Fig. 4. Predicted duck production (successful nests/100 ha) in the Aspen Parkland of Alberta, Canada, in relation to nest-site vegetation density (NVEG), field residual cover, and pasture health score (PS), based on the product of the most parsimonious nest density and nesting success models (n = 100 fields and 633 nest-fate intervals, respectively). The covariates residual cover (RC) and PS are correlated across all values (Pearson’s product-moment correlation, r = 0.46, P < 0.01), but the correlation is nonsignificant at PS > 57 (r = 0.19, P = 0.191). The PS values graphed therefore represent the point at which RC and PS no longer demonstrate a correlation (58), and the 90% quantile (85). Values for NVEG are 10% quantile (1.00 dm), mean (2.23 dm), and 90% quantile (4.00).