uoo tuatara research at oe
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Tuatara Research at Orokonui Ecosanctuary – to 1 September 2014 Tuatara Research Team, Department of Zoology, University of Otago Leader: Associate Professor Alison Cree [email protected] Tuatara (Sphenodon punctatus), an iconic rhynchocephalian reptile found only in New Zealand, were translocated to Orokonui Ecosanctuary in late 2012. The translocation occurred following prior research over several years to establish the thermal suitability of Orokonui for tuatara. The translocation involved juveniles and adults from the genetic stock of Stephens Island (Takapourewa), and proceeded with the support of Ngāti Koata (kaitiaki of tuatara on Takapourewa) and Kāti Huirapa Rūnaka ki Puketeraki (mana whenua for Orokonui). Ongoing monitoring of the translocated animals, including comparisons between captive-‐reared and wild juveniles, involves the assistance of Orokonui staff and volunteers. Publications to date are described below, in order of appearance.
Some of the Cree lab group photographed with ‘practice’ tuatara for radio-‐telemetry at Orokonui Ecosanctuary, November 2012.
Rear, L to R: Merenia Wright, Sophie Penniket, Alison Cree, Sam Botting, Stephen Adolph (visiting researcher). Front, L to R: Sophie Gibson, Scott Jarvie. Absent: Anne Besson. Photo: collection of Alison Cree
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A cold-‐adapted reptile becomes a more effective thermoregulator in a thermally challenging environment
Anne A Besson and Alison Cree Department of Zoology, University of Otago, P.O. Box 56 Dunedin, New Zealand
Oecologia (2010) 163: 571–581 DOI: 10.1007/s00442-‐010-‐1571-‐y We conducted a laboratory experiment to test whether tuatara (Sphenodon punctatus) modify their thermoregulatory behaviour in response to different thermal environments. We provided tuatara with three thermal treatments: high-‐quality habitat (their preferred temperature (Tsel) could be reached for 8 h/day), medium-‐quality habitat (Tsel available for 5 h/day) and low-‐quality habitat (Tsel available for 3 h/day). The medium-‐quality habitat mimicked the availability of Tsel for copper models of juvenile tuatara at Orokonui Ecosanctuary in autumn. We found that tuatara were capable of adjusting their thermoregulatory behaviour in response to different thermal constraints, by basking more actively when their environment becomes more challenging. This result has implications for the conservation of the species. If tuatara are translocated to cooler regions (e.g.: Orokonui Ecosanctuary), they should adapt to their new thermal environment by engaging in more effective thermoregulatory behaviour.
A juvenile tuatara seen basking several months after release at Orokonui Ecosanctuary. Photo: Alison Cree.
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Is cool egg incubation temperature a limiting factor for the translocation of tuatara to southern New Zealand?
Anne A. Besson1, Nicola J. Nelson2, Cathy M. Nottingham1 and Alison Cree1
1Department of Zoology, University of Otago, PO Box 56, Dunedin 9054, New Zealand 2Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Victoria University of Wellington, New Zealand
New Zealand Journal of Ecology (2012) 36(1): 90-‐99 http://www.nzes.org.nz/nzje/3012 In this study, we examined whether cool incubation temperature is a limiting factor for the reintroduction of tuatara to Orokonui. Cool southern temperatures may produce only females as tuatara is a species with temperature-‐dependent sex determination, with females being produced at low incubation temperatures, and males at high incubation temperatures. In 2007, we experimentally translocated tuatara eggs to the Ecosanctuary and found that temperatures at those sites would produce only female hatchlings. However, additional assessments of soil temperatures at other sites in 2008 indicated that some sites were warm enough for males to be produced. In 2012, tuatara were translocated to the sanctuary, and monitoring of female nesting behaviour, including nest locations and resulting temperatures, is currently underway.
