Oh my! It’s a white weasel in a brown background.
Long-tailed weasels (Mustela frenata), native from Canada to South America, molt twice a year in October-to-mid-November and March-to-April. Those who live in the north turn white, the rest of them stay brown. Here’s what they look like in summer.
On October 30 in Calgary, Alberta, Dan Arndt easily found this long-tailed weasel checking out the scenery near Fish Creek Provincial Park. The weasel had turned mostly white though his back was still pale brown (see below).
Long-tailed weasels are fearless and aggressive, able to kill animals larger than they are, but they’re small enough to fall prey to large mammals, hawks and owls(*). Camouflage is important. Their fur is meant to hide them as they hunt and are hunted.
This weasel turned white right on time but there’s no snow to hide him. The first frost usually occurs in Calgary on September 16 and it snows 3.9″ (10cm) in October, but not this year. The high was 54oF (12.2oC) on the day these pictures were taken.
It’s likely that climate change will change northern long-tailed weasels. They’ll probably still molt in October-to-mid-November but without snow to hide them the whitest ones won’t survive. I expect the population will be browner in Canada a century from now.
In the meantime, this one looks annoyed that he’s attracted attention now that he’s put on his winter coat.
(photos by Dan Arndt)
(*) Long-tailed weasels are 12-14″ long but their tails make up 40-70% of their length. Thus their bodies are only 4-8″ long.
I love that you were able to go into the details of this species, how climate change may affect them, and keep it fun and educational all at the same time! Thanks again for using my photos!
I read your excellent blog often, and almost always learn something I didn’t know. However, I think your suggestion that “climate change” can explain the weather in Canada is not only unsupportable, but kind of political and a turn-off.
Sorry you feel that way, Extraneus. I’m not making a political statement, just writing about what’s observed in Nature.
I agree: Weather is not climate. I did not explain the relationship between weather and climate in the blog but I will do so here.
Weather is what happens in a day: it’s a collection of data points. Climate is the long-range average or trend of those data points.
Scientists observed and collected data on many long-tailed weasels for a long time across their vast range (Canada to South America). Analysis of that data shows that the weasels molt twice a year as described in the blog.
Other scientists have observed and collected weather data for a long time across the vast range of the world. Analysis of that data, comparing year to year, decade to decade indicates the climate is changing in many places including Canada. The words “climate change” are not a political football in Canada. Here’s what Canada says about it.
In reply to Extaneus: I feel you are unable or unwilling to recognize reality. I seldom believe in coincidence. A few changes here and there I will chalk off to coincidence. But I am not blind. I can’t ignore the 4 or 5 100-year storms that keep happening every year or two. I can’t ignore when animal instinct forces them to make changes. Their lives depend on it. I sure can’t ignore roses blooming in my front and back yard on November 17 and I live in Wisconsin. My roses and the weasel coat COULD be coincidence, but common sense tells me I think not.
Karen, I have slightly edited your comment (and corrected the date typo).
They are so cute it’s hard to believe they are so ferocious!