Caribou, Whales, and Environmental Variability
Craig NicolsonUMass Amherst, Natural Res.Conservation
IPY Polar Connections Institute
Photo: Craig George
Caribou migration…
How do we know where they go?
Caribou migration…
How do we know where they go?
Animations at:www.carmanetwork.com for 2 dozen herds
Photo: Gary Kofinas
Population dynamics…
How many caribou are there?Increasing or decreasing?Carrying capacity?
Population dynamics
Porcupine Caribou Herd Size
140000
178000
160000
110000102000 105000
129000
165000
152000
135000137000
123000
60000
110000
55000
0
20,000
40,000
60,000
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1953 1958 1963 1968 1973 1978 1983 1988 1993 1998 2003
# of
car
ibou
Porcupine Caribou calf ratios
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1982 1984 1986 1988 1990 1992 1994 1996 1998 2000
calv
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ows
Birth rateJuly calf:cowMarch calf:cow
• Birth rates aren’t declining in an obvious way• Calf survival rates don’t account for the decline• Computer models show high sensitivity to adult survival rates
Compare PCH with other Alaskan herds
• Much slower growth rate (lambda) over same time period
Habitat Condition and Caribou Forage
How do we measure habitat quality??
Large areas Difficult to estimate forage abundance
only with traditional fieldwork Satellite imagery…
Beaufort Sea
Extent of Calving 1983-2000
Annual Calving Ground
Concentrated Calving
r2 = 0.85
Griffith et al 2003.
4. Caribou and oil-fieldsCentral Arctic Herd analogy
Two effects: behavior & displacement
1. altered activity and behavior higher energy expenditure
2. displacement to poorer foragereduced food intake less energygreater exposure to predators
Impacts of negative energy budget lower probability of calf survival lower probability of conceptionlower probability of survival of the individual
Effects of Development on Activity(Field study)
Effects of Development on Activity(Field study)
0%0%0%0%
10%10%10%10%
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30%30%30%30%
40%40%40%40%
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%Feed%Feed%Feed%Feed %Lie%Lie%Lie%Lie %Stand%Stand%Stand%Stand %Walk%Walk%Walk%Walk %Run%Run%Run%Run
Pe
rce
nt
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eP
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en
t T
ime
Pe
rce
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Tim
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t T
ime
NoNo DevelopmentDevelopment
High DevelopmentHigh Development
Murphy 1998
And now for something…
… completely different
40 ft
Icebreaking Skull (bow…)
Blubber layer 2 ft thick
(floating thermos flask)
Eat around 1,800 kg of plankton / day
Weigh up to 60 tons
(tongue alone weighs 900 kg)
Enurmino
InchounUelen
Lavrentia
Yanrakinnot
SirenikiEnmelenNuneigran
Nutepelmen
Lorino
Annual Bowhead Whale migration cycle…
Sea ice animations:
http://nsidc.org/data/seaice_index/archives/image_select.html
http://alaska.usgs.gov/science/biology/wandering_wildlife/
J
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Spring whaling (ice leads)
Fall whaling (open water)
winter• repair boat frame• clothing (parkas)• hunt caribou
spring• ugruk skin (umiaq)• cover boat• clean ice cellar• cut ice road to campsummer
• ugruk hunting• meat, skin, oil• motorboat mainten.
Whaling is a year-round activity…
Spring hunting April 20 – May 31
– set up camps on shorefast ice – umiaqs perched on edge– whales swim in ice leads
Fall hunting Sep 1 – Oct 15
– early at Kaktovik (Sep 1 – 15)– later at Barrow (Sep 10 – Oct 20)– whales migrating west and feeding at plankton ‘hotspots’– hunting done in open water before sea freezes over– motorized boats, hunt collectively and tow back to shore– BIG job!
The Institutional Context Whaling crews: husband/wife, co-captain, 10-15
Barrow Whaling Captains’ Association (BWCA)– Community leaders: Elders– Decide collectively on local best practice for whaling
International Whaling Commission– 1946: Intl’ Convention for the Regulation of Whaling– Purpose: conservation of whale stocks whaling industry– 60 member nations
Alaska Eskimo Whaling Commission– Created in 1978; 10 commissioners (locally elected)– Divide the IWC quota between villages– Keep track of inter-village quota transfers
Policy Context/History (IWC) Aboriginal subsistence whaling is seen as being
different to commercial whaling
Three goals:– Ensure risks of extinction not seriously increased – Enable harvests for cultural and nutritional requirements;– Maintain stocks at highest net recruitment level and if below
that ensure they move towards it.
