Effects of Prairie Fragmentation on the Nest Success of Breeding Birds in the Midcontinental United States

Autor: John L. Zimmerman, Scott K. Robinson, John Faaborg, David A. Wiedenfeld, Maiken Winter, Rolf R. Koford, Steve K. Sherrod, M. Alan Jenkins, Dan L. Reinking, Elmer J. Finck, Donald H. Wolfe, William E. Jensen, James R. Herkert
Rok vydání: 2003
Předmět:
Zdroj: Conservation Biology. 17:587-594
ISSN: 1523-1739
0888-8892
DOI: 10.1046/j.1523-1739.2003.01418.x
Popis: Grasslandfragmentation and habitat loss are hypothesized to be contributing to widespread grass- land bird declines in North America due to the adverse effects offragmentation on breeding bird abundance and reproductive success. To assess the effects offragmentation on the reproductive success of grassland birds, we measured rates of nest predation and brood parasitism for four species of birds (Grasshopper Sparrow (Ammodramus savannarum, Henslow's Sparrow/Ammodramus henslowiij, Eastern Meadowlark (Stumella magna), and Dickcissel (Spiza Americana)) in 39 prairie fragments ranging from 24 to >40,000 ha in size in five states in the mid-continental United States. Throughout the region, nest-predation rates were significantly in- fluenced by habitatfragmentation. Nest predation was highest in small ( 1000 ha) prairie fragments. Rates of brood parasitism by Brown-headed Cowbirds (Molothrus ater), how- ever, were not consistently related to fragment size and instead were more strongly related to regional cowbird abundance, being significantly higher in regions with high cowbird abundance. Differences in nest-predation rates between large fragments (54-68% of all nests lost to predators) and small fragments (78-84% lost to predators) suggest that fragmentation of prairie habitats may be contributing to regional declines of grass- land birds. Maintaining grassland bird populations, therefore, may require protection and restoration of large prairie areas.
Databáze: OpenAIRE
Externí odkaz: