Haida ermine

In the Haida language, this species is known as daayáats’ in its brown summer coat and tlag in its winter coat.[6]

The three subspecies of the Haida ermine were originally considered subspecies of the common stoat (M. erminea). However, in 2013, they were recognized as distinct from any other ermine, and a 2021 study further found them to comprise a distinct species. M. haidarum is thought have originated about 375,000 years ago (during the Pleistocene), and is thought to be the result of ancient hybrid speciation between the Beringian ermine (M. erminea) and American ermine (M. richardsonii). The islands are thought to have been glacial refugia during the Last Glacial Maximum, with both species of ermine being isolated on the islands and hybridizing with one another, while the ice sheets separated them from the rest of the world—thus leading to the formation of a new species.[7][8][9][10] It is recognized as a distinct species by the American Society of Mammalogists.[5]

The species is found on a few islands off the coast of British Columbia and southeast Alaska. In Canada, it is found on the Haida Gwaii archipelago in Graham and Moresby islands, while in Alaska it is found on Prince of Wales Island and possibly Suemez Island.[7] It is found in a temperate rainforest habitat.

Aside from genetic differences, M. haidarum can be distinguished from M. erminea and M. richardsonii by its elongated skull.[10]

Three subspecies are thought to exist.[7]

The habitat for the Haida ermine has been intensively reduced over the past few centuries due to old-growth timber harvest in the Tongass National Forest, an important protected area for the species, as well as industrial-scale mining on the islands, which disproportionately affects insular endemics such as M. haidarum. Expanding human populations and increasing tourism may increase the risk of pathogen spillover to M. haidarum, including pathogens common to pets such as canine distemper and parvoviruses, which have negatively impacted other wild mustelids. Due to the rudimentary understanding of the true level of endemism in these northern archipelagos, these threats must be better quantified to protect species from them. The Pacific martens (M. caurina) inhabiting Haida Gwaii also represent a distinct lineage from other populations, indicating that the habitat of the islands may have allowed other distinct species or subspecies to evolve.[7][10][13]