The stoat (Mustela erminea), also known as the ermine or short-tailed weasel, is a species of Mustelidae 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 because it does not face any significant threat to its survival. It is nominated among the 100 "world's worst invasive species". The root word for "stoat" is likely either the Belgic word stout, meaning "bold" or the Gothic word stautan, meaning "to push". According to John Guillim, in his Display of Heraldrie, the word "ermine" is likely derived from Armenia, the nation where it was thought the species originated, though other authors have linked it to the Norman French from the Teutonic harmin (Anglo-Saxon hearma). T...