| The nesting success of Ovenbirds (Seiurus aurocapillus ), Wood Thrushes (Hylocichla mustelina) and American Robins (Turdus migratorius) was investigated in 16 fragmented woodlots (10--56 ha), between 2000--2002. Woodlots were divided into three treatments; intensive agriculture (>42% row-crops and hay in a 2 km radius), less-intensive agriculture (<46% row-crops and hay and 16% old-field and pasture in a 2 km radius) and exurban (≥9 houses within 100 m of woodlot edge). Ovenbird nesting success was lowest in the intensive agriculture treatment, due to high nest predation rates, possibly caused by high abundances of small rodents (Peromyscus spp., Blarina brevicauda, Microtus spp.). American Robin nesting success was lowest in the exurban treatment (P < 0.1) due to high nest predation rates. Wood Thrush nesting success was not related to matrix land-use, however, as the amount of edge per unit area increased Wood Thrush nest survival decreased (P < 0.05, adj R2 = 0.37) and the rate of brood parasitism at Wood Thrush nests increased (P < 0.001, adj R2 = 0.72). The less-intensive agriculture treatment supported potential source populations of all three species. The preservation of woodlots with low proportions of edge habitat in a matrix of less-intensive agriculture will benefit bird populations in fragmented, agricultural landscapes. |
