10 December 2013

The crows are still roosting near the University of Pittsburgh’s Chevron building, puzzling the crow watchers and annoying pedestrians.  In years past they always moved the roost to Polish Hill and the Strip District by the end of November.  But not this year.  We’re not sure why.

Maybe the lights are brighter or the location is warmer at Chevron.  Warmth is important!  It’s one reason why they roost together rather than alone.

All night long they perch on the branch tips of large bare trees and jostle to stay warm.  The colder the night, the closer they huddle.  Their social hierarchy determines who gets to be in the warmest central locations.  But they constantly readjust.  Peter Bell has heard them muttering and jostling when he leaves Chevron after dark.

For the next three nights low temperatures will be in the teens. Watch this PBS NATURE video and see how active the crows will be this week, changing places to stay warm.

(video commentary from PBS NATURE’s “A Murder of Crows“)