Premium
Efectos de la Fragmentación de Praderas sobre el Éxito de Nidos de Aves en el Centro de los Estados Unidos
Author(s) -
Herkert James R.,
Reinking Dan L.,
Wiedenfeld David A.,
Winter Maiken,
Zimmerman John L.,
Jensen William E.,
Finck Elmer J.,
Koford Rolf R.,
Wolfe Donald H.,
Sherrod Steve K.,
Jenkins M. Alan,
Faaborg John,
Robinson Scott K.
Publication year - 2003
Publication title -
conservation biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.2
H-Index - 222
eISSN - 1523-1739
pISSN - 0888-8892
DOI - 10.1046/j.1523-1739.2003.01418.x
Subject(s) - cowbird , brood parasite , nest (protein structural motif) , predation , habitat fragmentation , grassland , ecology , sparrow , conservation reserve program , brood , biology , habitat , fragmentation (computing) , reproductive success , geography , population , parasitism , host (biology) , demography , biochemistry , agriculture , sociology
Grassland fragmentation and habitat loss are hypothesized to be contributing to widespread grassland bird declines in North America due to the adverse effects of fragmentation on breeding bird abundance and reproductive success. To assess the effects of fragmentation on the reproductive success of grassland birds, we measured rates of nest predation and brood parasitism for four species of birds ( Grasshopper Sparrow [ Ammodramus savannaru ], Henslow's Sparrow[ Ammodramus henslowii ], Eastern Meadowlark [ Sturnella 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 influenced by habitat fragmentation. Nest predation was highest in small (<100 ha ) and lowest in large ( >1000 ha ) prairie fragments. Rates of brood parasitism by Brown‐headed Cowbirds ( Molothrus ater ), however, 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 grassland birds. Maintaining grassland bird populations, therefore, may require protection and restoration of large prairie areas.