PARENT SESSION
Poster Session #6: Conservation Ecology.
Monday, August 6, 2001. Presentation from 3:30 PM to 5:00 PM. Exhibition Hall

Breeding bird response to landscape patterns along the C & O Canal National Historical Park, USA.

Gates, J. Edward¹, Walters, Steven ¹, Ingram, Dianne², ^{1 2}

ABSTRACT- Variables describing land use/cover within 3-km X 3-km "landscapes" were related to abundance of breeding bird species along the C & O Canal National Historical Park in Maryland and Washington, D.C., USA. Birds were sampled in 1995 and 1998 using point counts spaced 0.54-km apart along the 296.9-km length of the canal towpath. Abundance patterns of most species were similar in both years. Forest-interior species had their highest abundance where the percentage and area-weighted average patch size of forest were the highest, and the length of edge was the lowest. These landscapes were characterized by forest cover >55 %, area-weighted average patch size >250 ha, and total length of edge of all forest patches <150 km. Many forest-interior species had their lowest abundance near the urban centers at either end, where the percentage of development was high; or, in the Hagerstown Valley, where agricultural features made up a high percentage of the landscape. The percentage and area-weighted average patch size of agriculture did have a positive effect on abundance of several shrub-nesting birds. The percentage, area-weighted average patch size, and total number of patches of development had a positive influence on the abundance of many suburban-urban birds. Because the Park ranges from only 30.5 m to 4,053.8 m in width, birds breeding within the Park are at high risk from anthropogenic landscape alterations outside the Park boundary.

KEY WORDS: breeding birds, landscape change, C & O Canal National Historical Park, Maryland