The stoat (Mustela erminea), also known as the ermine or short-tailed weasel, is a species of Mustelid native to Eurasia and North America, distinguished from the least weasel by its larger size and longer tail with a prominent black tip.
Its range has expanded since the late 19th century to include New Zealand, where it is held responsible for declines in native bird populations. It is classed by the IUCN as Least Concern, due to its wide circumpolar distribution, and the fact that it does not face any significant threat to its survival. It is listed among the 100 "world's worst alien invasive species".
