Largest home range (land mammal)

The largest indigenous home range of any land-based mammal belongs to the polar bear (Ursus maritimus). For example, in a paper published in the Canadian Journal of Zoology in 2006, Parks et al showed that adult female polar bears in Hudson Bay, Canada, have home ranges larger than 100,000 square kilometres (38,610 square miles) – three times the size of Belgium. A more recent study published in Polar Biology in October 2014, using tracking data collected between 2004 and 2012, suggests it's even larger. McCall et al put the mean average polar bear range in the Hudson Bay area at 353,557 square kilometres (136,509 square miles) – about the same size as Germany.

A home-range is defined as the area where animals typically eat, sleep and interact.

Polar bears can also cover vast distances in the water; research conducted by the US Geological Survey published in 2012 documented 50 long-distance swims (>50 kilometres; >31 miles) by 20 adult female polar bears in the Beaufort Sea in 2004–09. Swims ranged from 53.7 to 687.1 kilometres (33.3 to 426.9 miles) – mean: 154.2 kilometres (95.8 miles) – and lasted from 0.7 to 9.7 days (mean 3.4 days).