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Distinguishing Small Weasels

12-21-18 ermine_U1A8001New England has two small weasels: Long-tailed and Short-tailed.  Both of these predators molt twice a year, from brown to white in the fall, and white to brown in the spring.  The name “Ermine” can refer to either of these two species, but it is most commonly used when referring to the Short-tailed Weasel.

Telling the two species apart can be challenging. Long-tailed Weasels are the larger of the two (head to tail = 12-14 inches), while Ermine are slightly smaller (head to tail = 7-13 inches).  Unless you have both species in front of you, however, their size is hard to assess.  A more helpful distinguishing characteristic is the length of their tail relative to their body length. Long-tailed Weasels have a tail longer than half their body length with a black tip. Ermine have a tail length which is around a third of their body length — it also has a black tip. (Photo:  Ermine (Short-tailed Weasel). Thanks to Sharon and Chad Tribou for photo op.)

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13 responses

  1. Alice Pratt

    They must be fairly elusive…I’ve only seen one…in our woods…recognized it by the up/down wavy way it ran.

    December 17, 2018 at 8:56 am

    • Alice Pratt

      …or maybe it was a mink? …it did look larger than a weasel

      December 17, 2018 at 9:00 am

  2. This reminds me of a winter morning a good many years ago, when I discovered a dead ermine on the floor outside our bathroom door, clearly left there by one of our cats. It was quite stunningly beautiful, and I was taken aback. I called the dad of one of my students – a trapper – and said I had a weird question: Had he ever heard of an ermine coming inside a house. His reply: “Oh yeah, it happens all the time.” (!!!) According to him, they come into a house and live in the walls, where they feed on mice they find there! I thought this was really weird. I put the little corpse into my freezer, and took it into school to show my class of fifth graders. To my amazement, one child said, “Oh yeah, we have one of them that comes out onto our kitchen counter sometimes.” (!!!) And since then, I have also heard of this from two neighbors, so…
    (I’m pretty sure mine was a short-tailed, based on your descriptions, Mary.)

    December 17, 2018 at 9:13 am

    • I’ve known of several instances where house-dwelling wild ermine were excellent mouse catchers!

      December 19, 2018 at 7:47 am

  3. paula kelley

    How about a blog on OPOSSUM? Here in Huntington we have noted them dead o the road and in henhouse. How do they survive our winters with out a heavy coat of FUR? tSuggestions for relocating from hen houses.

    December 17, 2018 at 10:02 am

  4. Tamson

    There’s a long-tailed weasel living under a storage building in the town-owned park in South Freeport, where I take my dog in the winter. I’ve seen it twice, and had a really good look at the tail.

    December 17, 2018 at 10:54 am

  5. Kathy Schillemat

    Is it just me or does that ermine not look very healthy?

    December 18, 2018 at 5:36 pm

    • You’re right, Kathy. It’s not healthy at all. For the first time ever, I posed a recently-killed animal in order to show details I’ve never been able to capture with a live specimen! I won’t be doing it again. Two NC readers, yourself included, were keen-eyed enough to detect this!

      December 19, 2018 at 7:45 am

      • Cindy

        Whoa. Busted. 😁 (Though I do think that is completely legit. 🙂 I had no idea. How did you know, Kathy? The eyes? Fur?

        December 20, 2018 at 7:43 am

  6. Kathy Schillemat

    Yes, the eyes and the fur, and the more I thought about it, the more I realized that it was dead. Thanks for the confirmation, Mary. I don’t have a problem with you showing a photo of a dead animal. We can’t really get a good look at live animals, and death is as much a part of life as anything else. We naturallists take our opportunities for more in-depth study when they come to us.

    How was it killed? Do you know?

    December 21, 2018 at 1:09 pm

    • Yes, a friend’s cat brought it to her back door…already deceased!

      December 21, 2018 at 2:58 pm

      • bill lawlor

        Mary: This is an owl question. During the fall and just the other i saw a large owl 3 ft wing span , tanish color under side of wings, granted my view was on a powerline so could see the bird for a few seconds. The voice is very strong, can easily hear it 2 to 300 yds.Hoot pattern is mostly long and 2 short hoots or just one long strong. I thought of Great horned or great gray. Appreciate your input. Thanks, bill lawlor

        January 8, 2019 at 1:38 pm

      • Hi Bill,
        Your description fits that of a great horned owl. Tannish underwings and a call that is typically a “hoo hoo-hoo-hoo-hoo hoo hoo, with the last two hoots pretty distinctive (although not always present). The wingspread sounds good, too (actually it’s even great than 3′, more like 3 1/2!). Nice!

        January 8, 2019 at 3:27 pm

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