Peregrine falcons have been nesting in Chichester Cathedral since 2001 and the RSPB has observed and recorded their progress every year since then. The birds nest in one of the turrets which contains a specially-designed nest box provided by the Sussex Ornithological Society. Traditionally, peregrines would nest on cliff edges, creating shallow scrapes in the ground using no nesting material at all. This leaves them open to the high risk of their eggs rolling off the cliffs and so they have come to realise that cathedrals across the country provide much safer, lower-risk nest sites.
The peregrines are nesting in the turret on the right.
The live webcam has been streaming for several weeks now and the peregrines have laid four eggs. This number of eggs was no surprise as the female laid the same last year and she will always lay the same amount; the number of eggs laid in the first year of breeding determines how many she will lay for the rest of her life. This doesn't necessarily mean that all four will hatch out into nestlings. 2014 saw two of the four eggs hatch but this was likely down to the erratic laying pattern of the female. Normally laying would be completed within a week, with 24-48 hours between each egg, but it took a fortnight for all eggs to finally be laid. This year, however, the laying pattern was much more as it should have been, so for that reason, the hopes are that at least three if not all of the eggs will hatch.
My first day as a Public Events Assistant on the project was unseasonably warm and I was quite thankful to be on webcam duty and spending the day in the cool shade of the marquee. I felt a certain amount of pressure as I know the majority of volunteers involved this year are returning participants and so have plenty of knowledge to share from past breeding seasons, in comparison to my limited knowledge-base and experience. Once I got talking to the public, I felt much more at ease and thoroughly enjoyed sharing the few facts I had with interested parties. I know I'll pick up plenty more as I go along, particularly from listening to other staff and volunteers. I certainly got a thrill out of seeing the expressions of wonder and excitement on the visitors' faces.
Until the eggs actually hatch, there is actually a limit to what we are able to show visitors. The female does the majority of incubation and the male is supposed to bring her food and take over about 15% of the work. This particular pair, however, have been behaving in slight contradiction to this. They have been taking shifts of around four or five hours each on the nest and going off to find their own food. On Wednesday, when I was working there, a wake of buzzards circled high up above the cathedral, riding thermals and showing no interest in the nest site. They were seen off by the female with a few vertical attacks, before she took over brooding at around 11am and spent the next few hours exposed to the direct sunlight and heat of the day. As birds don't have sweat glands and so cannot cool down by releasing moisture as we would, they have to "pant" in order to expel the heat from their bodies and regulate their temperature. The female was panting heavily for the entirety of her shift and I did feel for her, having the task of keeping her eggs warm and herself cool simultaneously! No easy task. When the male eventually returned around 3pm, the sun had moved round and shade had crossed most of the nest box, so he was much more comfortable than his partner and only demonstrated panting for a short time.
The fourth egg was laid on 7th of April so, based on the 28-33 day incubation period, we are estimating hatching will begin around the 5th of May. It's at that point that having a 24-hour live stream of the nest could prove very distracting, particularly when there is work waiting to be done! Here's hoping that all four eggs hatch out.