London, Jan 9 (ANI): A new study has revealed that the growing phenomenon of feeding wild birds with food such as sunflower seeds and fat balls is altering their behaviour.
It has also resulted in 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.
"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," the Telegraph quoted Valentin Amrhein of the Zoological Institute at the University of Basel, Switzerland, who led the study, as saying.
"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," he said.
In the study, scientists investigated the effects of extra food on the great tit, one of the best-known visitors at garden feeders.
It found 36 per cent 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.
"The dawn chorus is thought to be a sign of male quality. High-ranking and older males usually start singing earlier in the morning, and earlier starting males have more mating partners, so supplementary feeding should have led to an earlier not later start of singing," said Amrhein.
The findings were published in the journal Animal Behaviour. (ANI)