With the chicks growing rapidly, the window for ringing them was equally rapidly closing – they can’t be ringed when too small and if they’re more than about 20 days old, when they’ve become mobile, there’s a risk that they’ll jump out of the nest box. Members of Sorby Breck Ringing Group (whose Chair gave an excellent talk to Sheffield Bird Study Group last week) arranged to ring the chicks in liaison with Jim and John from the University Estates Dept. and all was set for yesterday morning, which explains the lack of webcam stream for an hour (thanks for seeing to that Ian!).
With a special licence from the British Trust for Ornithology, the Sorby members were able to access the nest with climbing gear, so up the tower it was to go over the top and ring the chicks. Simon went out over the ledge and passed the chicks one by one to Gareth and they were then ringed under Steve’s supervision.
Everything went very smoothly and the chicks were returned to the nest within 10 minutes or so. As a result, they are now both sporting a BTO ring that will allow them to be identified. A small amount of down was also taken to enable DNA identification should this prove necessary at any point. For now, they appear to be two females, both in good health.
While the chicks were being ringed the parents were very agitated and both circled the tower, the male at some height but the female keeping much closer and making passes over us.
It was an unprecedented chance to get some photos from a higher level, including some from above as she banked around to circle.
By the time we were back down on the ground, the female had already landed back on the ledge by the next box and everything very quickly settled back down.
A visit this afternoon confirmed that all was back to normal, with both adults perched on the tower, though out of site from the webcams as they favoured the E side, perhaps to keep out of the stiff wind. In the wind of recent days, the chicks too have been keeping scarce, tucked in the ‘blind’ corner of the nest box and not even visible when the parents bring in a feed, as the female did this afternoon, catching a Feral Pigeon after a stoop behind the buildings opposite the nest. There has been some concern via the blog that the female’s foot is damaged, but it seemed to be in full working order in this episode, though she has been holding it ‘limp’ on the nest at times.
At one point, with both adults on the tower, the female called briefly and then set off, soon followed by the male and they both headed off over the rooftops.
I eventually realised that they had spotted a Buzzard and were on their way to see it off, proof of their fantastic eyesight and their ongoing protection of the chicks from any threats.
So the chicks are healthy, ringed and almost three weeks old – everything seems to be going well. The other two eggs were removed from the nest for analysis to see if we can find out why they didn’t hatch and learn anything more about the pair. With just the two chicks to feed this year, it may well be that they grow more quickly and could be ready to fledge a little earlier than the June 5th date that has seen the first flights in both of the last two years. Over the next week the chicks will start to change their appearance quite markedly, as the first proper feathers were in evidence in their wings when ringing them. All being well, one day they’ll fledge and become expert fliers.
There are a lot of people to thank for making the ringing possible, especially Steve, David, Gareth and Simon from Sorby Breck Ringing Group, as well as Jim, John, Ian and Pete from the University. This whole project continues to be very much a joint effort and we’re fortunate to be able to count on so many talented people ready to share their skills and experience.