stoat

kärppä Mustela erminea, the ermine or short-tailed weasel, a mustelid native to Eurasia and North America, distinguished from the least weasel by its larger size and longer tail with a prominent black tip.
1886, Transactions of the Edinburgh Naturalists Field Club'', Volume 1, http://books.google.com.au/books?id=ikRKAAAAYAAJ&q=%22stoat%22%7C%22stoats%22&dq=%22stoat%22%7C%22stoats%22&hl=en&sa=X&ei=4Tk0U63NJYX3lAWaz4H4Cw&redir_esc=y page 135,

I have never seen Stoats hunt in packs, but it is certain both Weasels and Stoats do so.

In 1953 it was reported that the stoat had increased to a high population level, but that the weasel introduced at the same time had disappeared (de Vos et al. 1956).

European stoats were long ago introduced to New Zealand (along with ferrets and weasels!) in the mistaken belief that they would control the burgeoning populations of introduced rabbits.