Feeding and Breeding

Does feeding birds affect breeding? Yes, says one scientist

Published On Thu Jan 27 2011

The study, published last spring in the journal Oecologia, found “if you supplementary feed birds they breed earlier by a few days,” Dr. Jim Reynolds told the Star.

The study, published last spring in the journal Oecologia, found “if you supplementary feed birds they breed earlier by a few days,” Dr. Jim Reynolds told the Star.

A British study into the effect of extended feedings of birds has found that feeding interferes with a bird’s breeding cycle.

The study was conducted by Dr. Jim Reynolds and a team of researchers at the University of Birmingham.

The study, published last spring in the journal Oecologia, found “if you supplementary feed birds they breed earlier by a few days,” Reynolds told the Star.

The team of researchers also found a reduction in the number of eggs being laid and in the percentage of eggs that actually hatched and produced a baby bird, the ornithologist said.

“As a result of those two (things) when you count little heads in each nest there are less chicks in the brood size of the birds,” Reynolds said.

The team fed blue tits and great tits — similar to chickadees — from March to July in a woodland area near the university over a three year period.

They set up three spots within the area and fed some of the birds a mixture of food made of beef tallow and ground peanuts. Other birds got nothing while another group got peanut cake and meal worms.

The team followed the fledgling birds after they left the nest to see how well they have survived.

“Scientific literature is full of papers which feed over the course of a few weeks. No one has tried to reflect what Mr. and Mrs. Smith do in their backyard (feed for a long time),” Reynolds said.

The long-term implications of their study are still being determined, he said.

So what does this mean for people who love to feed their birds in their backyards?

“We’re not suggesting stopping feeding, not for the minute,” Reynolds said.

“I am suggesting we feed them (the birds) in a more directed way. The only way to do that is to carry on research on how they feed and plot a path from there.”