Crows may migrate to our metro suburbs or fly hundreds of miles.
March: roost counts decrease and by mid-month are reduced by 75% or more: from 13,000 to 3500.
April: crows continue to depart and nightly roosts are limited to a few hundred by the end of the month.
May: number reduce to their lowest: a few dozen
May-July: the only crows remaining in the city center appear to be local residents (i.e. downtown is their territory)
Mid-late August- crow numbers roosting downtown increase into the hundreds.
September, October-crowns continue to return to Portland at night. Numbers grow from hundreds to thousands. The pre-roost is spectacular!
Nov-February- Counts observed between 5000-13,000