Monday, 31 October 2011
Thursday, 27 October 2011
We were due to watch ringing sessions at Spurn on Tuesday & Wednesday, but the weather forecast for Tuesday was so bad, that these original sessions had to be cancelled, and the participants were asked if they could manage Wednesday or Thursday instead. Unfortunately, this wasn’t possible for most of those who had registered, but more than 80% generously agreed that their fees could still be donated to the scientific work undertaken by Spurn Bird Observatory Trust (SBOT).
Although the main emphasis of the sessions was to observe the ringing process there was also time to look at birds elsewhere on the peninsula. One of these highlights was provided on Thursday afternoon when a Pallas’ Warbler was spotted in the garden where we were witnessing the ringing. The pm crowd were spellbound as this bird, little bigger than a Goldcrest, was observed flitting among the foliage & hovering as it attempted to pluck insects from the underside of leaves. This was a ‘lifer’ for every attendee, and was also the best view I’ve ever enjoyed – even its pale rump was visible. Sadly, my bigger lens was in the car, I was expecting to photograph birds in the hand, so this beautiful image is provided by Martin Standley from another occasion.
The non-ringing highlight on Thurs am was a Firecrest which was first glimpsed through the crack of my window as it sat on the top of a bush right next to the road. The whole class were then able to see it as it flitted from one Sea Buckthorn bush to another. The bird then disappeared when a Miriam Margolyes look-alike, who had earlier also observed the ringing, and was later to gas her way round the point, turned up.
Unusually, we are able to get decent views of some Fieldfares on most of our visits. These are usually wary birds, especially when a large group is present, but these individuals were relatively confiding – perhaps they were exhausted and hungry, although the photographed bird appears to be alert.
Back to the ringing process – every bird was weighed, such as the Goldcrest below. An average weight of this species is 5.5g – any specimens which weigh less than this are released without being ringed, as it is essential that they forage for food as soon as possible, so they may put on some weight and hopefully will survive. In addition to being ringed and weighed, each bird had its wing measured, and all these details are noted in the records.
The wall of the lab was covered with pictures of star birds ringed at Spurn including: Woodchat Shrike, Great Spotted Cuckoo, Nightingale, and various Warblers amongst others. In one corner of the wall were several strings of graduated rings to fit particular species: the smallest for Goldcrests, and then others for slightly larger passerine species. Rings for more specialised ringing sessions of geese, waders and swans were kept elsewhere. Each ring is stamped with the words “British Museum”, and is given a unique serial number, so it can be traced back to Spurn – if a ring is ever recovered. Despite all the work put in at the observatory literally ringing thousands of birds ever year, only about 1% are ever recovered. Fewer are returned for tiny birds like Goldcrests, but for larger birds, such as swans the percentage which are returned is proportionally higher – people are more likely to stumble across the corpse of a swan than a Goldcrest!
In the morning sessions most of the ringed birds were trapped in a Heligoland trap, which has a narrowing funnel, which the birds are ushered into until they reach a small box at the narrow end and are carefully placed in cotton bags – a maximum of 2 are placed in each bag. These bags are then hung briefly from hooks in the lab before the birds inside are processed – ie weighed, measured & ringed it is possible to age some birds, so this Song Thrush had pale tips to many of its body feathers, which showed it was reared this year. The Robin’s mandible was opened, and when it was yellow inside this was another proof that it was a young bird; while the bird depicted had a dark inside mandible, so was an adult.
The other Friday a woman asked Autumnwatch why so many black-billed Blackbirds had suddenly appeared in her garden. Chris Packham didn’t know, but this was explained when we saw examples of both. Every year the east coast is inundated with thousands of blackbirds from Scandinavia. The young males have moulted into their black body feathers, but their bills have not yet taken on their distinctive golden hues. The priority for these Blackbirds is to conserve their energy for the long migration, and the bills will change colour over the winter. If, and when the birds live to return to Scandinavia in the spring, then they will be resplendent in their yellow bills, as without those they could face rejection by their prospective mates.
Juvenile male migrant Blackbird
The Wednesday am session in particular was dominated by the number of Tree Sparrows being ringed. The weather conditions were perfect for huge numbers of them to head south and more than 300 were ringed on that particular day. Other birds we saw being ringed during the 2 days included Lesser Redpolls, Goldcrests, Redwings, a Brambling, a House Sparrow & a Reed Bunting.
I would like to thank everyone from Spurn Bird Observatory Trust who made these sessions so memorable, especially to Paul Collins who gave of his time, & who explained all the interesting byways of bird migration & who provided plenty of interesting anecdotes; but also to Rael Butcher, Steve Exley, Andy Roadhouse & Barry Spence, and those we met on our travels, such as Geoff Dobbs, and anyone else I may have inadvertently overlooked.
Finally, I am also extremely grateful to those who attended the Spurn ringing session, but especially those who booked on the cancelled Tuesday session, and who were unable to attend any of the re-arranged dates, but who generously agreed that their fees could still be donated to SBOT. Therefore, I would like to single out the donations of: Jan Davie, Jackie Gilbert, Claude Hargreaves, Caroline Hunt, Gordon Kitching, Maureen Moore, Janet Park, Tessa Potter, Brian & Margaret Richardson, Alan & Ann Smith and Linda Terry. Because of their generosity, and those who were able to attend, we were able to raise more than £360 for SBOT!