Download ODD MODEL PARAMETERS CARIBOU AND WOLF PREDATOR

ODD MODEL PARAMETERS
CARIBOU AND WOLF PREDATOR PREY MODELING
Craig Kasemodel & Gil Santos Bautista
CS699 Agent Based Modeling and NetLogo
Caribou Density
30K per 10000 sq mi
23K per 10000 sq mi
3000 per 1000 sq miles
other research estimates =
.4 caribou/sq km
.5 caribou / sq km
.1 to 1.5 caribou / sq km
Wolf Density
7 per 1000 sq km
21 per 1000 sq km
2.6 to 10 per 1000 sq km
 approximately 7-10 wolves per pack
Wolf Predation Rates (biomass equivalent to one adult moose)
Summer
Winter
1 kill / 7-16 days / pack
1 kill / 5-11 days / pack
Winter kill rate =
if 4 kills / 8 days / pack
then 1 kill / 2-3 days / pack
Ungulate kills averaged 4.6 caribou / wolf / 100 days
5.3 kg of available food/wolf/day
In areas where moose are present; when caribou densities were <200/1,000 sq km;
wolves switched to preying on resident moose
Caribou Weights
350-500 pounds / bull
175-250 pounds / cow
Calories per Caribou
130 kcal per 100 grams of caribou
(compared to a moose at 100 kcal per 100 grams of moose)
other estimates of the biomass energy of a caribou
5.5 million Kcal per caribou
Wolves within the range of the Western Arctic Caribou Herd killed 6-7% of this caribou
population annually.
WAC Population ~ 450,000 caribou over 350,000 sq km for density of 1.5 caribou/sq km
Valkenburg et. al. (1996) found no clear relationship between caribou : wolf ratios or
caribou equivalents : wolf ratio and caribou growth rate. There is appears to be a slight
density-dependent predation in small caribou herds but the growth rate of caribou herds
is more dependent upon stochastic environmental factors (long severe winters) rather
than on caribou density.
Changed weather patterns increase the vulnerability of caribou to predation
Stochastic weather events interact with predation and nutrition to limit herd size within a
range of densities
Nu = Upper bounds of caribou population
Nl = Lower bounds of caribou population
N = number of caribou
Nu  Nl N = f (Amount of suitable habitat, Length of good weather, Length of bad
weather, Interactions of predators, and availability of alternate prey)
“At the upper and lower bounds of the caribou populations, the number of caribou in any
given Alaskan caribou herd is a function of amount of suitable habitat, Length of good
weather, Length of bad weather, Interactions of predators, and availability of alternate
prey.
Factors in Caribou Population: general density dependence, nutrition, predation,
weather, harvest, immigration, habitat loss/quality
Model is missing: stochastic weather effects, black bears, brown bears, low density
dependence equilibrium, caribou calf mortality & survival, wolf mortality & survival,
lichen availability & quality, human harvest & disturbance, &
REFERENCES:
Alaska Wildlife Notebook Series, Alaska Department of Fish and Game. (n.d.).
Retrieved October 12, 2012, from
http://www.adfg.alaska.gov/index.cfm?adfg=educators.notebookseries
Ballard, W. B., Ayres, L. A., Krausman, P. R., Reed, D. J., & Fancy, S. G. (1997).
Ecology of Wolves in Relation to a Migratory Caribou Herd in Northwest Alaska.
Wildlife Monographs, (135), 3–47. Retrieved from
http://www.jstor.org/stable/3830776
Ballard, W. B., Jackson S. Whitman, & Gardner, C. L. (1987). Ecology of an Exploited
Wolf Population in South-Central Alaska. Wildlife Monographs, (98), 3–54.
Retrieved from http://www.jstor.org/stable/3830566
Carlos, A., & Lewis, F. (2010). Commerce by a Frozen Sea: Native Americans and the
European Fur Trade. University of Pennsylvania Press.
Committee on Management of Wolf and Bear Populations in Alaska, & National
Research Council. (1997). Wolves, Bears, and Their Prey in Alaska:Biological and
Social Challenges in Wildlife Management. The National Academies Press.
Retrieved from http://www.nap.edu/openbook.php?record_id=5791
Gasaway, W. C., Stephenson, R. O., Davis, J. L., Shepherd, P. E. K., & Burris, O. E.
(1983). Interrelationships of Wolves, Prey, and Man in Interior Alaska. Wildlife
Monographs, (84), 1–50. Retrieved from http://www.jstor.org/stable/3830554
Haskell, S. P., & Ballard, W. B. (2007). Modeling the Western Arctic Caribou Herd
During a Positive Growth Phase: Potential Effects of Wolves and Radiocollars. The
Journal of Wildlife Management, 71(2), 619–627. Retrieved from
http://www.jstor.org/stable/4495224
Holleman, D. F., & Stephenson, R. O. (1981). Prey Selection and Consumption by
Alaskan Wolves in Winter. The Journal of Wildlife Management, 45(3), 620–628.
Retrieved from http://www.jstor.org/stable/3808695
Smith, E. A. (1991). Inujjuamiut Foraging Strategies: Evolutionary Ecology of an Arctic
Hunting Economy. Transaction Publishers.
Valkenburg, P, R A Sellers, RC Squibb, JD Woolington, AR Aderman, and BD Dale.
2003. (PDF 331 kB) Population dynamics of caribou herds in southwestern Alaska.
Rangifer. 1996. Special Issue 14:131-142.
Wildlife Management and Harvest Reports and Publications, Alaska Department of Fish
and Game. (n.d.). Retrieved October 12, 2012, from
http://www.adfg.alaska.gov/index.cfm?adfg=librarypublications.professionalwildlifep
ubs