Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Even small patches of urban woods are valuable for migrating birds

Even tiny patches of woods in urban areas seem to provide adequate food and protection for some species of migrating birds as they fly between wintering and breeding grounds, new research has found.

The results are important because, with the expansion of cities worldwide, migrating landbirds increasingly must pass through vast urban areas which offer very little of the forest habitats on which many species rely.

“The good news is that the birds in our study seemed to be finding enough food in even the smaller urban habitats to refuel and continue their journey,” said Stephen Matthews, co-author of the study and a post-doctoral researcher in the School of Environment and Natural Resources at Ohio State University.

Matthews conducted the study with Paul Rodewald, an assistant professor of environment and natural resources at Ohio State.

The researchers published two related studies: one will appear in an upcoming issue of the journal Landscape Ecology and the other appeared in a recent issue of The Condor.

Both studies involved a secretive relative of the American Robin called Swainson’s Thrush (Catharus ustulatus). Swainson’s Thrushes winters mainly in Central and South America, and travel through the eastern United States to their breeding grounds in the boreal forests of Canada.

The researchers captured up to 91 Swainson’s Thrushes at a woodlot on the Ohio State campus while they were migrating through Columbus in May or early June, 2004 to 2007. They then fitted them with tiny radio transmitters and released them at one of seven wooded sites in the Columbus area. (The radio transmitters were glued to back feathers and naturally fell off within a few weeks.)

The sites had forest sizes that ranged from less than one hectare (1.7 acres) to about 38 hectares (93.9 acres) in size.

Using the radio transmitters, the researchers tracked how long the thrushes would stay in the woodlots where they were placed. If they left soon after release, that would suggest that the sites did not provide the food and habitat that they required.

Results showed that at the five largest release sites, all the birds stayed until they left to continue to their migration north. At the two smallest sites (0.7 and 4.5 hectares), 28 percent of the birds moved to other sites in the Columbus region.

“The fact that a majority of the birds stayed at even our smallest sites suggests that the Swainson’s Thrushes were somewhat flexible in habitat needs and were able to meet their stopover requirements within urban forest patches,” Rodewald said.

The study revealed that the birds stayed at each site from one to 12 days, with the average being about four days. There was no difference in how long the thrushes stayed across the seven sites.

“If our study sites differed strongly in habitat quality, we should have seen differences in how long the birds stayed,” Matthews said. “The fact that the stopover duration was similar suggests that all the sites were meeting the needs of the thrushes as they prepared for the next leg of migration.”

The study did find that the later the calendar date, the shorter the thrushes stayed at the sites. That may be because the later-arriving birds would be in more of a rush to reach their breeding grounds, Matthews said.

Weather was also a factor: birds tended to leave the sites when winds were light, following a drop in barometric pressure.

Birds also tended to stay longer if they had lower body mass, suggesting they needed to bulk up more to continue their journey.

While nearly all sizes of woods appeared adequate for the thrushes, they still seemed to prefer larger forested areas, the study revealed.

In one of the studies, the researchers found that in the larger urban woodlots, the thrushes would stay farther in the interior and not get as close to the forest edge. The birds also moved less during a three-day period in the smaller sites, indicating they were more restricted in the area where they could forage for food.

The researchers cautioned that this study was done with just one species, so it is impossible to say whether the results will apply to other species. But the Swainson’s Thrush is one of the more forest-sensitive species, so the fact that it could make do with even small, fragmented woodlots is encouraging.

“These findings suggest that remnant forests within urban areas have conservation value for Swainson’s Thrushes and, potentially, other migrant landbirds,” Rodewald said.

“Obviously, larger forest patches are better, but even smaller ones are worth saving.”

The study was funded by the Ohio Division of Wildlife.

Contact: Stephen Matthews, (614) 247-1889;
Paul Rodewald, (614) 292-9795;
Written by Jeff Grabmeier, (614) 292-8457;

Stephen Matthews | EurekAlert!
Further information:

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: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

TRAPPIST-1 planets provide clues to the nature of habitable worlds

21.03.2018 | Physics and Astronomy

The search for dark matter widens

21.03.2018 | Materials Sciences

Natural enemies reduce pesticide use

21.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>