Caribou typically undergo seasonal migrations between summer calving grounds, mosquito-relief areas and winter foraging sites, with migration distances varying amongst herds. In the CYR study area, the larger, arctic herds, undergo seasonal migrations of distances up to 640 km, with annual movements of some caribou totaling more than 5000 km; while the smaller, more regional herds farther south, tend to undergo much shorter seasonal movements. Wider ranging herds include the Western Arctic, Central Arctic and Porcupine herds. The more localized herds include the Fortymile, Galena, Hodzana Hills, Macomb, Ray Mountains, White Mountains and Wolf Mountain herds. The Western Arctic herd has the largest range and most extensive migrations [...]