Observations of Wolves Hunting Caribou

Abstract

One of the interesting and unsettled problems about predator-prey relations concerns the degree to which predation is selective of the weak and the sick. Efforts to resolve this issue have suffered from lack of specific data. My husband Cris and I were privileged to watch many attempts of the Alaskan wolf ( Canis lupus ) to catch barren ground caribou ( Rangifer arcticus ). The purpose of this paper is to record some of our observations. We camped in various parts of the Brooks Range of Alaska for 13½ months taking moving pictures of caribou and wolves for the Walt Disney Studio. Headquarters were shifted from time to time but our main base camps were three: first, at Noluk Lake near the head of the Colville River on the north front of the De Long Mountains; next, in the Alatna-Nigu-Killik Pass in the Endicott Mountains; and finally, on the Killik River about 25 miles north of this pass. We were in the field from April 15 to November 1, 1953, and from March 13 to October 14, 1954. During this time we observed only 20 wild wolves. The number was comparatively small, as we saw great herds of caribou—at a rough guess, a hundred thousand, of which thousands must have been repeats. The fewness of wolves may have been partly due to intensive wolf-hunting by the U. S. Fish and Wildlife Service the year of our arrival. Movements of the caribou and wolves .—The caribou of northern Alaska winter mostly on the south side of the Brooks Range where adequate lichen range is available. In the spring they stream north not only through various passes but also, very impressively, in many places directly over the tops of the mountains and along the ridges, to summer in the mountain valleys and on the tundra. At …