Ecological Archives A021-105-A1

John A. Nagy, Deborah L. Johnson, Nicholas C. Larter, Mitch W. Campbell, Andrew E. Derocher, Allicia Kelly, Mathieu Dumond, Danny Allaire, and Bruno Croft. 2011. Subpopulation structure of caribou (Rangifer tarandus L.) in arctic and sub-Arctic Canada. Ecological Applications 21:2334–2348.

Appendix A. History of satellite tracking studies undertaken in the Northwest Territories and Nunavut, Canada, 1993–2009.

Satellite tracking studies have been ongoing since 1993 to document the movements of female barren-ground caribou in the Northwest Territories (NT) and Nunavut (NU), Canada. In eastern NU, satellite collars were first deployed in 1993 and by 2009 movement data for 155 females had been obtained. Satellite collars were typically deployed along spring migration routes or uniformly across late winter ranges. In the NT and western NU, 94 satellite collars were deployed on females in 1996–2004 to support various habitat use and subpopulation and range delineation studies. The number of active satellite collars varied over time and among females using each calving ground. After 2004, females were collared (N = 156) in preparation for subpopulation surveys. Reconnaissance surveys were flown during late February and early March 2005, 2006, and 2008 to document the distribution of caribou on winter ranges. Satellite collars were then deployed as uniformly as possible, given weather and logistical constraints, throughout these winter ranges. By 2006 satellite tracking studies designed to obtain detailed information on the movements and distribution of 5 of the 6 recognized migratory barren-ground caribou subpopulations were underway and data for a large number of females in the Cape Bathurst (N = 23), Bluenose-West (N = 31), Bluenose-East (N = 34), Bathurst (N = 56), and Qamanirjuaq (N = 41) subpopulations had been obtained. In comparison, based on use of calving grounds it was believed that only 2 females in the Beverly subpopulation had been tracked and that the distribution and movements of this subpopulation was largely unknown. The first study that was specifically designed to document the distribution and movements of the Beverly subpopulation was initiated in 2006 and by 2008, 66 satellite collars had been deployed within their winter and post-calving ranges. A few collars (N = 5) were deployed east of Bathurst Inlet in 1996 to describe the movements of the tundra-wintering Queen Maude Gulf subpopulation (Gunn et al. 2000), however, additional collaring (N = 10) did not begin until 2008. Studies designed to describe the distribution and movements of the tundra-wintering Lorillard and Wager Bay subpopulations began in 1999. These studies gave sufficient data to assess subpopulation structure among females that used most of the calving grounds in the NT and NU in 2006–2009. Although the number of satellite collared females tracked in 1993–2005 varied annually, they provided movement data with which we could assess subpopulation structure among females using each calving ground and their area fidelity. Similarly, satellite tracking data were obtained for 39 female Dolphin and Union island caribou in 1999–2006, allowing us to assess subpopulation structure among island and adjacent barren-ground caribou.

The first satellite tracking studies for boreal caribou began in the NT in 2002 to obtain data required to assess the potential impacts of the proposed Mackenzie Valley Pipeline (Ray Case, pers. comm.). Boreal caribou were also listed as Threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC 2002) that year. By 2004, studies were underway throughout their range in the NT and into northern Alberta (AB) and Yukon Territory (YT) to obtain demographic, habitat, and range use data. Initially, reconnaissance surveys were conducted and satellite collars were deployed uniformly in 5 study areas including the Gwich’in and Sahtu settlement areas, the Dehcho and South Slave regions, and in the Cameron Hills, NT and AB. In subsequent years, movement data were analyzed before capture work and satellite collars were deployed to fill in gaps. The location data obtained for 176 female boreal caribou in 2002–2009 allowed us to assess subpopulation structure among females within and among these study areas.

A mountain woodland caribou satellite tracking study was conducted in the Mackenzie Mountains, NT in 2001–2005, however, the sample size of collared females (N = 11) was too small to assess subpopulation structure. We included data for these caribou when comparing annual home range size and path length among ecotypes.


COSEWIC. 2002. COSEWIC assessment and update status report on the woodland caribou Rangifer tarandus caribou in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa, Canada.

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