Every winter a murder of crows makes its home along the commercial strip near my house, moving as a group, feeding in parking lots and around dumpsters. At least on cold or stormy nights they nest in the nearby woods, which run right up to the back parking lots of some buildings. I once stumbled upon them on an evening walk, bedding down for the night in two low hawthorn trees, but sadly I had no camera. Today there were an even dozen in this tree by the grocery store parking lot. Crows are territorial, even in the winter when they are not nesting, so although I am no expert in recognizing crows it does seem likely that we have only one resident murder each winter.
I have wondered, watching them, why there aren't more. The food supply seems close to infinite from a crow's point of view, given the sheer number of businesses along this mile-long strip. But I have never seen more than about this number at once. Nor can you count on finding them at any particular place in their territory, about which they constantly roam. Sometimes I go for weeks without seeing them, making me wonder if they spend some of their time in other neighborhoods, or even other cities. They are like illegal immigrants keeping a low profile, always on the move, never wearing out their welcome. And I delight to see them whenever our paths cross.