Temperatures are warming fastest at high latitudes and annual temperatures have increased by 2-3˚ C in the Arctic over the second half of the 20th century. Shorebirds respond to cues on theiroverwintering grounds to initiate long migrations to nesting sites throughout the Arctic. Climatedrivenchanges in snowmelt and temperature, which drive invertebrate emergence, may lead to alack of synchrony between the timing of shorebird nesting and the availability of invertebrateprey essential for egg formation and subsequent chick survival. To explore the drivers andpotential magnitude of climate-related shifts in the availability of invertebrate prey, we modeledthe biomass of invertebrates captured in modified Malaise traps as a function of accumulatedtemperature and weather variables for nine North American research camps in the ArcticShorebird Demographic Network over the years 2010-2012. Our results confirm the importanceof both accumulated and daily temperatures as predictors of invertebrate availability, while alsoshowing that wind negatively affected invertebrate availability at the majority of camps. Ouranalysis suggests that the seasonal timing of invertebrate availability over a geographic rangespanning >3500 km is advancing due to warming temperatures coupled with earlier snowmelt.
