It is a strange sensation to be woken by the shrieking of seagulls – more so because I am a good hour’s drive from the coast. The sound of the gulls takes me back to childhood holidays in Cornwall and Devon, where the birds were part of the holiday experience and something that sat alongside fish and chips and ice cream in a cone. That the gulls have now become part of my inland soundscape has everything to do with a change in their behaviour.
We have seen a huge increase in the numbers of inland-breeding gulls and a good number of our cities now support breeding colonies of lesser black-backed and herring gulls. While numbers are increasing over much of the UK, there have been declines in the gull colonies of northern Britain and Ireland. The birds here in Thetford are lesser black-backed gulls and this is a species for which we have seen a significant increase in the use of man-made structures, particularly rooftops, for nesting. I suspect that some of the large, flat-roofed, industrial units on the edge of town are being used by these birds.
The numbers of gulls present inland during winter has also increased and mixed flocks, often in the company of black-headed gulls, can be seen on fields and around the many piggeries that have become a feature of the Breckland landscape. On occasion, there are even lesser black-backs in with the black-headed gulls on the river at Thetford.
It is thought that these increases, both in winter and during the breeding season, are linked to a change in the feeding opportunities available to the gulls, coupled with a reduction in the levels of persecution. Increasing quantities of food waste seem to litter our streets and our landfill sites now contain vast quantities of organic waste and kitchen discards, all of which provide access to food throughout the year for these opportunistic birds. During the winter months other gulls may join the local birds from further afield, with some arriving from elsewhere in Europe to winter here. At the same time, some of our birds leave Britain to winter elsewhere: a few lesser black-backed gulls winter as far south as West Africa, underlining just how mobile these birds can be.