Feeding birds during winter means healthier hatch in spring

[Animal 0]

p.s. Je crois à cette étude ! Tous les ans, mes petits moineaux ont au moins 3 portées dans chacun de mes nichoirs. Depuis le mois de décembre, ils ont déjà formé leur couple et travaillent sans relâche à solidifier/ aménager les nids de l'année précédente...

-------------------------------------

Feeding birds during winter means healthier hatch in spring
Study links human help to 'breeding success'

TOM SPEARS
Canwest News Service


Wednesday, February 06, 2008


Birds that you feed through the winter will raise bigger and healthier broods next spring, according to the first study to link feeding by humans to "breeding success."

The study from Britain and Ireland focuses on a European type of chickadee - the white-tailed version - but scientists say the findings probably apply to Canadian chickadees, cardinals and blue jays, too.

Birds that had access to feeders laid the same number of eggs as those that had to find all their own food, the scientists found. But the human-fed birds laid eggs earlier, giving their babies a chance to fatten up before all the other bird families are hunting for food. Their young also grew up stronger and healthier. In the end, these families produced one more surviving young bird than the birds left on their own.

A typical nest has about 10 eggs at the start. Bird-lovers in Britain and the United States put out 500,000 tonnes of bird food each year, the study by the University of Exeter and Queen's University Belfast found.

"We have very mild winters, and it probably has a much more substantial effect in places where the winters are hard," such as Canada, said lead researcher Stuart Bearhop of the University of Exeter. But there's a remaining mystery: What part of the food matters most?

"We really don't know whether it's the energy or some other nutritional value," Bearhop said. If the birds just need calories, then anything with fat will do. But it may be that feeders are supplying vitamins and minerals crucial to raising young, such as vitamin E, crucial in egg production and embryo development.

Peanuts and many seeds are rich in vitamin E.


The Gazette (Montreal) 2008