Featured Research

from universities, journals, and other organizations

Birdfeeders Can Both Help And Harm Bird Populations

Date:
April 7, 2008
Source:
Ecological Society of America
Summary:
Millions of people tend birdfeeders in their backyards each year, often out of a desire to help the animals. But a new survey of research on the topic finds that feeding may not always bring a positive outcome for the birds.

Attractive feeders can become ecological traps, encouraging birds to settle in an area that cannot support them once supplemental feeding has stopped.
Credit: iStockphoto/Andrew Howe

Millions of people tend bird feeders in their backyards each year, often out of a desire to help the animals. But a new survey of research on the topic finds that feeding may not always bring a positive outcome for the birds.

In many cases, bird feeding was shown to have immediate positive outcomes. A number of studies indicated, for example, that chicks which were given supplemental food were far more likely to fledge than those that were not given extra food.

But feeding is a complex business and can lead birds to make poor decisions later in life. Attractive feeders can become ecological traps, encouraging birds to settle in an area that cannot support them once supplemental feeding has stopped. In those cases, feeders create a population level that cannot be sustained by natural levels of food.

There are also times when feeding can affect the timing of a bird's life in unexpected ways. One study, for example, showed that Florida scrub jays breeding in suburban habitats with access to supplementary food breed earlier, but find themselves out of sync with natural food items which are important when rearing nestlings. This means the extra food can lead to a decrease in breeding success rather than an increase.

Surprisingly, the research team also found evidence in several studies which indicated that the flurry of activity caused by bird feeding does not increase the birds' risk of predation. Counter-intuitively, the presence of feeders has been associated with lower levels of predation by domestic cats.

Robb and Bearhop say that the wide variety of outcomes they discovered in their work point to a real need for more comprehensive research on the topic. Although bird feeding itself may seem somewhat marginal, an incredible number of people do it. Surveys conducted in the US in 2003 revealed that more than 43 percent of those asked give birds some kind of food. In the UK, surveys indicate that as much as 75 percent of the general public feeds the birds.

"Changing the natural dynamics of food supply at such a large scale represents a major intervention in the ecology of birds," says Robb. "But we have a remarkably limited understanding of the impacts of bird feeding."

There have been relatively few studies conducted which incorporate urban and suburban yards, for example, and very few studies have run for more than one or two years or considered more than one species. Robb and Bearhop plan to continue their investigations at field sites in Northern Ireland and Cornwall.

"It seems highly likely that natural selection is being disrupted," Robb says.

Published as a Frontiers in Ecology and the Environment e-View paper the meta-analysis led by Gillian Robb (Queen's University Belfast, UK) and by Stuart Bearhop (University of Exeter, UK) reviewed results from more than 50 pieces of research conducted over the last decade.


Story Source:

The above story is based on materials provided by Ecological Society of America. Note: Materials may be edited for content and length.


Cite This Page:

Ecological Society of America. "Birdfeeders Can Both Help And Harm Bird Populations." ScienceDaily. ScienceDaily, 7 April 2008. <www.sciencedaily.com/releases/2008/04/080403104353.htm>.
Ecological Society of America. (2008, April 7). Birdfeeders Can Both Help And Harm Bird Populations. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2008/04/080403104353.htm
Ecological Society of America. "Birdfeeders Can Both Help And Harm Bird Populations." ScienceDaily. www.sciencedaily.com/releases/2008/04/080403104353.htm (accessed July 25, 2014).

Share This




More Plants & Animals News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Dogs Appear To Become Jealous Of Owners' Attention

Dogs Appear To Become Jealous Of Owners' Attention

Newsy (July 23, 2014) A U.C. San Diego researcher says jealousy isn't just a human trait, and dogs aren't the best at sharing the attention of humans with other dogs. Video provided by Newsy
Powered by NewsLook.com
Professor Creates Site Revealing Where People's Cats Live

Professor Creates Site Revealing Where People's Cats Live

Newsy (July 23, 2014) ​It's called I Know Where Your Cat Lives, and you can keep hitting the "Random Cat" button to find more real cats all over the world. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins