| Richardson's Collared Lemmings are active 24 hours a day. They are found in tundra, and avoid marshy habitats and forested areas. In winter they develop a long, thick, white coat and forked digging claws on their forefeet, and burrow deep in snow tunnels. In the summer, they use simple burrows with one or two entrances, and dash to the safety of the burrow, or hide under a rock, board, or any other available shelter, if they see a predator. They are vegetarians, eating the green parts of plants, berries, flowers, the roots of plants, and even willow bark. They are known for extreme fluctuations in population size: in a study in Manitoba, Canada, they went from a low of about one adult in a 15-hectare area to 25 adults in one hectare (which works out to 325 adults in 15 hectares) over a three-year period. Populations seem to boom and crash in a three- or four-year cycle.
Also known as:
Richardson's Varying Lemming, Richardson's Hoofed Lemming
Merriam, C.H., 1900. Proceedings of the Washington Academy of Science, 2:26.
Mammal Species of the World