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Juniata Scientists Collaborates on Bird Habitat Population Study

(Posted February 19, 2007)

HUNTINGDON, Pa. -- Where do the most diverse populations of birds tend to happen -- in a stand of gorgeous white pine trees or in an exurban habitat (that is, the mix of suburban, farm and rural landscapes seen surrounding many large and small cities)? If you guessed the pine stand, you may be wrong. Sewanee\'s David Haskell and Jonathan Evans, and Juniata College\'s Neil Pelkey have found that urban sprawl brings in more birds. \"These exurban areas -- hobby farms, new large-plot size developments, rural areas -- had a much higher diversity of birds than we expected,\" says Pelkey, assistant professor of environmental science at Juniata. \"When you think about it, good bird habitat contains lots of trees and a wide variety of tree species, with a mix of shrubs, vegetation and food sources on the ground. That is exactly what you see in these communities growing outward from urban areas.\" Pelkey and the two biology professors from Sewanee, University of the South, compared the diversity of bird populations in three environments -- natural forests, tree plantations and exurban areas -- in seven counties along the Cumberland Plateau in Tennessee over two years. The study found that tree plantations had much less bird diversity than either exurban areas or natural forest. The project, which was funded by the Environmental Protection Agency and the U.S. Fish and Wildlife Service, combined field surveys with digital map databases to analyze what species were in specific habitats. The article the three scientists published in the open-access journal the Public Library of Science-ONE stated \"the [government\'s] reports on the status of forests give misleading signals about biological diversity when they include plantations in their estimates of forest cover, but exclude forested areas in which humans live.\" Pelkey says this study will add to the debate about how forests should be managed and how urban growth is planned. The implications for federal forest management policies could mean that current practices, in which some agencies offer subsidies for tree plantations while working legislatively to prevent urban sprawl, may need to be re-assessed. \"The analysis shows that these exurban areas are much more diverse in plant life and wildlife than tree plantations, which in the case of Tennessee are monocultural stands of Southern White Pine,\" Pelkey explains. \"In the exurban area individual landowners are creating their own forested landscape, which by definition will be diverse. Now, if everybody was planting the exact same thing, you would probably notice less bird species.\" The next phase of Pelkey\'s research and data analysis will involve measuring the density of bird populations within the same Cumberland Plateau area. Using Geographic Information Systems (GIS) mapping of the bird population studies, Pelkey will analyze exactly where in the landscape bird populations are the most numerous. \"For any common bird species scientists already know what is good bird habitat, what the next phase of the project will be is to find out what the birds think is good habitat.\"

Contact John Wall at wallj@juniata.edu or (814) 641-3132 for more information.