Winter home range sizes of female woodland caribou in the boreal forest of Northwestern Ontario
Abstract
Woodland caribou (Rangifer tarandus caribou Gmelin) are listed as “threatened” under
the Canadian Species at Risk Act. Fourteen ranges occur within the continuous
distribution of caribou in Ontario and have been studied using Global Positioning
System (GPS) tracking technology. The Ontario Ministry of Natural Resource and
Forestry (OMNRF) employs the use of Argos GPS collars to track caribou movements
throughout the province. The purpose of this study was to examine the winter home
range sizes of caribou in both a managed and unmanaged forest in northwestern Ontario
and to relate winter home range sizes the level of disturbance in the area. Home range
sizes were estimated from GPS collaring data using a 95% minimum convex polygon
computed using the adehabitatHR package in R statistical programming. Home range
sizes were evaluated using simple linear regressions with disturbance as the dependant
variable. Home range sizes were most strongly negatively correlated with natural and
anthropogenic disturbance in the entire study area (R2 = 0.239). In the unmanaged forest,
the level of disturbance was low (20%) home range sizes were large (1580 km2 ± 1374
km2). Conversely, where disturbance was high (42%), especially at the species’ southern
range limit, home ranges were low (408 km2 ± 311 km2). In the boreal forest, female
caribou may restrict their ranges amid anthropogenic disturbances. Forest harvesting
creates small habitat patches that may serve as ecological traps for caribou and increase
the risk of predator detection. Therefore, smaller home ranges may serve as an indicator
of habitat loss for caribou.
Collections
- Undergraduate theses [325]