CHANGES IN THE SKULL MORPHOLOGY OF THE ARCTIC WOLF, CANIS-LUPUS-ARCTOS, DURING THE 20TH-CENTURY

Measurements of a large series of skulls of the Arctic wolf Canis lupu s arctos, have shown that since 1930 there has been an overall reducti on in the size of the skulls, together with widening of the cranium, s hortening of the facial region, and reduction in size of the teeth. Th is suggests that hybridization and subsequent introgression occurred w ith huskies (Canis familiaris) during the 1930s, which is consistent w ith historical accounts. Since 1950 there has been a reversion in skul l morphology to a more 'wolf-like' form, suggesting that hybridization is no longer occurring. The skull of a wolf/dog hybrid is intermediat e in size between the skulls of wolves and huskies but its shape is al lometrically dissimilar. Skulls of wolves from the period 1930-50 are more similar to the skull of this hybrid than in the other time period s. The skull of a male canid from a carcass collected on Ellesmere Isl and and presented to the Natural History Museum, London, in 1986 was a t first thought to be from a wolf/dog hybrid but analyses of the measu rements show that it is more likely to be from an Arctic wolf with sev ere abnormalities to the jaws.