Feeding en route: Prey availability and traits influence prey selection by an avian predator on migration

During animal migration, ephemeral communities of taxa at all trophic levels co-occur over space and time. The interactions between predators and prey along migration corridors are ecologically and evolutionarily significant. However, these interactions remain understudied in terrestrial systems and warrant further investigations using novel approaches. We investigated the predator-prey interactions between a migrating avivorous predator and ephemeral avian prey community in the fall migration season. We tested for associations between avian traits and prey selection and hypothesized that prey traits (i.e., relative size, flocking behavior, habitat, migration tendency, and availability) would influence prey selection by a sexually dimorphic raptor on migration. To document prey consumption, we sampled trace prey DNA from beaks and talons of migrating sharp-shinned hawks Accipiter striatus (n=588). We determined prey availability in the ephemeral avian community by extracting weekly abun..., Predator Diet Sampling
The Marin Headlands hosts the most significant raptor migration flight along the Pacific Coast of North America where migrating raptors funnel and converge before gaining altitude to cross the San Francisco Bay (Goodrich & Smith, 2008). We collected diet data from raptors banded at a raptor migration monitoring station located in the Marin Headlands operated by the Golden Gate Raptor Observatory/Golden Gate National Parks Conservancy in cooperation with the US National Park Service (37.8262°N, 122.4997°W; Fig. 1). Sharp-shinned hawks were lured into the sampling site with rock doves Columba livia, European starlings Sturnus vulgaris, and house sparrows Passer domesticus, then captured in dho-ghazzas, mist-nets, or bownets, and released after banding and processing (Hull & Bloom, 2001).
We collected eDNA samples from the exterior surfaces of beaks and talons of sharp-shinned hawks (n= 588; Fig. 2) during fall migration in 2015 (n=282) and 2016 (n=276) from ..., , # Prey availability and traits influence prey selection by a sexually dimorphic avian predator on migration

During animal migration, transient communities of taxa at all trophic levels co-occur over space and time. The interactions between predators and prey along migration corridors are ecologically and evolutionarily significant. However, these interactions remain understudied in terrestrial systems and warrant further investigations using novel approaches. We investigated the predator-prey interactions between a migrating avivorous predator and ephemeral avian prey community in the fall migration season. We tested for associations between avian traits and prey selection and hypothesized that prey traits (*i.e.*, relative size, flocking behavior, habitat, migration tendency, and availability) would influence prey selection by a sexually dimorphic raptor on migration. To document prey consumption, we swabbed trace prey DNA from beaks and talons of migrating Sharp-shinned Hawks (*Accip...