Cougar (<i>Puma concolor</i>) predation on Northern Mountain Caribou (<i>Rangifer tarandus caribou</i>) in central British Columbia

Abstract

Caribou (Rangifer tarandus) populations are sympatric with Cougars (Puma concolor) in only a few areas, primarily in western Canada. Records of Cougar–Caribou interactions are limited and no published accounts describe Cougar predation on the shallow-snow, terrestrial-lichen-eating Northern Mountain Caribou (Rangifer tarandus caribou), referred to as Designatable Unit (DU) 7 by the Committee on the Status of Endangered Wildlife in Canada. In 2018 and 2019, two incidents of confirmed Cougar predation on radio-collared Caribou were documented in the declining Itcha-Ilgachuz subpopulation in west-central British Columbia. To the best of our knowledge, this is the first published record of Cougar predation on DU7 Northern Mountain Caribou. Increased landscape disturbance and climate change may be increasing apparent competition between deer (Odocoileus spp.), feral Horses (Equus ferus caballus), and Caribou, leading to Cougar predation in areas of Caribou range where it previously has not been documented. Cougar predation may become a conservation concern, as declining Caribou herds are susceptible to any increased predation pressure.

Ecological Interactions Involving Feral Horses and Predators: Review with Implications for Biodiversity Conservation

“…America, what role will the increase in biomass of feral horses play in the conservation and management of atrisk species? For species like woodland caribou, we especially require additional quantitative data and analysis on this topic further to the conjecture or anecdote presented herein or in recent papers (e.g., White et al 2020). Conservation biologists should approach the subject not only in terms of understanding the potential magnitude of negative influences on alternate prey through apparent competition, but also positive influences for at-risk predators including wolves in the lower 48 states of the United States, and grizzly bears in the Rocky Mountains of the United States and Canada.…”

“…Although predator subsidization by horses to the detriment of native elk, moose, and deer populations may increasingly become important in places like Alberta, habitat loss and apparent competition with native prey is already affecting threatened woodland caribou populations in closely adjacent ecosystems (Wittmer et al 2007, Hervieux et al 2013). Apparent competition with feral horses has already been suggested as a contributor to population declines for caribou in central British Columbia (White et al 2020), and there is little to suggest that feral horses will not also eventually colonize other woodland caribou ranges in western Alberta and eastern British Columbia, imparting further stresses on the at‐risk species.…”

Incorporating mechanism into conservation actions in an age of multiple and emerging threats: The case of boreal caribou

“…In eastern Canada, coyote predation has had a large negative effect on calf survival of caribou (e.g., ~64% of known mortalities) and is thought to be additive to bear predation (Frenette et al, 2020). Cougars are also expanding northward (Knopff et al, 2014) and cougar predation of mountain caribou is now occurring in areas where it has not been previously reported (White et al, 2020). PDs are likely facilitating cougar expansion by increasing the extent of edge habitats, which cougars select (Knopff et al, 2014), and by increasing deer abundance (Pierce et al, 2012).…”