Why have great tits grown longer beaks? To crack the bird feeders!
THE beaks of garden birds are getting longer to help them reach the seeds in bird feeders, according to scientists.
Leaving food out for birds to help them through the winter has become widespread in recent decades, and scientists believe that great tits in the UK have developed longer beaks than their European counterparts as a result.
The beaks appear to have lengthened relatively quickly in evolutionary terms – since only the 1970s. This period has seen the rise of garden centres which have encouraged the practice of leaving food out for birds.
Study co-author Professor Jon Slate, from the University of Sheffield in England, said of the findings that were published in the journal Science: ‘That’s a really short time period in which to see this sort of difference emerging.’
Researchers analysed DNA from over 3,000 great tits. After tagging the birds, they found those using feeders were most likely to have genes for longer beaks.
Co-author Dr Lewis Spurgin, from the University of East Anglia, said: ‘It may be the case that having a longer beak allows birds to reach into a feeder and access or break down large seeds, such as peanuts. It could also be that a larger beak is stronger and less likely to get damaged by the types of larger seeds people leave out.’
Dr Spurgin added: ‘It seems reasonable to suggest that the longer beaks among British great tits may have evolved as a response to this supplementary feeding.’
The study follows a talk by biologist Simon Watt at Cheltenham Science Festival earlier this year, in which he said blackcap warblers may be developing longer, thinner beaks to reach seeds in feeders.