Research

Dall's Sheep Winter Range Survey

Rationale

The size of Dall's sheep populations can be limited by the amount of winter range. In the winter, Dalls's sheep require areas near rugged terrain that have a soft, shallow snow cover or are blown free of snow. There is a small population of Dall's sheep that overwinters in Ivvavik National Park (population surveys conducted in the park in 1984, 1986 and 2001 found 84-171 sheep). These sheep are mainly found in the mountainous areas of the park west of the Firth River, and are likely part of the larger Brooks Range population in Alaska. A survey to determine Dall's sheep winter range was conducted in March, 2002 to determine if winter range is limiting the size of the sheep population in Ivvavik National Park.

Objectives

• To determine the extent of Dall's sheep winter range in Ivvavik National Park.

Methods and Information Collected

• A helicopter survey was flown from March 18-20, 2002.
• This survey was conducted in the mountainous area between the Firth and Malcolm rivers. This is the same area that was flown for the Dall's sheep population survey that was conducted in June 2001.
• Total flying time for the survey was 9.7 hours.
• The location of sheep observed during the survey was recorded. Sheep were classified into one of 7 sex and age categories, when possible.
• The location of other wildlife observed during the survey was also recorded.

Partners

• Government of Yukon, Department of Environment

Results

• Much of the study area was free from snow in March 2002

  The location of 71 Dall's sheep was recorded during the survey.
• Dall's sheep were observed throughout the study area during the winter range survey. Sheep were slightly more dispersed in the March survey than during the survey conducted in June 2001.
• Preliminary results indicate that there is not a lack of winter range for Dall's sheep in the study area.
• A data report for June 2001 and March 2002 surveys will be produced.

Contacts

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

Winter (red circles) and summer (green triangles) locations of Dall’s sheep in Ivvavik National Park.