Peck on someone your own size! How bigger birds rule the roost
IT hasn’t got terrifying talons, a flesh-ripping beak or an enormous wingspan.
But the little sparrow is the biggest bully in the garden – if you’re a blue tit.
Even though there is barely an ounce in weight between them, the sparrow uses that tiny weight advantage to rule the roost over more delicate rivals.
In fact scientists have discovered that size difference – however slight – generally gives an air of superiority when the feathers start flying over the tastiest morsels on the bird table. In the pecking order of garden visitors, bullying house sparrows and greenfinches get the prize bird food such as easy-to- eat sunflower hearts, a study by Exeter University found.
Smaller birds, including blue tits, chaffinches and coal tits, are forced to eat tougher, lower quality seeds. Despite being just two thirds of an ounce (18g) lighter than a sparrow or greenfinch, these smaller birds are forced to peck faster and fly away more quickly to avoid a fight.
Experts say the findings could help design garden bird feeders that would benefit all species. Senior study author Professor Jon Blount said: ‘Our findings show that larger, heavier species get better access to food – so if the aim of bird feeders is to benefit all species, we need to investigate ways to achieve this, such as different mixes of foods and feeder designs.’
It is estimated that three-quarters of homeowners leave out food for wild birds. Working with the British Trust for Ornithology, researchers studied ten types of perching birds at feeders in Cornwall for almost a month. They were able to determine the most dominant birds by recording 816 competitive interactions between species at feeders.
The bullies were generally bigger, including sparrows, greenfinches and nuthatches, and won the best access to popular sunflower hearts. Less dominant smaller birds, including coal tits, dunnocks and chaffinches, more often ended up with harder-to-eat black sunflower seeds.
Bigger birds were able to spend more time at feeders and peck at a lower rate than smaller rivals – which were forced to fly away if they met dominant birds because of the risk of being injured or wasting energy on a fight, the study published in the journal PLOS One found.