Landscape composition, climate variability, and their interaction drive waterfowl nest survival in the Canadian Prairies

Abstract

For upland-nesting ducks that rely on grassland and wetland habitats in landscapes characterized by human alteration and a strongly fluctuating climate, information on how landscape composition interacts with climate is needed to better understand the security of conservation investments and to inform adaptive management in a changing climate. We characterized spatial and temporal variation in a 10-year study of nest survival of five species of upland-nesting ducks at study areas across the Canadian Prairie Pothole Region. We assessed factors affecting nest survival across gradients of landscape composition, climate, and duck density. Habitat characteristics influenced nest survival at multiple scales spanning nest-scale vegetation density to landscape-scale perennial cover abundance, with the relative magnitude of spatial variation in nest survival greater than that of temporal variation in this study. An interaction between climate and landscape composition suggested that intact landscapes can moderate the effects of interannual variation in climate, reinforcing the importance of habitat conservation in a changing climate. Measured nest survival rates ranged from 4.7% to 40.5% and were high enough to sustain duck populations in only 31% of study areas, barring sustained climatic conditions suitable for elevating other breeding season vital rates, suggesting the need for continued investment in waterfowl conservation.