In my backyard this evening, I saw what I can only guess is a weasel. There was a small mammal back by my neighbor's shed, and I thought, "Well, huh, that's a funny looking squirrel." So I got out my binoculars. The animal in question was about the size of a gray squirrel, but with reddish brown fur, larger ears, a longer snout, a thin weaselly body, and a skinny dark tail. Consulting my Kaufman guide to mammals, my best guess is long-tailed weasel (Mustela frenata). I'm not entirely committed to a weasel ID, but I don't know what else it could be. Fisher, marten and mink are all too big (and are also not any more likely to be found in the city), and tree squirrels, ground squirrels, chipmunks, etc. don't have a long weaselly body.
The weasel spent some time poking around my compost pile--although the only weasel-friendly things that could possibly be in there are worms and beetles--then hopped back to a pile of brush and scrap wood behind my neighbor's shed (moving very much like pet store ferrets-- which I am sadly more familiar with than wild weasels--kind of boinging and slinky-like). The weasel made a couple such trips, and I've heard that weasels will sometimes move their den from one location to another, but there is no earthly reason for a weasel to build a den in my compost pile, especially since I'm out there three to five times a week throwing stuff in and stirring it up, and the neighbors are in their yard just a few feet away pretty regularly too.
I went outside to go investigate, and caught only the very briefest glimpse of the weasel as it boinged away, making a cute little trilling chirp as it did. It looks like it was digging in my finished compost pile, the one I haven't added anything to for about a month or two, the one that is covered in volunteer squash sprouts, and there is now a pile of compost on the grass outside the bin, which wasn't there two days ago when I mowed the lawn. I did not see any obvious evidence of a weasel babies or a mouse den, and of course the weasel did not come out and pose nicely for a photo. I tossed some grass clipping over the tunnel it was digging (because that totally weasel-proofs the compost, right?) and went back inside.
I can't recall ever seeing a weasel in the wild before, and from what I am reading now, they are not an especially common thing to see, especially in the city. Sources say they do generally live near a water source, and there is a little blip of a creek across the street (it is mostly underground in pipes). Maybe the weasel got washed down the culvert from upstream (where it is woodsier) and is just refueling with worms in my compost. I will report more details as events warrant. And I should probably share my observations with the neighbors, since they are currently in the process of building a chicken coop off of their shed.