Collections > UNC Chapel Hill Undergraduate Honors Theses Collection > The effects of temperature and greenup on the timing of arthropod abundance and avian migration

Migratory bird species must coordinate their migration and breeding to coincide with a period of peak resource availability in the location where they raise their young. Recent evidence suggests that migratory birds have been responding to climate change at different rates than their arthropod food sources. This can lead to a phenological mismatch, where the timing of resource availability produced by a lower trophic level does not align with the timing of resource need of a higher trophic level. Migratory bird species are unable to feed their hatchlings, inhibiting reproductive success. We characterized the seasonal variation of foliage arthropods over the summers of 2015 and 2016 at the North Carolina Botanical Garden in Chapel Hill, NC and the Prairie Ridge Ecostation in Raleigh, NC. Timing and magnitude of peaks in occurrence varied with arthropod order, year, and survey method. Caterpillars and orthopterans had peaks of greater intensity than combined orders of arthropods that represent “bird food.” Timing of peaks were then compared to spring greenup and temperature. Later greenup corresponded with later arthropod peak occurrence with one survey method at both sites, but this was not true for the other survey method or for arthropod peak occurrence comparisons to temperature. The arrival of some bird species aligned with temperature, greenup, and arthropod peak occurrence. These findings help to improve the characterization of arthropod phenology in future studies, and they also demonstrate the importance of testing a network of phenological variables when considering how communities are affected by climate change.