ENVIRONMENT YUKON






 

Mammals

Caribou population and distribution

 

Significance

 

Caribou are important ecologically and culturally. Many people in Yukon rely on caribou for subsistence and spiritual well-being. Conserving and protecting key caribou habitat – rutting areas, migration corridors and winter range – is important for herd health and abundance.

Caribou herds that cross jurisdictional boundaries require a coordinated approach to their management. For example, the Porcupine caribou herd has a range which covers Yukon, Alaska, and the Northwest Territories.

 

Woodland caribou. Cameron Eckert.

 

 

What is happening?

 

There are two subspecies of caribou in Yukon, Rangifer tarandus granti and Rangifer tarandus caribou, which represent large migratory (Porcupine, Fortymile and Nelchina) and more sedentary woodland (Northern Mountain and boreal) herds, respectively.

Woodland caribou herds
  • In 2014, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) re-assessed all Northern Mountain woodland caribou in Canada as a Species of Special Concern. These caribou are designated as such under Canada’s Species at Risk Act.
  • Across Canada, boreal woodland caribou are designated as a Threatened Species under Canada’s Species at Risk Act.
  • Of the 26 Northern Mountain woodland caribou herds present in Yukon, four are increasing in size, seven are considered relatively stable and three are declining.
  • The declines in Yukon herds and across the circumpolar north may be due to environmental changes, natural population cycles, or human influences such as harvest and development.
  • Population trends are unknown for 12 of the woodland caribou herds.
  • The Ibex caribou herd is expanding its range to the north, south and west. Information collected by the Department of Environment and by members of the public indicates that this herd is now being seen in areas where it has not been observed for many decades, particularly west of Kusawa Lake.
  • Based on the area of mapped disturbances (human-caused and fire-related), Yukon’s boreal caribou are considered “self-sustaining” (i.e., at least stable), under Environment and Climate Change Canada’s boreal caribou recovery guidelines. Yukon’s boreal caribou are small in number and represent a small fraction of the overall boreal caribou population in Canada and are contiguous with boreal caribou in the Northwest Territories.
Large migratory caribou herds
  • In 2016, COSEWIC assessed all “barren-ground” caribou in Canada as a Threatened Species. Yukon’s Porcupine caribou herd is included in this assessment.
  • The Fortymile and Nelchina herds are not considered “barren-ground” caribou under COSEWIC’s barren-ground caribou assessment and their status has not been assessed.
  • In Yukon, all of the large migratory caribou herds, Fortymile, Nelchina, and Porcupine, are increasing in size.
  • Starting in the winter of 2013-14, the Fortymile caribou herd dramatically increased its presence in Yukon, expanding its recent range to the east and southeast, back to historic ranges last used in the 1960s. This movement of Fortymile caribou into Yukon was aided by conservation actions in Yukon and Alaska initiated in 1995. At roughly the same time, the Nelchina herd also began moving into Yukon during the winter months. Its range in Yukon overlaps substantively with the Fortymile herd.

 

Figure 1: Distribution of caribou herds in Yukon, 2017

 

 

Taking action

 

  • The Department of Environment monitors several caribou herds each year to assess overall status and trends.
  • Recovery plans for woodland caribou populations have been developed under the federal Species at Risk Act.
  • Harvest management plans have been developed for the Fortymile and Porcupine caribou herds in collaboration with co-management partners.
  • An international, multi-jurisdictional management plan for the Chisana herd has been developed

Data quality

  • Caribou herd population status (size and trend) is typically determined through aerial surveys which estimate both herd size and the number of calves produced each year.
  • The Government of Yukon has modified its approach over the past few years to use aerial surveys in combination with radio-collared animals to monitor Northern Mountain woodland caribou herds.
  • This approach has increased the precision of population estimates as well as provided additional information on seasonal ranges and habitat use.
  • The sizes of large migratory herds are estimated using aerial photocensus techniques. The Government of Yukon partners with the Government of Alaska, which leads these surveys.

 

Collared caribou are key for monitoring the Fortymile caribou herd. Scott Cameron.