Apr 18 2011
Later this week — in as little as 3 to 5 days — the peregrine eggs at the University of Pittsburgh’s Cathedral of Learning will hatch. Dorothy and E2 will be busy with many mouths to feed.
Unfortunately, they’ve been busy with another task as well: defending their territory.
A third adult peregrine, a female intruder, has been showing up at the Cathedral of Learning and trying to challenge Dorothy for the site. Last week we saw at least four challenges.
At lunchtime on Friday Karen Lang and I watched E2 fly in very high above the Cathedral of Learning. Then he dove at an approaching female peregrine who evaded him and flew around the building. E2 did not “kak” or wail but when Dorothy caught a glimpse from her position on the nest she wailed and came off the eggs in a rush. Angry and flapping hard (flapping is a threat display) she chased the intruder out of sight in a matter of minutes.
All was calm for more than three hours. Then while watching the webcam after 5pm, I saw Dorothy leap off the nest again. I looked out my office window and saw peregrines flying around the top of the Cathedral of Learning and E2 came in to incubate the eggs. Another intrusion. Again Dorothy chased the intruder away.
So far Dorothy is victorious. Karen assures me Dorothy is one tough peregrine and will not lose the site this season, but until Dorothy completely convinces the intruder to leave she will have to chase her over and over again.
On the webcam you may notice this when Dorothy leaves suddenly. If you hear her wail and she leaves the nest abruptly, she is chasing away the unknown female.
I am cheering for Dorothy. So far so good.
But no matter what happens — whether Dorothy wins or loses — there is nothing we can or should do about it. We are privileged to observe these birds but they are very different from us and we cannot change them. This is how peregrine “society” works. It’s how they assure that the best peregrines survive.
So watch the webcams for the latest developments. You may see some distraction at the Cathedral of Learning.
Soon the eggs will hatch at both Pittsburgh sites. Here’s my best guess at the hatch dates:
- The eggs at the Cathedral of Learning nest will hatch on or around April 22.
- The eggs at the Gulf Tower nest will hatch on or around April 26.
(photo from the National Aviary webcam at the University of Pittsburgh)