Caribou populations in Alberta appear to be declining in most regions. Predation is the proximate cause of most caribou deaths, but a variety of factors can influence the rate of predation on caribou, or combine to limit the growth of caribou populations. For example, resource development can increase access for human hunters, or increase the hunting efficiency of wolves and other natural predators. Greater road density in caribou range may also increase vehicle collisions. Alteration of habitats by wildfire or development activities may increase moose and deer densities, leading to greater numbers of wolves that may prey on caribou.

Source: http://www.albertacariboucommittee.ca/.