Vulnerability to global change in the arctic-breeding shorebirds

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Natural selection results in a match between organisms and their environments. In ecological time, this match can constrain adaptation to environmental change but can be relaxed through behavioural plasticity. Arctic shorebirds are diverse in ecology and behaviour and their breeding environments are changing due to climate warming. The objectives of this research program are to document the vulnerability of arctic-breeding shorebirds to biological consequences of a changing climate, including habitat alterations and changes in communities of prey, predators and competitors using a range of species that vary in ecology, behaviour and habitat specificity. We describe four approaches for the five-year research program: (1) We will determine breeding habitat preferences, site fidelity, and fitness of four species of shorebirds at Churchill, Manitoba (Dunlin, Calidris alpina, Whimbrel, Numenius phaeopus; Semipalmated Plover, Charadrius semipalmatus, and Red-necked Phalaropes, Phalaropus lobatus). (2) We will document variation in growth rates of the young as a function of timing of breeding to assess whether chick growth and peak insect productivity are matched or mismatched as a result of climate warming. (3) We will study the interaction between the temperate-zone breeding Killdeer (C. vociferus), a species expanding into the sub-Arctic and the Semipalmated Plover, a sub-arctic breeding species. The sub-arctic breeder is predicted to outcompete the temperate breeder in years with average temperatures, while the reverse is predicted in years with above average temperatures. (4) We will study three shorebird species with contrasting levels of conservation concern at two locations on wintering grounds that vary in the frequency of storm disturbance (e.g., Cuba and Georgia, USA). We will examine the impacts of tidal height on foraging preferences and success. The work is novel and significant in that results will allow identification of general principles for which arctic-breeding shorebird species and habitats are most at risk, and provide evidence of whether behavioural flexibility confers resilience to impacts of a rapidly changing environment.