hat,e "enough"l Is it sensiblc to creatc "non-fishingzones" around breeding islands l Cape Ful Seals. rrostly youngmalcs. are known to kill substantial nuntbers o1 penuuins. Butwe do not reallv undelstand the extent of thc ploblent, or if itis a clitical tactor. It is clear that All'ican Penguins face mrnythreats, lnost of whicl'r are cornplex ancl c'litficult to mitigate.Howcver. the previor-rs papers have shown that cte-oiling and re-habilitating oilecl penguins. although treating the syrnptomrather than the causc. is a way in which we can cf ctively alle-viate somc of the irnntediate presslrre on this vulnerable spccies.Il rve do not treat oilecl birds. we rnay lose a large proportion ofthe population before we are able to el'ltctively mitigate thenran) lll|cat\ lhlrt llrce thi: :peeic:.

Although SANCCOB has bcen in existence fbr: sor.ne 3zlyears. it is clcar that its role and responsibility changed radicallydurin-s the last decacle. witl.r rnore lhan J5al: o1'all Afi-ican Pen-guin oilings occulring during this time. SANCCOB needed toadapt. and corrsequently was restructurecl during 200 l.Itchanged liorn being an NGO (non-eoternmcntal organisation)and becarne a Section 21 Company with a boarcl of directors.none of wl'rom ale paid. The boald is responsible for the over-all policy of SANCCOB. Day to-day operations are cr-rr.rrrollcclby a chief execr-rtive officer. One of the boar-cl's chiel- objectivesis to mastermind the long,tcnn sustainabilitv of the oper-atirtn.The board currently has two ma.jor concerns: flnance and loca-tion.

One of thc earlv clecisions that the board hacl to take was toachieve a closcl rlatch between income and expenditure. Thcalternative was a gradual running down of reser\res and inevi-table closr-rre. Achieving this rnatch necessitated a nra.iot. l.estruc-turing of the staff cornplement and resulted in sever-al redundln-cies. The hard chrlice was therefbre betwcen a rnec'lium-sizedoperation, which was not sustainable in the long ter-m. and a tinyoperation that was. At thc end of 2002. SANCCOB has asmaller-than-desirable cornplement of dedicated employees.They shoulder a huge burden.

If an oil spill crisis werc to develop at this point in time. theneecl for voluntecr assistance will be as large as in rny pr.eviousspill. This need would bc exhibitcd at e\refy level: in everyaspect ofbird care, fl'om veterinarians to bird feeders, and ever.yaspect of the mantgcment of the logistics, flom or:ganising vol-unteers to purchasing lish and medicines. In spite of this, thenew SANCCOB structulc" with an appropriately qualifled chiefexecutive of'ficer'. has placed tl.re organisation in a better position than ever bctbre to play the kcy overall management rolein a future clisis.

The present location ol'SANCCOB on the edge of Rietvleiin Tableview is not icleal. Probletns with avian malaria recur_

especially during summer, and this is associated with the super-abundance of mosquitoes close to a body of fresh water. Inaddition, SANCCOB has the site on a fixed-term lease. Variousoptions for new locations are being considered continuously bythe board. One vision is to make the new SANCCOB centre atourist destination in its own right - a place where visitors cancome and see penguins and other seabirds, and learn about theirlifestyles and the factors which threaten them.

The contribution that SANCCOB has made to penguin con-servation is significant and measurable. Peter Ryan, in his paperin this booklet, has estimated that the African Penguin popula-tion is l97o larger in 2002 as a result of SANCCOB ' s existencethan it would have been otherwise.

If Peter's mathematical models don't convince you ofSANCCOB's impact, take a stroll through the penguin colonyon Robben Island. Peer at the groups of birds huddling underthe alien rooikrans trees on the island. You cannot but fail to beimpressed by the proportion of these birds bearing the distinc-tive"Treasure-model" flipper bands that were produced for usby Schuurman Engineering during the spill. In many of theselittle huddles, 60-80Vo of the penguins have Treasure bands.You have to pinch yourself to remember that these birds wouldall have been dead had it not been for the existence of SANCCOBat their time of need.

This is the appropriate point to highlight the contributionwhich the flipper-banding of African Penguins has made to ourunderstanding of the life history of this species in general andespecially to measuring the effectiveness of SANCCOB. Flip-per bands make penguins unique and recognisable to research-ers, and thus the lives of individual birds can be followed. Thedatabase generated by the bands is huge and consists of theoriginal banding data, the dates and places of resightings ofthose penguins alive and details of birds found dead. Thisdatabase is curated by the South African Bird Ringing Unit(SAFRING), one of the core projects of the Avian DemographyUnit at the University of Cape Town. The information in thisdatabase has been used for many purposes: for example, todetermine the age at first breeding, to estimate survival fromfledging to that first breeding attempt, to estimate adult survival,and to unravel movement patterns. In the context of this book-let, flipper-banding results have enabled us to estimate and com-pare the survival rates and breeding success of SANCCOBgraduates in relation to penguins that have never been oiled. Infact, many of the papers in this booklet could not have beenwritten without the insights delivered by the bands.

When the next oil disaster strikes the African Penguins, thereis not a week of time to get an organisation up and running. Itsimply has to be in place. It has to be operating, year in and yearout, waiting and in readiness. It has to be training a core groupof loyal "peace time" volunteers who wilt rapidly be able tomultiply their skills on the "war time" volunteers who are ab-solutely critical to SANCCOB's success in emergencies.

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" Contr osting fortu nes "

lsBN 0-620-30012-4

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