Arthropod Phenology as a Component of Birds' Reproductive Success (2016)

Undergraduate: Tracie Hayes

Faculty Advisor: Allen Hurlbert
Department: Biology

---

Migratory bird species are especially sensitive to climate change as they must time their migration, breeding, and raising of young to coincide with a period of peak resource availability in a distant location, when the climatic cues they use may no longer be reliable. Recent evidence has suggested that birds have been responding to climate change at different rates than their food resources, leading to phenological mismatches across trophic levels with negative consequences for avian reproductive success. I characterized foliage arthropod phenology over summer 2015 using visual and beat sheet surveys at two field sites in North Carolina. From this data, mean arthropod abundance and biomass were calculated, and differences were characterized. Lepidoptera larvae (caterpillars), Orthoptera (grasshoppers, crickets), and Auchenorrhyncha (leafhoppers, planthoppers) had the most noticeable peaks across survey methods and field sites, while orders such as Araneae (spiders) did not show a substantial peak. What this means for insectivorous birds varies based on: (1) how prone a species is to changes in timing of migration and breeding and (2) the specificity of diet needed for hatchlings and fledglings. The peak calculations are important for informing continued data collection over larger geographic ranges. In future work, the timing of arthropod abundance and bird reproductive behavior can be studied spatiotemporally together and in relationship to temperature and spring green-up.