Our love of bird feeders is affecting evolution
Brits love their garden birds, and they’ve been feeding them regularly for about a century. Whether it’s a table, a feeder or a fat ball, birds have a guaranteed meal in thousands of backyards around the country; residents of the UK spend twice as much on bird food as other countries in Europe.
Scientists have been studying great tits (Parus major) – a common European garden bird – in the UK and the Netherlands, and they’ve noticed something peculiar. There are significant genetic differences between the two populations, and one of the noticeable distinctions is that the British birds have longer beaks.
Looking back through previous scientific work and specimens in museums, the researchers observed that not only do the British residents have longer beaks than the Dutch birds – they’re also longer relative to their bodies than UK great tits from several decades ago.
Beaks have evolved to be efficient at obtaining a bird’s main food source – for example, snatching insects, scooping up fish or picking at seeds. The scientists can’t be certain, but they think the changes might have been caused by the British obsession with putting food out for the birds, with great tits adapting to the altered availability of food.
Birds with longer beaks have an advantage when it comes to grabbing seeds and nuts from feeders, with shorter-beaked birds struggling to reach the free meal.
You can read more about the research here: www.science.sciencemag.org/content/358/6361/365
Photo: Darrel Birkett/flickr