British Birds Have Grown Bigger Beaks! Here’s Why
Here at Boxwild, we’ve been selling our bird seed and gifts for bird lovers for some time now. But it seems bird feeders going back all the way to the 1970s could be responsible for an unusual change in the nation’s bird anatomy.
Scientists from Oxford University, Sheffield University and the University of East Anglia along with experts in the Netherlands are responsible for research recently published in the American journal Science. In a long-running study, from the 1970s to the present day, they looked at beak length and DNA in great tits, comparing birds living in the UK and the Netherlands.
They found that British great tits, over the past forty years, have grown a bigger beak. And, what’s more, they’ve discovered that this change can be attributed to changes in the birds’ DNA. It’s just a 0.3mm difference but, in evolutionary terms, that’s huge. “That’s a really short time period in which to see this sort of difference emerging,” says Jon Slate, professor in animal and plant sciences at the University of Sheffield and co-author of the study.
So how has such a massive change come about?
The Bird Feeder Effect
We already knew that feeding garden birds aids their survival through food shortages and improves their chances of fledging young. It’s thought that leaving food out for goldfinches has reversed the species’ decline. And, as farmland birds have been forced out of natural habitats, birdseed in gardens has provided a much needed lifeline. But now it seems like bird seed is such an important food source for birds that they may have adapted to make the most of it.
One of the theories put forward by the research team for the growth in beak length centres around the very British passion for bird feeding. The British spend twice as much money on birdseed as they do in the Netherlands. It seems that in order to maximise their access to the food within bird feeders, the great tit beak has grown longer.
With the use of radio-frequency tags, the scientists have shown that the longer-beaked great tits do indeed make better use of bird feeders than those with the short-beak gene variant. They have greater access to reliable food sources and are more likely to stay healthy through the breeding season. Research has backed this up further by showing that the longer-beaked great tits, on average, fledge more chicks.
There’s still much to discover about the link between bird feeders and the great tit’s growing beak but it’s undoubtable that feeding birds has had a direct and positive effect on their fortunes.
- Tags: feeding birds
- Nikki Boxwild