February 6, 2008

Extra Food Helps Birds Survive and Breed

Extra food given to birds during the winter may not only help them survive, it also enables them to have a more successful breeding season, according to a new study published by the Royal Society, Britain's de-facto academy of sciences.

Scientists conducted the study in isolated woodland in County Down, Northern Ireland where nest boxes were nailed to trees.

In the control area of the wood, scientists left things unchanged, while in the other part of the wood, the scientists set up wire-mesh peanut feeders, replicating the type and volume of food typically put out in gardens in Britain in winter time, according to AFP.

Birds which lived at the "supplement" site laid their eggs on average 2.5 days earlier than birds at the "control" site.

Both sets of birds produced the same number of chicks, but those of the "supplemental" group were far likelier to survive to the point where they could fly and leave the nest. Nearly 80 percent of the "supplemental" group fledged but the success rate in the "control" group was just over 60 percent.

"The extra food we put out for birds contains fat, protein and carbohydrates, which may make the female bird stronger and more able to produce eggs," one of the authors, Stuart Bearhop of the University of Exeter in southwestern England, told AFP.

"Foods like peanuts and bird seed also include vitamins and minerals which can also produce healthier eggs and chicks."

Britons and Americans put out more than 500,000 tons of food for the birds each year according to an estimate cited in the report.

University of Exeter