A few days on from the successful ringing on Monday, a chance to respond to a few questions people have posted. One thing we’ll certainly consider next year is to use coloured darvic (plastic) rings in addition to the metal rings from the British Trust for Ornithology (BTO). Both types of rings used are very lightweight and have no impact on the birds’ ability to fly or live their normal lives, but coloured plastic rings would make it easier to identify the birds away from the nest once they fledge and disperse. The current arrangement of the metal rings allowed us to identify the young male that was taken into care a couple of summers ago, and was sadly picked up dead subsequently. To find out more about the BTO’s ringing programme, look here . There are some amazing stories that have resulted from all of this, and the good work of the Sorby Breck Ringing Group always results in some fantastic data for the Sheffield Bird Study Group annual report.
Above, for example, is a picture taken by Jeff at St George’s last Sunday (thanks Jeff!). The damage to the primaries on the right wing (how would that have come about??) reveals it’s clearly a different bird to the resident pair. And the streaking that runs down the breast – rather than across it – tells us that it’s an immature bird, one that hatched last spring. It could well be that this is one of the birds that fledged from St George’s last year, though it could also be a wanderer from another nest in the Midlands or Yorkshire. Even at the distance in Jeff’s photo a coloured ring would probably be visible, allowing us to know for sure and mapping the movements of the Sheffield birds.
While I was up St George’s during the ringing, Andy D was on the ground and took a series of great photos, showing Simon removing the chicks from the nest (one by one) and then returning them all together from the bag in the top right image. Simon’s an experienced climber, but even so it gets the adrenalin pumping: rather him than me!
Andy also got some terrific images of the female as she circled the tower, including the one above in dive mode and a couple more below.
Dr Nicola Hemmings of the University’s Department of Animal and Plant Sciences has been examining the unhatched egg and is preparing a report to explain why it didn’t hatch. That will follow soon: her piece in a similar vein last year was fascinating, so don’t miss it!