Geographic variation in caribou on the Canadian arctic islands

Abstract

Analyses of body, leg bone, skull, and pelage data indicated a cline in the characters of caribou (Rangifer tarandus) from central Boothia Peninsula to the western Queen Elizabeth Islands. The main difference between the skulls of barren-ground caribou (R. t. groenlandicus) on central Boothia Peninsula and the more northerly Peary caribou (R. t. pearyi) was a shorter muzzle in the latter. Pelage tone was markedly lighter in Peary caribou and they were smaller in most body measurements, most notably in the length of long bones. Two major populations of Peary caribou were identified: one on the western Queen Elizabeth Islands (Parry Islands), the other on Somerset and Prince of Wales islands. Differences in skull size and form suggest that each population was composed of two or more subpopulations. The larger and darker R. t. groenlandicus occurred on north-central Boothia Peninsula and the two subspecies and apparent intergrades were present in winter on northern regions of the peninsula. The morphological similarity of Peary caribou on Somerset and Prince of Wales islands is explained by interisland movements resulting in genetic mixing. The same is true for caribou on the western Queen Elizabeth Islands and that population apparently has little genetic interchange with the other.