Anne Besson checks on a temperature data logger alongside a tuatara egg in a nest at
Orokonui Ecosanctuary, March 2014. Photo: Alison Cree
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Adjustment of juvenile tuatara to a cooler, southern climate: operative temperatures, emergence behaviour and growth rate RSR Mellob, AA Bessona, KM Harec, V Fayd, E Smithd & A Creea a Department of Zoology, University of Otago, Dunedin, New Zealand b HRT Oil & Gas, Manaus, Brazil c Research Office, Victoria University of Wellington, Wellington, New Zealand d Orokonui Ecosanctuary, Dunedin, New Zealand New Zealand Journal of Zoology (2013) 40(4): 290-‐303 DOI: 10.1080/03014223.2013.775167 http://dx.doi.org/10.1080/03014223.2013.775167 In this paper we investigated how captive-‐reared juvenile tuatara adjusted to outdoor, predator-‐protected pens at Orokonui Ecosanctuary. We found that the tuatara were able to reach their preferred body temperature in summer by basking, and that burrows offered protection in winter from freezing temperatures. We compared the growth rates of these Orokonui-‐reared juveniles to those of juveniles at four other captive-‐rearing facilities in New Zealand and found that they were within a similar range. The captive Orokonui juveniles grew at a faster rate than wild juveniles on Stephens Island (Takapourewa) in Cook Strait. We concluded that the climate at Orokonui was suitable for growth of juvenile tuatara, providing encouragement for a free release.
Left: Captive-‐reared juvenile tuatara being checked by Valerie Fay (volunteer) and Tahu Mackenzie
(Educator). Right: Juvenile tuatara being measured for snout-‐vent length (SVL). Photos: collection of Alison Cree
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Attaching radio transmitters does not affect mass, growth or dispersal of translocated juvenile tuatara (Sphenodon punctatus) Scott Jarvie1, Edward A Ramirez1, Jignasu Dolia1, Stephen C Adolph1,2, Philip J Seddon1 and Alison Cree1 1Department of Zoology, University of Otago, P.O. Box 56 Dunedin, New Zealand 2Department of Biology, Harvey Mudd College, 301 Platt Boulevard, Claremont, California 91711 USA Herpetological Review: in press This paper addresses a key gap in knowledge regarding the use of radio telemetry to monitor juvenile tuatara (Sphenodon punctatus). We compared the performance of tagged versus untagged juveniles reintroduced to Orokonui Ecosanctuary. Our results showed that over the five months following release, tagged and untagged juveniles had similar growth rates, body mass and dispersal distance. We found that our modified backpack harness had no apparent effects on the behaviour of juveniles, although occasional abrasion and/or swelling were noted. In summary, we encourage more telemetry studies of reptiles to use comparative data from tagged and untagged animals to evaluate the effects of monitoring, an admittedly difficult task, especially for juveniles due to their cryptic nature and secretive behaviours.
Scott Jarvie assesses a juvenile tuatara prior to its release at Orokonui Ecosanctuary. Photo: Alison Cree
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Assessing the thermal suitability of translocation release sites for egg-‐laying reptiles with temperature-‐dependent sex determination: a case study with tuatara (Sphenodon punctatus) Scott Jarvie, Anne A Besson, Philip J Seddon and Alison Cree Department of Zoology, University of Otago, P.O. Box 56 Dunedin, New Zealand Animal Conservation: in press In this paper we provide a strategic framework for evaluating the thermal suitability of a release site for egg-‐laying reptiles with temperature-‐dependent sex determination. This is an important aspect of habitat assessment for reptile reintroductions. We apply the framework to a case study of tuatara (Sphenodon punctatus) reintroduced to Orokonui Ecosanctuary, south-‐eastern South Island, New Zealand. Our approach allows the assessment of the thermal suitability of future translocation sites for tuatara, and can be readily modified for any translocation of a reptile species with temperature-‐dependent sex determination.
Head of a juvenile tuatara with distinctive red colouration, photographed prior to release at Orokonui Ecosanctuary. Photo: Scott Jarvie.
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Tuatara: biology and conservation of a venerable survivor Alison Cree Canterbury University Press (2014) For ordering see http://www.cup.canterbury.ac.nz/new/ or www.nationwidebooks.co.nz This book provides a comprehensive summary of the evolution, biology and conservation of tuatara and is illustrated in colour throughout. Topics include the history of human interactions with tuatara, including those relating to Māori culture and to scientific study. Biological topics include ecology, feeding and behaviour; reproduction and life history; and environmental relations. The history and current status of the 32 natural populations on islands, as well as populations recently translocated to islands or to mainland fenced ecosanctuaries, are also discussed. Included among these is Orokonui Ecosanctuary, home to 87 tuatara translocated in late 2012.