Meanwhile, neighboring caribou herds not subjected to moose control continued to decline.

During that time, though, they exist in huge numbers and can take up to 300 ml of blood per day from each animal in a caribou herd.

Wolves, grizzly, black bears and many members of three different caribou herds range over the refuge.

Several studies show that grizzly bears may follow the caribou herds year-round in order to maintain their food supply.

Caribou herds can be classified as a northern mountain woodland ecotype.