Apparently, Herring Gulls have now reached an evolutionary crossroads from which two distinct species will, in time, emerge. It seems to be all to do with diet. Traditionally, seagulls live on the coast and do the things we would expect them to do: catch and eat fish, plus crabs and so on stranded on the beach, nest in cliffs etc. However, many seagulls have found rich pickings on café tables, and in rubbish bins and dumps. These gulls nest on the tops of houses and, even if their young fallout of the nest, they are big enough to be a scary challenge for all but the most hungry of predators. Thus, urban gulls have adapted highly successfully to built up environments and their numbers grow.

The trouble is, seagull courtship rituals are centred around tasty morsels of food regurgitated during their mating displays (yes, they do a lot of regurgitating, see entry for 15th Nov) and when an advance is made between a town gull and a country gull, things go wrong. Country gulls have no idea what to do with the proffered hot dogs, buns, chips and half-eaten sandwiches that form the staple diet of urban gulls, while, frankly, town gulls are crap at fishing. The result is that there are now hardly ever any successful liaisons between the two avian branches and, while at present they remain genetically identical, in terms of behaviour, two distinct tribes have emerged with little or no chance of amorous relations in the future. Evolutionary divergence is only a matter of time.

Bummer.