Factors Affecting Western Snowy Plover Winter Foraging Habitat Selection In San Francisco Bay Ponds PDF Download

Habitat loss and degradation by invasive species is a primary limitation to the recovery of the Western Snowy Plover (Charadrius nivosus nivosus), a federally threatened shorebird that resides on coastal beaches in Humboldt County, California. This habitat threat posed by European Beachgrass (Ammophila arenaria) is often mitigated through dune restoration. Some habitat features altered by restoration (e.g., beach width) may influence plover breeding habitat selection. Further study was needed to determine which physical and social features (e.g., presence of conspecifics) influence plover nesting locations. I evaluated this response of plovers to restoration and identified characteristics that influence nest site selection. In an Information-Theoretic framework, I compared nests (n = 81) and random locations within habitat using logistic regression and Generalized Linear Mixed Models to produce Resource Selection Function analyses and conduct model selection analyses. Plovers nested on wider, less sloped beaches, with greater coverage of natural debris (e.g., driftwood, shells) and more conspecifics than at random locations. Plovers nested primarily (84%) in restored habitats, although this was influenced by one human-restored site with 33% of nests. These findings can guide coastal dune system managers to generate the features in restoration that improve nesting habitat and facilitate survival and recovery of this threatened Snowy Plover population.