Grant: Discovery Grants Program - Individual

This proposal describes a research program that identifies factors affecting movement of migratory shorebirds across multiple spatial and temporal scales, through the use of GPS satellite transmitters and small radio-tags from the Motus Wildlife Tracking System. First, HQP will study underlying factors related to partial migration and test three hypotheses about its adaptive significance in American Oystercatchers (Haematopus palliatus) breeding in coastal Virginia, USA. Second, HQP will study the relationship between fall breeding season departure timing and moult at migratory stopover sites in two species who have exhibited greater than 50% decline in the last 50 years (Stilt Sandpiper, Calidris himantopus; Short-billed Dowitcher, Limnodromus griseus). Coupled with this study HQP will study habitat choice during moult, the speed of moult, and the consequences of moult to susceptibility to human disturbances, stopover times, foraging behaviour during stopover, and departure times to principal non-breeding sites. The identification of non-breeding sites for these species will also provide important basic information for conservation planning.   Third, using both existing (from motus.org) and new data from newly tagged individuals during breeding seasons, HQP will examine the influences of weather on breeding season departure timing, migration direction, speed, stopover lengths and final destinations (e.g., carry-over effects). I propose to use ptilochronology as a new (old) tool to examine whether flight feather growth experienced by birds during the non-breeding season can relate to the timing of their subsequent arrival to the breeding grounds, their arrival body condition and reproductive success. If so flight feather growth rate may be a proxy for both energy use during the non-breeding season and quality of those non-breeding sites, As part of this data collection we can also test whether the sexes vary in their flight feather growth rates. Using movement data from both a breeding and a migratory stopover site, HQP will examine the repeatability of movement in relation to both abiotic factors, and food availability and predictability. Finally, through a detailed study of motus.org tracking data, HQP will investigate the relationship of latitudinal displacement of migration, diffuseness of the migratory path, degree to which stopover sites were bottlenecked and associated with that, the degree of dependence on a few sites for refueling, the degree to which species employed long-distance flights (e.g., hop, skip or jump, Taylor et al. 2016), and the generality of their foraging behaviour to population declines in North American shorebirds. This study will use both new data collected on several species at risk in Churchill, MB and older data from collaborative networks. This research program proposes to examine these questions in one sub-arctic location (Churchill, MB) and at two coastal locations (Virginia and South Carolina)