We have an egg!
Although only just visible behind the infamous rock on the grassy ledge, the falcon was incubating for a couple of hours this afternoon. She was showing typical incubation behaviour, sitting very still with her head down and coming into to the eyrie silently. The female has been quite lethargic over the last couple of days, which is good evidence that she was brooding (eggs developing inside her). The egg was most likely laid in the early hours of this morning.
The pair will only start to incubate constantly once the third egg is laid. So although there may be a 2 day gap between the laying of the eggs, the chicks often hatch quite close together, sometimes within a few hours. Incubation over the first few weeks is quite evenly spread between the pair, but the female will take the larger share in the 2 weeks before hatching.
It’s been a busy day at the eyrie today, at around lunch time the female came into land near the pairs plucking post. A minute later the male came into mate with her, which was a noisy if rather quick affair! We can expect the next egg by saturday.
I thought this would be a good opportunity to give you a brief history of the Falls of Clyde pair. The Tiercel is 15 this year and has been breeding at the site since 2000, he is very distinctive with dark cheek patches. By looking at photo’s we can be sure he is the same individual as all those years ago. In 2000 he was aged as 3 by the presence of some brown feathers on his wings and back, sure evidence of a bird in its 3rd year.
During his reign of this prime site, he has managed to fledge 32 chicks. Research has shown that around 30% of fledged young survive to breeding age. So there may be at least 10 of his young alive and well out there. Seen as the aim of every wild animal is to replace its self at least once before it dies, that is pretty good going!
Our falcon is 11, she has been breeding at the Falls of Clyde since 2004. The female was ringed as an adult in 2005 and was aged as 4 in the hand. Her rings clearly identify her as the same individual. In her life time so far the falcon has raised 21 eyasses to the fledging stage.
Tom Wells – Peregrine Protection Officer