A Difficult but Successful Visit to Burhou, Alderney

I’m just back from a couple of days on Burhou, continuing the study of breeding Lesser Black-backed Gulls breeding on the Islands’ largest colony (c 1,000 pairs). The weather was difficult with cool easterly winds and drizzle cutting short the fieldwork, but we did manage to colour ring another 31 new birds, while also re-trapping four caught previously (three on Burhou and one from Chouet landfill).

I also took the opportunity to record 43 colour-ringed LBBGs on the islet, along with six Herring Gulls. It was particularly pleasing to record ten birds which had been ringed as chicks on the islet in 2009, 2010 and even one from 2011 (a year of virtual complete breeding failure for the gulls). Other surprises were an adult LBBG nesting on the island, which had been ringed in winter in Portugal, and a 2^nd calendar year LBBG ringed at Vest-Agder, southern Norway, and which had been seen migrating back through northern Portugal one week earlier .

This year I am very excited that Vicky Warwick-Evans, who is undertaking a PhD on aspects of the ecology of Northern Gannets and European Shags nesting around Alderney, has extended the work to LBBGs. We trapped ten adults known to be breeding on the island, and fitted them with very small data loggers which will record their positions for five days or so. In this way we hope to learn where the gulls from this very important seabird colony feed. However, to do this we have to be able to recover the tags in a week or so, before they simply fall off and are lost (along with their valuable data).