COLUMBUS, Ohio New research finds fresh evidence that urbanization in the United States threatens the populations of some species of migratory birds.
But the six-year study also refutes one of the most widely accepted explanations of why urban areas are so hostile to some kinds of birds.
Most ecologists have assumed that common nest predators in urban areas such as house cats and raccoons were destroying eggs or killing young birds in greater numbers than in rural areas, said Amanda Rodewald, co-author of the study and associate professor of wildlife ecology at Ohio State Universitys School of Environment and Natural Resources.
But this study was one of the first to actually test that assumption by monitoring natural nests over several years. And the results showed that predators werent the main problem: instead, the birds just didnt seem to like urban areas and gave up more easily.
Urban areas attracted lower-quality birds which, compared to those in rural areas, arrived later in the spring, left earlier in the fall, made fewer nesting attempts and were much less likely to return to nesting spots from year to year.
There is something about these urban forests that strikes the birds as unsuitable, Rodewald said. Even when they try nesting, they are less likely to renest after failure or to return in subsequent years.
Rodewald conducted the study with Daniel Shustack, a graduate student in wildlife ecology at Ohio State. Their findings were published in a recent issue of the Journal of Animal Ecology.
The researchers monitored the nesting success in the Columbus area of Acadian Flycatchers, a migratory bird that is a relatively common summer resident in wooded areas across much of the eastern United States. It winters in Central and South America.
The study involved six years of monitoring 387 nests and 167 breeding pairs of Acadian Flycatchers who lived in 35 forest stands in and around
|Contact: Amanda Rodewald|
Ohio State University