Monitoring - Wildlife

Porcupine Caribou Herd Monitoring

Government of Yukon, Canadian Wildlife Service, Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service

Rationale

Martin Kienzler and Loralee Laberge with Catherine, he newest caribou of the satellite monitoring program, March 2002.

The Porcupine caribou herd is a large population of barren-ground caribou which migrate throughout the northern Yukon, Alaska and Northwest Territories. In 2001 the size of the herd was estimated at 123,000 caribou. 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 Government of Yukon, the Canadian Wildlife Service, the Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service. Parts of this work are conducted under the direction of the Porcupine Caribou Herd Management Plan. Parks Canada 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, adult female mortality and 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 post-calving grounds. The photocensus is usually conducted in the Arctic National Wildlife Refuge in Alaska.
• Classification surveys are conducted entirely by helicopter or 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 starting in late May. Cows are located daily until they give birth and then located again in approximately 1 week to document perinatal calf mortality. Another survey is done in late June or early July to calculate calf survival rates to 1 month of age. Calf survival to 9 months of age is documented during the March composition count, .
• Adult female mortality rates are estimated from death rates of satellite and radio collared female caribou.
• Satellite collars are used to determine the seasonal distribution and movements of the herd, and form the basis for involving schools in several environmental educational programs.

Years of Data

• Population estimates have been conducted since 1972.
• Calf mortality data, cow calf ratios and birth rates have been collected since 1983.
• Seasonal range use has been documented since 1970.

Partners

• Alaska Department of Fish and Game (project lead)
• U.S. Fish and Wildlife Service (project lead)
• Governement of Yukon (project lead)
• Canadian Wildlife Service (project lead)
• Government of the Northwest Territories

Results

• The last photocensus was conducted in 2001. This photocensus estimated 123,000 caribou in the herd. The next photocensus is scheduled for 2003.
• A composition count telemetry flight and capture session was completed in March of 2002. 23 new cows were equipped with conventional telemetry collars.
• One cow was equipped with a satellite collar and one collar was replaced in 2002.
• Telemetry flights were conducted from May 30 to June 7, 2002, to locate cows and observe if they had produced calves. Follow-up flights on June 25 and 26, 2002 were undertaken to determine calf survival and locate bulls and nonpregnant cows that had not been located previously.
• Calf production in 2002 was up from 2000 and 2001. However, because the calf:cow ratio was lower from 1994 to 1999, it is feared that current levels of reproduction are not enough to stop the decline in herd size that has occurred since 1989.

Population estimates for the Porcupine Caribou Herd

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

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