Grizzly–polar bear hybrid

A grizzly–polar bear hybrid (also pizzly bear, polizzly, prizzly bear, nanulak, Polar-Grizz, or grolar bear) is a rare ursid hybrid that has occurred both in captivity and in the wild. In 2006, the occurrence of this hybrid in nature was confirmed by testing the DNA of a strange-looking bear that had been shot near Sachs Harbour, Northwest Territories on Banks Island in the Canadian Arctic.

Possible wild-bred polar bear-grizzly bear hybrids have been reported and shot in the past, but DNA tests were not available to verify the bears' ancestry.

Analyses of DNA sequences of bears have recovered multiple instances of introgressive hybridization between various bear species, including introgression of polar bear DNA into brown bears during the Pleistocene.

Occurrences in the wild

With many suspected sightings and three confirmed cases, theories of how such hybrids might naturally occur have become more than hypothetical. Although these two species are genetically similar and often found in the same territories, they tend to avoid each other in the wild. They also fill different ecological niches.