Mar 31 2014
This is a bird who didn’t feel well. Yesterday Dorothy looked ragged, tired and uncomfortable.
On March 20, she laid her first egg of the season and was due to lay her second on March 22, but nothing happened. During the week that followed she often stood over the scrape, looking as if she wanted to lay another egg. Nothing. We all wondered what was going on. Bob Mulvihill of the National Aviary wondered if she was egg bound.
A bird becomes egg bound when she’s unable to pass an egg that has formed inside her. It’s a serious, sometimes fatal medical condition and is more common in older birds than young ones. At age 15 Dorothy is definitely an older bird, two years older than the average life expectancy of adult peregrines.
Saturday night (March 29-30) Dorothy roosted on the nest box roof. At some point she expelled a red splotch on the roof, a yellow splotch on the right edge of the box, and a deflated eggshell on the gravel. When E2 came to visit at dawn all three signs were visible. He was active. She was not moving very fast.
I saw the yellow splotch at dawn and wondered if it was a yolk. When Bob saw the signs below he knew that Dorothy had been egg bound and it was over.
Since egg binding is life threatening, it’s good news that Dorothy expelled the egg. This morning at dawn she was more alert and even picked up and ate the expelled eggshell. (Female peregrines often eat the eggshells of their hatched chicks.)
However this episode is one more confirmation that Dorothy is in poor breeding condition and unlikely to have a successful nest.
I don’t know what will happen next but I can predict with confidence that some day a new female peregrine will arrive at the Cathedral of Learning and we’ll see eggs and baby peregrines again at Pitt.
I don’t know when.
(photos from the National Aviary falconcams at the University of Pittsburgh)