Spatio-Temporal Patterns in the Depredation of Waterfowl Nests in the Prairie Potholes Region, USA
The Waterbird Society
Nest depredation is the leading cause of waterfowl nest failures in much of the Prairie Pothole Region, USA. In 2006 and 2007, spatial and temporal patterns of nest depredation were evaluated on 248 waterfowl nests and 88 simulated waterfowl nests in North Dakota, USA. The hypothesis that predators are able to locate adjacent nests using an area-restricted search once they find the first nest and that ducks will space their nests apart to reduce this from happening was tested. However, no evidence was found to support either part of this hypothesis or that density-dependent depredation was occurring. This lack of support, along with no relationship between nest density and nest success, indicate that density-dependent depredation may not have been a problem in our study area. Artificial nests were used to test the hypothesis that meteorological conditions impact nest depredation rates. Artificial nests were more likely to be depredated when either temperature or dew point was high. It was hypothesized that these meteorological conditions increase the evaporation rate of odorants, and thereby improve the ability of predators to locate food sources by using olfaction. These meteorological conditions could also increase odor release from the surfaces of nests or incubating hens, although additional studies are necessary to determine if the relationship between evaporation rates and foraging efficiency of olfactory predators holds for natural waterfowl nests.
Borgo, J. S. and M. R. Conover. 2015. Spatio-temporal patterns in the depredation of waterfowl nests in the Prairie Potholes region, USA. Waterbirds 38: 133-142.