Feeding birds impact male mating chances

LONDON - Feeding birds can delay their dawn chorus, says new research, which pointed out that the extra food could have a major impact on male mating chances.

Scientists have discovered that the growing trend of providing wild birds with food such as sunflower seeds and fat balls is changing their behaviour.

As well as causing songbirds to delay the dawn chorus by 20 minutes, or skip it altogether, the extra food could have a major impact on male mating chances, the journal Animal Behaviour reports.

“Dawn singing is used to show off to females and keep away competitors, so delaying or skipping song at dawn may have detrimental effects on male chances of paternity,” says Valentin Amrhein, zoologist at the University of Basel, Switzerland, who led the study, according to the Telegraph.

“Our advice is to keep feeding birds in gardens during the winter when it can save lives, but stop feeding by the end of March to avoid the breeding season.”

Around 48 percent of Britain households now provide food for wild birds, according to the researchers.

It began as a way of helping birds survive the winter, but the scientists say birds in urban areas are now often fed well into the breeding season or even all year-round.

The scientists investigated the effects of extra food on the great tit, one of the best-known visitors at garden feeders.

The springtime study compared the dawn song behaviour of birds with and without access to supplied food.

It found 36 percent of the birds with supplementary food skipped the dawn singing altogether - nearly four times the rate of the other birds.

Of those that did sing, the average chorus for fed birds was 20 minutes later than for those without extra food.

Scientists believe birds could become reliant on provided food, making it less necessary to forage early. An alternative theory is that the additional food may attract predators, or rival males, which distract the birds.