I grew up in the San Francisco Bay Area. When I was a kid, no one ever saw crows in the coastal areas, only further inland in the Central Valley. Crows are now ubiqitous throughout the suburbs and towns, more numerous than pigeons. The same could be said for wild turkeys and canadian geese. Niether wild turkeys, nor Canadian geese were ever seen anywhere in northern California, and now they seem to be everywhere. Is this a result of climate change, or human population growth, or inner avian navigation systems gone kablooey?
There was something in the paper about this not long ago, and it had to do with the kind of mixed woodland, open areas that suburbia created as being ideal for crows. That is, once the tress planted decades ago became mature.
Oh, and I’ve noticed the same thing. Since about 10 or 15 years ago, crows are everywhere! I live in the South Bay.
Same experience here (Monterey Bay). The crows, I assume, moved westward on their own wing, so to speak, but the turkeys were helped by introduction by hunters. Now they are everywhere. If I had a rifle I would shoot them, they are very tasty.
I’ve never seen Canada geese here. They can be raised domestically but you need a license and to follow some rules including not releasing them into the wild.
As a general rule, birds nesting in areas in which they did not nest before is caused by changes in habitats. Here in Charleston, SC, we have numerous woodstorks nesting that before never ventured much further north than Florida. This is caused by more development in Florida. We have also other wading birds, such as reddish egrets and spoonbills now nesting here. Bobwhites were very common here 20 years ago. Due to change in habitat (development) they are as scarce now as hen’s teeth.
It’s not your imagination. Quoting:
In 1991, Audubon Christmas Bird Counts tallied 17 crows and 54 ravens in San Francisco; 60 crows and 23 ravens in Oakland. The 2011 San Francisco count reported 599 ravens and 566 crows; Oakland had 1,152 crows and 193 ravens.
ETA: Ah, missed John’s link.
[nitpick]“Whence” means “from what place or source,” etc. “From whence” is incorrect.
Good thread, though.[/nitpick]
Crow populations decreased dramatically in many areas of the US around 2000 due to West Nile virus; their numbers have since rebounded. I’m not sure if this has anything to do with what you’ve noticed, however.
Further south, here’s a site that claims that the crow population in Orange County “exploded” in the 1990s.