Field Event Reports

Friday 7 July: Sand Martin Ringing at Radley Lakes

Leader: George Candelin (Keeper of Swifts, Museum of Natural History, University of Oxford)

George Candelin led the ringing session

A group of 10 AbNats members and a visitor gathered on the fine evening of 7th July at the Tuckwells Aggregate site (OX14 3NG), Thrupp Lane, Radley Lakes, where we were greeted by a group of six registered bird ringers and helpers, including George Candelin, who were already unloading their gear. The setting was somewhat surreal for a wildlife encounter - the immediate surrounds were bare earth punctuated by piles of sand and ballast with stark industrial buildings behind (more akin to a set from Dr Who than a wildlife site). Indeed the target of our visit was a bare elongated mound of sand, which from our immediate view was devoid of life. However, on the side away from us there was a buzz of Sand Martins, whose nests were located in the side out of our view. Many Sand Martins were flying around above us so the hopes were high for a successful session.

Around 7.30, the ringing team set up a mist nest against the bank and immediately a dozen or so Sand Martins were caught as they they flew out of the nest holes. The ringers sprung into action, extracting the birds from the net and bringing them back to the cars. The birds were ringed, weighed and measured, sex determined and probable age assessed, all details carefully logged. Quickly and efficiently the birds were released without harm.

There was then a considerable lull of well over an hour before any more birds were caught. While the birds came and went above us, none tried to enter the nest holes, until we all moved back a bit. Four or so birds were caught just before 09.00 and then another batch around 09.15. The ringers seemed reasonably satisfied with the evening's haul.

The session was best described as 'informal' in that we did not have a single dedicated presentation. Rather we all interacted with the individual ringers throughout the evening as they worked (or while waiting for the birds to be netted). They talked us through the procedures and gave informative answers to the numerous questions asked. The differences between adults and newly fledged birds was shown and how to determine the sex by looking for the bare brood patches of the females' breasts. We all also had the opportunity to hold and release these tiny and exquisite birds. In all over 40 birds were caught and 31 ringed - the difference in numbers was caused by some birds being caught twice in the evening!

As dusk approached the nets was taken down and the group dispersed around 9.30. Thanks were conveyed to the ringing team for a highly informative and stimulating evening.

Report: Graham Bateman

Graham Bateman, Margaret Abel, Barry and Beryl Stayte, Sally Gillard, Cynth Napper, Hugh and Vivienne Summers, David Guyoncourt, Adrian Thorn, Matthew Beesley (visitor)