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Full-Text Articles in Social and Behavioral Sciences
Patch Size And Landscape Effects On Density And Nesting Success Of Grassland Birds, Maiken Winter, Douglas H. Johnson, Jill A. Shaffer, Therese M. Donovan, W. Daniel Svedarsky
Patch Size And Landscape Effects On Density And Nesting Success Of Grassland Birds, Maiken Winter, Douglas H. Johnson, Jill A. Shaffer, Therese M. Donovan, W. Daniel Svedarsky
USGS Northern Prairie Wildlife Research Center
Cumnt management recommendations for grassland birds in North America emphasize providing large patches of grassland habitat within landscapes that have few forest or shrubland areas. These Bird Conservation Areas are being proposed under the assumption that large patches of habitat in treeless landscapes will maintain viable populations of grassland birds. This assumption requires that patch size and landscape features affect density and nesting success of grassland birds, and that these effects are consistent among years and regions and across focal species. However, these assumptions have not yet been validated for grassland binls, and the relative importance of local vegetation structure, …
Nest Parasitism On Constructed Islands In Northwestern North Dakota, Amy L. Zimmerman, Marsha A. Sovada, Tim K. Kessler, Robert K. Murphy
Nest Parasitism On Constructed Islands In Northwestern North Dakota, Amy L. Zimmerman, Marsha A. Sovada, Tim K. Kessler, Robert K. Murphy
USGS Northern Prairie Wildlife Research Center
Parasitism of duck nests can reduce host productivity. We examined effects of nest parasitism on success of host nests found on constructed islands in the Fuller-Big Meadows marsh in northwestern North Dakota from 1994 to 2000. We found 1642 duck nests of 10 species on 25 0.3-ha islands. Nine hundred- seventy (59%) of the 1642 nests were parasitized, of which 87% were parasitized by redheads (Aythya americana). The observed parasitism rate was greater than 50% in four of seven years and was highest in 1997 (81 %, n = 252). Mallard (Anas platyrhynchos) nests tended to …
Evidence For Edge Effects On Multiple Levels In Tallgrass Prairie, Maiken Winter, Douglas H. Johnson, John Faaborg
Evidence For Edge Effects On Multiple Levels In Tallgrass Prairie, Maiken Winter, Douglas H. Johnson, John Faaborg
USGS Northern Prairie Wildlife Research Center
We tested how edges affect nest survival and predator distribution in a native tallgrass prairie system in southwestern Missouri using artificial nests, natural nests of Dickcissels (Spiza americana) and Henslow's Sparrows (Ammodramus henslowii), and mammal track stations. Survival of artificial nests was lower within 30 m of forest edge. Nesting success of Dickcissels and Henslow's Sparrows was lower within 50 m to a shrubby edge than at greater distances, whereas fates of nests were not related to distances to roads, agricultural fields, or forests. Evidence from clay eggs placed in artificial nests indicated that mid-sized carnivores …
Long-Term Declines In Nest Success Of Prairie Ducks, Wendy D. Beauchamp, Rolf R. Koford, Thomas D. Nudds, Robert G. Clark, Douglas H. Johnson
Long-Term Declines In Nest Success Of Prairie Ducks, Wendy D. Beauchamp, Rolf R. Koford, Thomas D. Nudds, Robert G. Clark, Douglas H. Johnson
USGS Northern Prairie Wildlife Research Center
Increased predation on nests of ducks in prairie uplands, as a result of habitat alteration, has been hypothesized to cause decreased nest success and population sizes. We tested whether, and by how much, nest success declined using data compiled from 37 studies conducted between 1935 and 1992 at 67 sites in the Prairie Pothole Region of Canada and the United States. Nest success declined (P = 0.0002) over time, but time explained only 10% of the variation; precipitation (P = 0.79) did not account for additional variation in nest success. Nest success declined at similar (P = 0.13) rates among …