Crows may migrate to our metro suburbs or fly hundreds of miles.
March-April: roost counts decrease and by mid-month are reduced by 75% or more: from 18,000 to 3500.
May: crows continue to depart and nightly roosts are limited to a few hundred by the end of the month.
May-July: the only crows remaining in the city center appear to be local residents (i.e. downtown is their territory or non-breeding adults that come into town at night)
Mid-late August- crow numbers roosting downtown increase to 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 6000-18,000