Us Brits (yes, IFLScience is British) are well-known for our love of animals, and we certainly seem to have a soft spot for our feathery friends that visit our gardens. More than half of British people feed the birds, and new research shows that UK great tits have evolved longer beaks specifically to adapt to the feeders we put out for them.
"In the UK we spend around twice as much on birdseed and birdfeeders than mainland Europe – and, we've been doing this for some time. In fact, at the start of the 20th century, Punch magazine described bird feeding as a British national pastime," said Dr Lewis Spurgin, from the University of East Anglia, in a statement.
The new study, a collaboration between British and Dutch universities, compared the genetics of great tits in the UK and the Netherlands. The research is published in the journal Science.
Biologists from the University of Oxford have been studying great tit populations in Wytham Woods in Oxfordshire for decades and have a great deal of data to show that the birds’ beaks have gotten longer over time. Many of the birds are tagged, allowing the researchers to see how much they visit birdfeeders.
"Between the 1970s and the present day, beak length has got longer among the British birds. That's a really short time period in which to see this sort of difference emerging," explained Professor Jon Slate from the University of Sheffield.
The beaks of birds from Wytham Woods were compared with those of great tits in Oosterhout and Veluwe in the Netherlands. The researchers looked at the DNA of more than 3,000 birds, trying to spot any differences.
British birds were found to have evolved specific gene sequences similar to those that affect face shape in people. They were also similar to the genes that controlled beak shape in Darwin’s famous finches. So, the scientists concluded that the beaks of great tits in the UK are probably evolving to let them feed from birdfeeders more easily, as the same genetic differences weren’t seen in the Dutch birds.
"We now know that this increase in beak length, and the difference in beak length between birds in Britain and mainland Europe, is down to genes that have evolved by natural selection," said Slate.
The team also discovered that great tits that dine at birdfeeders tended to have the genetic variants for longer beaks. What’s more, British birds with longer beaks were more likely to reproduce than their short-beaked counterparts, but this advantage wasn’t found in the Netherlands.
"It's certainly true that birds who have adapted to better access food will be in better condition generally, and so better able to reproduce and outperform others without that adaptation," Spurgin explained.