The Falls of Clyde peregrines continue to do well. Both were incubating again today, the female was on for around 6 hours and the male 4, during the time I was observing them. The falcon will always be on the eggs overnight, which is thought to be due to her having a larger brood patch. This is a patch of skin on the underside of the bird with fewer feathers, which has evolved to transfer heat to the eggs. She is therefore better equipped to keep the eggs warm during the coolest temperatures. The tiercel tends to roost away from the nest, often high up in one of the spruce trees.
I have noticed over the last couple of days that both our peregrines have been scraping leaves and earth towards them when incubating. This is likely to be reduce the gap between her feathers and the ground, increasing the height of the sides of the nest hollow. It will be an attempt to seal the eggs in these noticeably cooler temperatures
The falcon returned with prey today to the plucking branch, she hasn’t done this over the past few days. It is possible she has another plucking post away from the breeding cliff, or she stores her catches somewhere out of view of the peregrine watch site. The tiercel went out hunting prior to this but failed to return with anything, so she appeared to be hungry. The prey item she brought in was a pigeon and was plucked and pecked to the bone by our falcon.
The male was calling loudly from the eyrie while she was feeding, but she just continued to eat. Eventually he seemed to get bored of waiting and flew down into the gorge and went out himself. As peregrines don’t leave the eggs unattended for long at this stage of incubation, she quickly stopped eating and appeared to clean her beak very hastily and rushed to the ledge to incubate! I’m not sure why the tiercel was in such a hurry, as he had finished off the pigeon that he stored yesterday just an hour earlier. Maybe he wanted to replace at quickly as he could sense the rain coming…..
Tom Wells – Peregrine Protection Officer