Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Invasive vs. Native Bird Species

22.04.2004


Cornell’s Birdhouse Network Seeks Bird Enthusiasts to Help Monitor the Impact of Invasive Bird Species


Credit: Lang Elliott


Credit: Isidor Jeklin

The house sparrow (above), an introduced species, is displacing bluebirds across North America, including the Eastern bluebird (below). Copyright © Cornell University



In the mid-1800s, little brown birds called House Sparrows were introduced into the United States from Europe to alleviate homesickness for the Old World and because they were believed to control insect pests. Since then, these adaptable birds have made themselves quite comfortable here-spreading their wings across all of North America in vast numbers. Their surging populations have resulted in fierce competition with native birds for nesting sites.

According to 2003 data collected by The Birdhouse Network (TBN), a citizen-science project of the Cornell Lab of Ornithology, House Sparrows account for 43 percent of all competitor species (species that take over nest boxes intended for native birds). And although most nest-box enthusiasts discourage nesting by House Sparrows, the birds still comprise 10 percent of all reported nesting attempts when at least one egg is laid.


What effect is this having on North America’s bluebirds, swallows, and other native cavity-nesting species? “We don’t know,” says TBN project leader Tina Phillips. “There are no long-term studies showing the effect of competition between House Sparrows and our native cavity-nesters. This is one reason why we’re asking everyone across the continent to become part of our nest-box monitoring project. The only way to get answers is to get data, which are provided most effectively by people who monitor nest boxes.”

TBN participants monitor activity inside nest boxes, commonly known as birdhouses, and keep track of data such as egg-laying dates, numbers of eggs and nestlings, and fledging dates. They send their observations to researchers at the Cornell Lab of Ornithology, where the data are combined with observations from across North America, to determine the annual nesting success of cavity-nesting birds.

In the middle of the last century, things were not looking so good for bluebirds. Their populations were seriously declining because of pesticide use, habitat loss-and competition with nonnative species, such as House Sparrows. Today bluebird populations are rebounding thanks to bird enthusiasts who provide nest boxes in their yards, fields, and neighborhoods. Bluebirds benefit greatly from this simple act because, like most secondary cavity-nesters, they are physically incapable of creating their own nesting holes and must rely on preexisting nest sites in order to raise their family.

Phillips points out, however, that simply putting up nest boxes isn’t enough. In order to ensure the long-term future of native cavity-nesters, nest-box owners need to monitor and report what’s going on inside their boxes. Only then will scientists have a true picture of the current status and factors influencing breeding success of native cavity-nesting species.

One thing is known for sure. In head-to-head competition, House Sparrows readily out-compete native species for nesting sites by evicting other nesting birds, destroying their eggs, killing nestlings, and sometimes even killing the incubating female. Adding to the competition is the fact that once a male House Sparrow establishes a territory, he remains there year-round, and starts defending that territory early in the season, often preventing later-arriving species such as bluebirds and swallows from nesting.

House Sparrows are also prolific breeders, raising up to four broods per season (compared to just one or two for bluebirds), and each brood averages four to five eggs. They are expert nest builders, and rebuild nests at a rapid rate. For these reasons, TBN is collecting data for a new Nest-Box Competitor Study, which examines the effect of nest-box competition from invasive species on native cavity-nesting birds. Participants collect information about the competitor species using the nest box, the type of interference, if any, by monitors, and the final outcome of the nesting attempt.

In addition to collecting data, there is more that nest-box monitors can do. TBN recommends several tips to discourage House Sparrows from nesting. These tips include avoiding the use of filler grain, such as milo, millet, or cracked corn, at bird feeder stations-all favored foods of House Sparrows. Since House Sparrows can be common around human habitation, TBN recommends placing nest boxes away from heavily trafficked areas. Another strategy is to plug the entrance hole of nest boxes until the desired species arrives for breeding, in the hopes that House Sparrows in the area have already set up housekeeping elsewhere. Since House Sparrows are not federally protected, experienced monitors also often remove nests or eggs and deploy traps.

“Sometimes the best strategy for dealing with House Sparrows is to not put up a box at all, especially if you aren’t willing to discourage their nesting in favor of native species,” says Phillips. She also adds that to really make a difference for the birds, becoming part of TBN and sharing your observations with researchers is essential. So far, the project has received more than 41,000 nesting records for more than 40 cavity-nesting species. Information, however, is still greatly needed for the new Nest-Box Competitor Study.

Serious birders, beginners, families, classrooms, youth groups-everyone is invited to become part of The Birdhouse Network. A registration fee of $15 ($12 for Lab members) helps offset the cost of running the project. Participants receive a Welcome Packet that includes a beautiful poster of cavity-nesting birds, access to private and public cavity-nesting listservs, an annual subscription to the Lab’s quarterly newsletter BirdScope, and access to an online database where participants can submit, organize, share, and store their nest-box observations. People can sign up by calling the Lab toll-free at 800/843-2473 (outside the U.S., 607/254-2473) or by visiting The Birdhouse Network’s web site at www.birds.cornell.edu/birdhouse.

Nest Box Cams, a Peek Inside the Mysterious Lives of Cavity-Nesting Birds

Since 1999, The Birdhouse Network (TBN) has provided live images of cavity-nesting birds to viewers around the world. Using a system of Nest Box Cams-small cameras placed inside nest boxes-Internet viewers can follow species such as bluebirds, swallows, Barn Owls, American Kestrels, and chickadees, as they build their nest, lay eggs, hatch, feed the young, and much more. Developed and managed by the TBN staff, the cams have attracted nearly half a million viewers. “The cams are a great way to get a close-up-and-personal look at what goes on inside a nest box, something that just wouldn’t be possible without the cams,” says Tina Phillips, TBN’s project leader. To get a peek or to make a donation to support the cams, visit The Birdhouse Network’s web site at www.birds.cornell.edu/birdhouse. To become a sponsor of the cams, contact Tina Phillips at 800/843-2473 or, if outside the U.S. 607/254-2473.

The Cornell Lab of Ornithology is a membership institution interpreting and conserving the earth’s biological diversity through research, education, and citizen science focused on birds.

Allison Wells | Cornell News
Further information:
http://www.news.cornell.edu/releases/April04/TBN.04.amw.html
http://www.birds.cornell.edu/birdhouse

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>