1977: scientific stock assessment 1,300 whales– IWC banned all harvest until NOAA had better numbers– AEWC formed, argued successfully for a small quota (1978)– North Slope Borough Wildlife Management Dept– Gradually increased quota from 18 (1978) to 70 (today)
The Cultural Context “We have developed a kindred relationship with this
great animal. We have a familiarity with the whale that no other people has…” – George Ahmaogak
“Iñupiaq food is social food” - Fanny Akpik
The whale’s gift…– “the bowhead is a very distinguished animal. It can give
itself up, which can make it very easy for the captain and crew, or it can withhold itself from another captain and crew and be struck and lost” - Ida Koonik
– Ice cellars: must be cleaned, prepared, meat shared– Words are important– “When you hunt in harmony, you don’t have trouble
catching the animals”
…how this research began
Whales are essential to culture & subsistence The demand for meat is constant year to year. Effort put into hunting is roughly the same year to year So then…
…why does whale harvest vary so much??
A puzzling question
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Whales Landed at Barrow in Spring
Spring hunt Bowhead harvest
(Barrow )
Environmental conditions
Whale availability
Good quality meat and maktak
Quota
What factors affect hunting success?
– Craig George & Harry Brower Jr spoke to captains
– Four main themes emerged
Lead condition
Ice condition (camp, transport)Environmental
conditions
Ice conc. in lead
Rough water
Lead widthFog
Fall freeze-up
TemperatureBlowing
snowSea smoke
Wind (speed, dir)
Multi-year ice
Ocean currents (speed, dir)
Abrupt sea level change
Spring hunt Bowhead harvest
(Barrow )
Quota
Lead condition
Ice condition (camp, transport)Environmental
conditions
Ice conc. in lead
Rough water
Lead widthFog
Fall freeze-up
TemperatureBlowing
snowSea smoke
Wind (speed, dir)
Multi-year ice
Ocean currents (speed, dir)
Abrupt sea level change
Spring hunt Bowhead harvest
(Barrow )
Quota
What factors affect harvest success?
Wind speed
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Daily average wind speed (km/h)
Fre
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All days
Harvest days
Spring daily wind speed in Barrow
Wind direction
Daily wind speed and direction(Vector plot)
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Wind speed from east (km/hr)
Win
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eed
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r)
We have daily wind data for Barrow airport…
Plot each day’s average wind conditions on a vector plot to show both speed and direction…
N
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Apr 20
Apr 23, 1997ESE, 23km/h
Apr 22
Apr 21
Spring hunting season in Barrow April 20 – May 31 From 1990 to 1997
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Look at the wind direction on successful harvest days
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All days
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Red dots: days with whale harvest
Note how winds are almost always from the east when whales are taken in spring (east winds open the ice lead).
Scientific and quantified representation of the captains’ understanding of effect of wind.
Climate strongly impacts spring hunting…
Policy Implications – International Whaling Commission– Subsistence quota may be reduced if it is not used– This shows that there may be good reasons why whale
harvest is low in some years: not a function of need
y = 0.0794e0.049x
R2 = 0.9602
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'Good wind' day weighted index (Apr-20 to May31)
% o
f quo
ta fi
lled
Fall whaling hypotheses… Driven by quota: they get ‘x’ in spring, and
then in the fall they make up the balance of the annual quota (Q-x)
Wind, ocean, ice conditions
Whale migration patterns– Distance offshore (ice, oil activity)– Timing (stop to feed, ice could come in)
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Wind speed (km/h)
Harvest days
All days
Fall wind speed frequency distribution
Spring wind vector plot 1990-1997
Fall wind vector plot 1990-1997
Wind conditions in fall
Bowhead Migration Fall hunt
– Minerals Management Service: BWASP– Fall aerial surveys, 1987-2005– Sighting locations by date and # seen– Need to correct for flight transect effort
Migration is affected by sea ice…
Mapping activity…
Groups of 2 Before lunch:
– Plot up transect lines– … and sightings on that flight
After lunch– Add in other observations– Compare