1999 Chisana Caribou Survey Report
Gardner C. 1999. To: James D. Re: 1999 Chisana Caribou Survey Report
On 1 October 1999 Rod Boertje, Bob Hayes (Yukon Department of Renewable Resources) and I completed the Chisana caribou herd composition and radiocollared 8 5-month female calves. Rod and Bob located 15/16 active collars. Collar distribution was entirely in Alaska. Rod and Bob high graded the Yukon portion of the herd’s range and found tracks of 5-6 caribou but observed none. We located 14 groups and compositioned 318 caribou. Group size ranged from 8-54 caribou (x=22.7, s.d.=15.67). The calf:cow ratio 7.0:100 cows. The Chisana herd has suffered from poor calf recruitment since 1989. The bull:cow ratio was 17.2:100. The bull:cow ratio has declined from 41:100 in 1991. Between 28 September 1998 and 1 October 1999, 3 of 19 radiocollared cows (2 adults and 1 yearling) died (15.8%). Using composition and modeling data, the bull mortality rate was estimated to be 27%. Using Patrick’s model, the fall 1999 estimated herd size was 365 caribou down from about 1,900 in fall 1989 (81% decline). Similar to last year, the few remaining calves in late September-early October are very healthy. We compositioned 18 calves of which 10 were females. We captured 8 of these to radiocollar and to weigh. The average condition index was 4.3 on a scale of 1 to 5 (5 being the highest rank) and the average weight was 139.9 pounds (s.e.=3.38). Between the Yukon Dept. of Renewable Resources and the National Park Service, the herd will be monitored 4-5 times over the winter. I will again conduct surveys during calving and postcalving to document pregnancy and birth rates and early calf mortality.
- Type
- Administrative
- Authors
- Gardner, Craig
- Date of Issue
- 1999
- Publisher
- Alaska Department of Fish and Game
- Units
- WRST
- Keywords
- abundance, alaska, caribou, chisana, Memorandum, population, st. elias, survey, wrangell