Is it the noise, the amount of artificial lights at night, the local vegetation" We just dont know, she said.
However, researchers are testing several theories.
For one, many of the urban forests were dominated by Amur Honeysuckle plants, an invasive shrub native to Asia that is often used as ornamental plants in urban areas. Honeysuckles often made the understory of urban forests thicker than those in rural areas, which Acadians may not like for some reason.
Rodewald said she and her colleagues are removing the plants in some forests to see if that helps Acadian Flycatchers in those areas.
The researchers are also investigating the role of Brown-headed Cowbirds, a species of birds that lays it eggs in the nests of other birds, including the Acadian Flycatcher. The cowbird fledglings are fed by the host birds, often at the expense of their own young.
This study found that urban flycatcher nests were parasitized by cowbirds more often than nests in rural areas, and a new study hopes to find out why.
The findings suggest that conservation of birds in urban areas may be more complex than many ecologists assumed.
If it was just nest predation that was threatening Acadians, than we would know what to do, Rodewald said. But this suggests we need to get a handle on how birds like Acadian Flycatchers perceive these urban habitats. We need to know what they dont like about urban areas before we can determine what to do.
And the problem isnt just with one species of bird, she said.
So much of the world is becoming urbanized, she said. From a conservation perspective, really understanding how animals respond to urbanization is going to be important for protecting biodiversity.
|Contact: Amanda Rodewald|
Ohio State University