Table 4. Model-averaged parameter estimates based on 12 general mixed linear models for nest success of dabbling ducks as a function of country, proportion cropland, pond density, and interactions in the North American Prairie Pothole Region between 1964 and 1995. SE refers to standard error, SD to standard deviation, and t = estimate/SE. Parameters in which t > 1.96 have 95% confidence intervals that do not include 0.

Parameter Estimate SE t
Fixed effects
     Intercept 0.84 0.11 7.52
     Country: Canada -0.37 0.12 -3.18
     Proportion Cropland -0.49 0.17 -2.89
     Proportion Cropland*Country Interaction (Canada) 0.43 0.27 1.60
     Pond Density -0.01 0.01 -1.82
     Pond Density*Country Interaction (Canada) 0.02 0.01 2.66
Random effects SD
     Site(Stratum) 0.004
     Year 0.001
     Residual 0.019