Since late October, Pittsburgh's winter crow flock has been big and brash in Oakland. At dusk they flood the sky, gathering on roofs and treetops to choose a place to sleep. Last week they roosted in the trees around Pitt's Student Union and the Cathedral of Learning. This got them into big trouble!
Every night pedestrians dodged the "rain" from trees filled with crows and every morning the sidewalks were a slippery crow-poop mess. The crows had to go. But how to convince them?
Last weekend Pitt positioned a loudspeaker on the low roof of the Student Union and played very loud bird distress calls over and over all night. They ran it for five nights, Friday through Tuesday, Nov 8-12.
Most people didn't know it was a recording. In the dark it sounded like birds fighting and dying: a robin in awful distress, an unidentified bird screaming and a peregrine kakking.
Late Saturday night Jason Carson recorded the video above and tweeted me with the question: "What is this? Are the peregrines fighting?"
Initially I was fooled and thought it was real, though it didn't make sense. Any bird suffering that much would have died after the first assault and the noise would not repeat. Then Pat Szczepanski told me she heard it Sunday night at 6pm and it dawned on me. Duh! It's a recording.
Usually crows are not impressed by bird distress recordings. They are way too smart to be fooled for long. Sometimes the only thing that will move them are bird-scare firecrackers like the ones they use at Penn State (click here for videos of Penn State's "crow wars").
Why were a few nights of noise enough to move Pittsburgh's crows away from the Cathedral of Learning? I have a theory and I think it's pretty good.
Crows are afraid of peregrines but they're more afraid of great horned owls. They know Dorothy and E2 live at the Cathedral of Learning and they know peregrines hate great horned owls so they probably figured "The enemy of my enemy is my friend" and they chose to roost at Pitt.
But last weekend there was an awful ruckus and the sound of peregrines defending their home. "Oh my gosh!" thought the crows, "The owl must be here! I hear the peregrines attacking it!"
In the dark Dorothy and E2 swooped low to investigate the noise. "Oh no!" said the crows, "The peregrines are here! Fly away!"
The crows didn't move far but they moved far enough. By Monday evening they were avoiding the trees on campus and roosting instead on the roof of Soldiers and Sailors Hall. Just far enough to avoid the owl and the peregrines. Just far enough that Pitt is happy. Just far enough that the noise has ceased and Dorothy and E2 can get a good night's sleep.
Without real live peregrines at Pitt, the crows would not have been fooled.
(video from Jason Carson on YouTube)