Influences of persistent organic pollutant exposure and ambient air temperature on reproduction in an Arctic-nesting...

The transport of persistent organic pollutants (POPs) to northern areas is leading to changes in exposure for Arctic wildlife. Concurrently, high latitude regions are experiencing rapid rates of climate change, which are expected to accelerate into the future. These simultaneous changes in the Arctic environment are especially a concern for bird populations, many of which have declined in recent decades, yet our understanding of potential effects of contaminants and climate change on incubation patterns and offspring characteristics in Arctic-nesting birds is limited. At three sites across the North American Arctic, we assessed the effects of POPs exposure and changes in ambient temperature on Semipalmated Sandpiper (Calidris pusilla) reproduction and tested the hypothesis that egg contaminant concentrations and nest-cup temperatures alter incubation duration and size of hatched chicks. Our results indicated low levels of POPs in shorebird eggs relative to other Arctic species and highlighted differences in exposure patterns across locations and years. At the nest level, nests that were initiated earlier had incubation temperatures that were positively correlated with minimum ambient temperature. Nest temperature and egg POP levels did not influence incubation duration, and we only found weak support for a negative relationship between egg POP levels and chick mass. Our results suggest potential effects of a changing climate and POP exposure on this Arctic-nesting species, but closer examination of possible interactions between contaminants and climate change is needed to more fully understand risk.