[CT Birds] Crow Roosts

james.bair at snet.net james.bair at snet.net
Tue Jan 19 18:08:09 EST 2010

Dear Lynn:

You wrote:
  Does anyone know of any literature that has inventoried the numbers and ratios?  Especially of the Connecticut roosts?  

Frankly, Lynn, that would be a challenge. There are so many "intermediate" crows that you cannot really pick out visually--you would need to hear their voice. I might be able pick out ten percent or so in a perched flock at either end of the spectrum that would clearly be American or Fish Crows. Maybe someone else could do a little better, but a lot are in between.

Probably the best estimate would be to take figures from a breeding bird atlas. I realize that would be a mere estimate because crow flocks do migrate some, and you also have no guarantee that a crow that nests in a certain area would necessarily roost in the same area. But it might five you a sense of what to expect. Ditto with Christmas counts. (Speaking from experience, those Christmas count numbers are sometimes guesstimates when scanning a large roost. Not unreasonable, but not necessarily exact.)

You also do sometimes have single species flocks. One time a few years ago I was getting gas at the gas station near the Krispy Kreme on Rt. 1 in Milford. (Someone told me just today the Krispy Kreme has closed.) There was a small roost of about fifteen or twenty crows. A few started "quacking," it was winter, so I figured they were Fish Crows. They were all about the same size, so I believe that all of the birds there were Fish Crows. I realize I cannot be 100% sure, but I think that was a reasonable guess.

Jim Bair

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