Importance of Individual Species of Predators on Nesting Success of Ducks in the Canadian Prairie Pothole Region

We followed 3094 upland nests of several species of ducks. Clutches in most
nests were lost to predation. We related daily nest predation rates to indices
of activity of eight egg-eating predators, precipitation during the nesting
season, and measures of wetland conditions. Activity indices of red fox (Vulpes
vulpes), striped skunk (Mephitis mephitis), and raccoon (Procyon lotor)
activity were positively correlated, as were activity indices of coyote (Canis
latrans), Franklin's ground squirrel (Spermophilus franklinii), and
black-billed magpie (Pica pica). Indices of fox and coyote activity were
strongly negatively correlated (r = early-season nests were lower in areas and
years in which larger fractions of seasonal wetlands contained water. For
late-season nests, a similar relationship held involving semipermanent
wetlands. We suspect that the wetland measures, which reflect precipitation
during some previous period, also indicate vegetation growth and the abundance
of buffer prey, factors that may influence nest predation rates.