Denby S. Lloyd, Commissioner
Jennifer Yuhas, Communications Director
P.O. Box115526
Juneau, Alaska 99811
Phone: (907) 465-6137 • Fax: (907) 465-2332
Press Release: No. 09-19, July 2, 2009
Contacts: Pat Valkenburg (907) 459-7263
Southern Alaska Peninsula Caribou Herd Calf Survival Increases
Work at restoring the Southern Alaska Peninsula (SAP) caribou herd has resulted in another bumper crop of calves and the removal of at least eight wolves. For the second year in a row, Alaska Department of Fish & Game biologists collared cows and newly born calves to track their survival and investigate any deaths.
The pregnancy rate for radio-collared adult cows in 2008 and 2009 was 90 percent. “This is an excellent rate and indication that the herd is nutritionally strong and in good health.” said Doug Larsen, Director of the Division of Wildlife Conservation.
Calf body weights were similar to those recorded when the SAP herd was previously growing. The weights and early survival support biologists’ conclusion that nutrition is not limiting their growth or survival.
Seventy-eight calves were monitored. As of June 15, 71 percent remained alive. That is a slight increase from last year’s 69 percent and higher than other Alaska caribou herds that are considered stable or increasing.
This year six adult wolves, from at least two different packs, were removed by department staff deployed in helicopters following wolf caused mortality of several caribou calves. Two of the wolves were lactating females. Biologists located one den site and employed the most humane methods available to them, carbon monoxide (CO) to euthanize at least two remaining pups. CO is recommended by the American Veterinary Medical Association as an acceptable method of euthanasia (AVMA Guidelines on Euthanasia, June 2007). An effort, to find and remove wolves from the calving grounds before denning season in April was unsuccessful due to poor weather and snow conditions.
Last year calf survival to October of 2008 was 39%. This is a significant increase in caribou survival. During the two previous years calf survival to fall was 1 percent or less. Similar to last spring, 23 calves were killed in the first two weeks of life. Twelve were killed by wolves and four by bears. Four more were killed by undetermined large predators. One calf died by drowning, one of starvation, and one of undetermined causes. This is again comparable to last year. Most caribou calf mortality occurs during the first few weeks of life. Telemetry flights will be flown periodically throughout the summer to document further mortality. This fall, a sex and age composition count will be conducted to determine the effect of the predation reduction program.
Pat Valkenburg, Deputy Commissioner of Wildlife said “Today’s estimate of 800 caribou indicates the beginning of recovery for this herd. Before intensive management efforts in this unit the herd had dropped from 4,100 to a low of 600 animals.”
###
