When you watch a feeding at the Cathedral of Learning peregrine nest you’ll see just one baby now.
As early as Friday morning, only 12 hours after he hatched, I could tell something was wrong with Chick#2. He was noticeably weaker and his movements were odd and uncoordinated. He seemed to have a developmental problem that caused spasms.
The big clue was that he left the nest. This is abnormal and life-threatening behavior in a chick so young. Peregrine nestlings must be brooded by their parents during their first week of life because they can’t thermoregulate yet.
On Friday afternoon Chick#2 literally rolled in a ball out from under Dorothy’s tail.
And here he moved outside Dorothy’s wing in 41 degree weather on Saturday morning. He must be twitching a lot considering the look on her face.
Midday Saturday he moved out of the nest scrape and did not return for feedings. Here Dorothy and E2 seem to confer about him on Saturday afternoon. (He is lying in the shade beyond them.) There was nothing to be done. He was too handicapped to survive.
This leaves just one surviving baby out of five eggs. Until this year Dorothy always raised three to five young per nesting season — but she is 14 years old now.
Her low hatch rate and handicapped chick are both normal outcomes considering her age. Just as in humans, older mothers have fewer babies and are more likely to produce handicapped young.
I am sorry to see this happen because Dorothy is my very favorite peregrine. But the reality is that Dorothy, like all of us, is aging.
The good news is that Chick#1 is healthy and vigorous. He will get lots of attention and education from his very experienced parents.
(photos from the National Aviary falconcam at the University of Pittsburgh)