Porcupine Caribou Herd Monitoring
Yukon Territorial Government, Canadian Wildlife Service, Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service
Rationale
 |
| Don Russell observing caribou on the Yukon North Slope. |
The Porcupine caribou herd is a large population of barren-ground caribou in the northern Yukon, Alaska and Northwest Territories. In 2001 the size of the herd was estimated at 123,000 caribou. The herd is an important part of the arctic ecosystem and resource for aboriginal people. Information about the Porcupine caribou herd is required for understanding the current status of the herd and how it is changing. Current monitoring is important because of existing and planned developments in the range of the herd, and changes in the arctic environment. Existing and planned developments include roads and oil and gas exploration and development in the calving grounds and in the wintering range of the herd. Changes to the arctic environment include the long range transport of pollutants and climate warming. This project is conducted by the Yukon Territorial Government, the Canadian Wildlife Service, the Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service. Parks Canada Agency is a partner in this project, contributing funds and other resources towards the project.
Objectives
- To estimate the size, age and sex composition, body condition, productivity and over winter survival of caribou calves, female mortality, distribution and movements of the Porcupine caribou herd.
Methods and Information Collected
- Surveys are conducted throughout the range of the herd in northern Alaska, Yukon and the Northwest Territories.
- A photocensus of the Porcupine caribou herd is attempted every three years while the herd is congregating on their calving grounds. The photocensus is usually conducted in the Arctic National Wildlife Refuge in Alaska.
- Classification surveys are conducted by positioning surveyors near groups of caribou with a helicopter. Caribou are observed with spotting scopes or binoculars and classified by age and sex.
- A calving survey is conducted by locating satellite and radio collared caribou in early June. The number of cows with calves and pregnant cows are counted.
- Radio and satellite collared cows are located and observed periodically until the end of June to determine birth rates and survival rates.
- Female mortality rates are estimated from death rates of satellite collared female caribou.
- Satellite collars are used to determine the distribution and movements of the herd.
Years of Data
- Herd size data has been collected since 1972.
- Calf mortality data, cow calf ratios and birth rates have been collected since 1983.
- Winter range data has been collected since 1992.
Partners
- Alaska Department of Fish and Game (project lead)
- U.S. Fish and Wildlife Service (project lead)
- Yukon Territorial Government, Renewable Resources (project lead)
- Canadian Wildlife Service (project lead)
Results
- A photocensus was completed in Alaska on July 3, 2001. This photocensus estimated 123,000 caribou in the herd.
- A composition survey was not completed in 2001 due to poor weather.
- Birth and survival rates for 2001 are based on collared cows.
- In March 2001, 10 bulls and 33 cows were equipped with radio collars.
- Snow depth and density was measured in March 2001 at 8 stations along the Dempster Highway to aid in monitoring winter range conditions.
- A check station was operated on the Dempster Highway during the fall 2001 to monitor harvest levels.
- 360 samples were collected from harvested animals in September 2001 to assess body condition
Birth rates, calf survival, calf to cow ratios and population estimates for the Porcupine Caribou Herd, 1972-2001. Source: Porcupine Caribou Management Board, Alaska Department of Fish and Game.
| Year |
Birth Rate (%) |
June Calf Survival (%) |
July Calf/Cow (per 100) |
March Calf/Cow (per 100) |
Population Estimate |
1972 |
|
|
|
|
100,000 |
1977 |
|
|
|
|
105,000 |
1979 |
|
|
|
|
110,000 |
1983 |
|
|
|
|
135,000 |
1987 |
78 |
|
55 |
|
165,000 |
1988 |
84 |
|
62 |
|
|
1989 |
|
78 |
58 |
43 |
178,000 |
1990 |
82 |
|
74 |
|
|
1991 |
72 |
89 |
58 |
22 |
|
1992 |
86 |
74 |
49 |
33 |
160,000 |
1993 |
68 |
83 |
45 |
32 |
|
1994 |
90 |
93 |
70 |
40 |
152,000 |
1995 |
69 |
92 |
59 |
41 |
|
1996 |
89 |
91 |
72 |
46 |
|
1997 |
75 |
90 |
57 |
38 |
|
1998 |
83 |
94 |
68 |
27 |
129,000 |
1999 |
84 |
86 |
70 |
56 |
|
2000 |
71 |
63 |
44 |
|
|
2001 |
81 |
61 |
|
28 |
123,000 |
Contacts
Dorothy Cooley
Regional Biologist
Department of Environment
P.O. Box 600 (R-5R)
Dawson City, YK Y0B 1G0
Phone: (867) 993-6461
Fax: (867) 993-6548
Dorothy.Cooley@gov.yk.ca
Porcupine Caribou
Management Board
P.O. Box 31723
Whitehorse, YK Y1A 6L3
Phone: (867) 633-4780P
cmb@polarcom.com
Ian McDonald
Conservation Biologist
Parks Canada
P.O. Box 1840
Inuvik, NT X0E 0T0
Phone: (867) 777-8807
Fax: (867) 777-8820
Ian.McDonald@pc.gc.ca