Caribou Seasonal Movements

Alaska holds 13 caribou herds; a combined population total of 600,000. They remain a continuous source of meat for Eskimos, Indians, and other dwellers north of the Yukon. However, the expansion of industrial developments and inhabitancy has threatened the future status of this big-game species. Because of this, it’s important to understand the migration patterns of the caribou so they may be better protected.

Throughout the year, caribou remain in constant motion. Though they visit a wide variety of areas, a certain rhythm and pattern is apparent in their movements. These primary movements seemed to be ruled by the seasonal energy needs of the species. Dietary requirements are at its peak during the spring/summer when caribou must fulfill the demands of antler development, calving, lactation, and shedding. The movement patterns reflect this, as caribou progress to areas containing a high abundance of quality vegetation. September marks the species drift towards winter ranges. During the winter months, caribou enter a state of dormancy where there’s a diminished food, growth, and metabolic rate. The four largest herds are described in detail below.

The Arctic Herd

Alaska’s northwestern caribou are known as the arctic herd. They occupy a range of 140,000 square miles north of the Arctic Circle. The primary winter range of the arctic herd lies south of Brooks Range. If the snow conditions aren’t particularly harsh, then the herd will deep into the forest zone. If the conditions are severe, then the herd will remain within the mountain of the Arctic Slope. In March, when spring movement begins, the herd will move to their respective calving grounds up north. This area is located along the waters of Colville, Ketik, Meade, and Utukok. The summer dist5ribution is rather random, with caribou being found anywhere west of the Sagavanirktok River.

The Porcupine Herd

The Porcupine herd scopes over portions of northeastern Alaska, northern Yukon Territory, and Northwest Territories west of the MacKenzie Delta. Their springtime trek includes an area between Old Crow and the Bell River, via low passes to the Blow, Babbage and Firth Rivers. Their major calving location is just south of the Barter Island, roughly between the Katakturuk and Kongakut rivers. Postcalving movements bring the caribou south into the foothills of the British and Romanzof mountains. In the fall, the caribou make the long journey back to Old Crow via the Brooks Range.

The Nelchina Herd

The Nelchina caribou reside in Southcentral Alaska. In late September, these caribou move to lower elevations, making a clockwise swing across the Lake Louise Flat. The main calving movement ranges westward from the Wrangell Mountains, cross the Copper River. The movement continuous through the Alphabet Hills to the foothills of the Talkeetna Mountains.

The Fortymile Herd

Eastcentral Alaska and the Yukon Territory caribou are known as the Fortymile herd. They are the least predictable of the caribou herds, and their winter migration patterns change almost annually. The major ranges include the Ladue River-Sixtymile River area, Canada, and the foothills of the Ogilvie Mountains. Spring movements are directed northwest along the summit of the Tanana Hills.