Grant: Discovery Grants Program - Individual

Populations of migratory shorebirds have declined dramatically in the past 50 years. Like other migratory animals, they are especially vulnerable to effects of climate change and habitat degradation because problems anywhere in their range can have wide-reaching negative consequences. Many shorebirds stop at a restricted set of sites, termed staging areas, to rest and refuel before resuming their migration. Understanding how birds use these sites, including movement, habitat use, staging duration and diet, is important when developing conservation strategies. The same is true for their wintering areas in the tropics. In addition to understanding how birds use these sites under normal conditions, we also need to consider the predicted increase in frequency and intensity of storms. In eastern North America, the fall migration season coincides with periods of increased storm activity. These storms can directly affect birds if they are in the process of migrating, and can also have substantial indirect effects at staging sites due to habitat loss or disruption of their food supply. I propose to study staging and wintering ecology of a variety of shorebird species that migrate through Atlantic Canada and continue to South America. Using mist nets, my students and I will capture shorebirds at multiple sites in Nova Scotia and New Brunswick, and in upcoming years in Icapui, Brazil. We will collect measurement data on the birds, blood samples, feathers from juvenile birds, and on some of them we will attach radio-tracking and satellite tags. We will then track movements of the birds within the region and as they migrate. We will relate movement patterns and length of stay to estimates of fattening rate and diet, obtained from biochemical assays of blood samples. We will also estimate breeding origin of juvenile birds using stable isotope analyses of feathers and consider carry-over effects from Arctic stressors to staging sites. Variation in the prey base and availability to birds will be assessed by collecting vertically stratified sediment samples at foraging sites. Samples will be collected at two-week intervals during the fall staging period, and if storms occur, sampling frequency will increase to track effects on birds. In Brazil we will focus on movements of birds between coastal tide flats and highly degraded inland salt extraction ponds. We will quantify habitat needs for birds in the area in collaboration with a local NGO that focuses on conservation and public engagement. Canada hosts a large portion of shorebirds that breed in the western hemisphere, and as such bears a significant responsibility for their conservation throughout their range. The work proposed here will advance that goal by enhancing our understanding of non-breeding habitat use and migratory connectivity in several declining species. In the process we will also train numerous students, preparing them for careers in ecology and conservation.