PARENT SESSION
Organized Oral Session 9: Multiscale advanced raster map analysis for ecosystem health monitoring, assessment, and management in the 21st Century
Organizer(s): GP Patil and W Myers
Monday, August 8, 1:30 PM - 5:00 PM, Meeting Room 511a, Level 5, Palais des congrès de Montréal

The effects of landscape characteristics and scale on duck nest survival in the Missouri Coteau region of North Dakota.

Taper, Mark^*,1, Stephens, Scott^{1, 2}, Rotella, Jay¹, Lindberg, Mark³, Ringelman, James², ¹ Department of Ecology, Bozeman, MT, USA² Ducks Unlimited Inc., Bismarck, ND, USA³ Department of Biology and Wildlife and Institute of Arctic Biology, Fairbanks, AK, USA

ABSTRACT- Nest survival is one of the most important parameters in the population dynamics of grassland nesting species of ducks (Anas and Aythya spp) that breed in the Prairie Pothole Region. Grassland habitats used by these duck species are increasingly threatened by fragmentation, which may alter nest survival. Many studies have attempted to address the relationship between fragmentation and nest survival, however, few studies have examined the influence of fragmentation at multiple spatial scales. Understanding how landscape characteristics at multiple spatial scales explain variation in nest survival will help elucidate the mechanisms influencing nest survival. We examined the relationships between habitat variables and duck nest survival (n 4200 nests) on 18 10.4-km² sites selected across a gradient of landscape characteristics in the Missouri Coteau Region of North Dakota. We evaluated competing models of nest survival that considered combinations of habitat features measured at nest sites, within nesting patches, and at multiple landscape scales. We used generalized non-linear mixed-modeling techniques to model nest survival rates. Information-theoretic techniques were used to select among competing models. Models that included covariates measured at multiple landscape scales were better than simpler models that only included covariates measured at a single spatial scale. Landscape covariates measured at 10.4- and 41.4-km² resulted in the best explanation of nest survival. Nest survival was positively related to the amount of grassland habitat, negatively related to the wetland density, and related to the amount of grassland edge in a quadratic manner with the lowest nest survival at intermediate values of grassland edge. Conservation efforts focused on maintaining duck populations should seek to maintain landscapes with abundant grassland and account for the influence of configuration metrics using GIS analyses.

Key words: multiple spatial-scales, nest survival, fragmentation, ducks