On 20th February we received an exciting email from one of our volunteer gull ringers at Orford Ness: our first GPS-tagged Lesser Black-backed Gull of the year had returned to breed! Since then, other gulls have come to join it, and now 15 tagged birds are back (12 tagged in 2011 and 3 from 2010). Last year all our tagged gulls migrated to wintering grounds in North Africa (see previous article). This year, we've seen some very different movements, with some birds going to Morocco, Spain and Portugal, but others staying in the UK for the whole winter — one individual did not even leave East Anglia!
Lesser Black-backed Gull, Chard Reservoir, Somerset & Bristol (Photo: R G Harris)
These contrasting patterns are beautifully illustrated by our only tagged breeding pair of gulls, which were both fitted with GPS transmitters on 21st May 2011. The male in this pair spent most of his winter in Dorset, Hampshire and Somerset, primarily roosting in and around Poole Harbour. His mate, meanwhile, opted to sun herself in Lisbon. Intriguingly, these birds, which left Orford Ness in late summer, nearly met in late October, when the female was preparing to depart for warmer climes. On the afternoon of 28th, the female called in on Ibsley Water in Hampshire for about half an hour. Less than an hour later, the male was also there, having returned to roost after spending the afternoon on fields near Blandford Forum. However, our female had already left and was on her way south, missing a reunion with her mate by a matter of minutes!
Path taken by individual male (red) and female (yellow) Lesser Black-backed Gulls over winter 2011/12.
These latest results provide a powerful demonstration of just how much more there is still to learn about bird migration. With our Lesser Black-backed Gulls still arriving, and their tags still functioning after more than one winter, we are amassing ground-breaking data in incredible detail that we will analyse over forthcoming months to help us better understand the overwinter movements of this fascinating species.
