I noticed crows congregating in some fields near me, causing me to wonder if crows migrated in the winter. Some do, but a lot of them stick around our area in Ottawa all winter long. They seem to prefer gathering in large flocks or “roosts” at dusk.
Crows are fascinating – they usually mate for life, and have evolved quite a sophisticated family structure with some siblings remaining with the family to raise the following year’s brood. They use tools and they can recognize individual humans.
When I see them gathering in large numbers in fall and winter I try not to read a sinister omen in these “roosts” or “murders”; but rather one more sign of winter’s approach.