INDIRECT EFFECTS OF LOW AMPLITUDE ARVICOLINE CYCLES ON DAILY NEST SURVIVAL OF DUNLIN (CALIDRIS ALPINA HUDSONIA) IN A RAPIDLY CHANGING CLIMATE

The Alternative Prey Hypothesis (APH) states that predators switch to relatively more abundant prey when their main prey is scarce. Arctic lemming population cycles may indirectly affect predation risk on alternative prey such as shorebird nests as they share predators. I examined the indirect effects of arvicoline rodent cycles on Dunlin (Calidris alpina hudsonia) reproduction in Churchill, Manitoba. Using 10 years of field data, the study suggests collared lemming (Dicrostonyx richardsoni) cycles did not influence Dunlin nest success. Meadow vole (Microtus pennsylvanicus) cycles had an interactive effect with arctic fox (Vulpes lagopus) and red fox (Vulpes vulpes) abundance, indirectly affecting Dunlin nest success. North Atlantic Oscillations had a positive effect on Dunlin nest success. The results suggest that subarctic ecosystems are more complex than the High Arctic with multispecies trophic dynamics that can be used to predict the changing landscapes of the Arctic as the boreal forest expands northwards.