A hardy little rodent of the Arctic, perfectly adapted to one of the harshest environments on Earth. Found across northern Canada, Greenland, and parts of Alaska, this small mammal survives where few others can—on the icy tundra, where winters are long, summers are short, and food is often scarce. It gets its name from the pale “collar” or band of lighter fur that sometimes appears around its neck and shoulders, but its seasonal transformation makes it truly remarkable. In summer, collared lemmings wear a brownish-gray coat that helps them blend with tundra vegetation, but in winter, they undergo a dramatic color change to pure white, becoming the only lemmings that do this.

One of the most fascinating aspects of the Northern collared lemming is its relationship with the boom-and-bust population cycles of the Arctic. Every three to five years, lemming populations explode in number, providing a feast for predators like snowy owls, Arctic foxes, and weasels. These predators’ survival and breeding success often rise and fall with lemming numbers, making the small rodent a keystone species in the tundra food web. When populations crash, predators must turn to other prey, but when lemmings are abundant, they sustain entire ecosystems.

Behaviorally, collared lemmings are industrious and tough. They feed on tundra plants, especially grasses, sedges, and mosses, storing food in burrows to help them through lean times. During the long Arctic winters, they don’t hibernate but stay active beneath the snow in a network of tunnels, where the snow provides insulation from the extreme cold. They dig small chambers for nesting and food storage, creating hidden under-snow communities that allow them to survive months of freezing darkness. When threatened, they may rear up and chatter their teeth in defiance, a surprisingly bold show for such a small animal.

Distribution

Country

Population est.

Status

Year

Comments

Canada

2016

Nunavut, Northwest Territories, Yukon

Greenland

2016

United States

2016

Alaska