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Social and Behavioral Sciences Commons™
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Articles 1 - 3 of 3
Full-Text Articles in Social and Behavioral Sciences
Proximate And Landscape Factors Influence Grassland Bird Distributions, Mary Ann Cunningham, Douglas H. Johnson
Proximate And Landscape Factors Influence Grassland Bird Distributions, Mary Ann Cunningham, Douglas H. Johnson
USGS Northern Prairie Wildlife Research Center
Ecologists increasingly recognize that birds can respond to features well beyond their normal areas of activity, but little is known about the relative importance of landscapes and proximate factors or about the scales of landscapes that influence bird distributions. We examined the influences of tree cover at both proximate and landscape scales on grassland birds, a group of birds of high conservation concern, in the Sheyenne National Grassland in North Dakota, USA. The Grassland contains a diverse array of grassland and woodland habitats. We surveyed breeding birds on 2015 100 m long transect segments during 2002 and 2003. We modeled …
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 …