Trophic niche differentiation within the adaptive radiation of Hawaiian Tetragnatha spiders

Dr. Susan Kennedy, the Biodiversity and Biocomplexity Unit (Economo Unit)


Title:
Trophic niche differentiation within the adaptive radiation of Hawaiian Tetragnatha spiders

Abstract:
The Hawaiian Tetragnatha spiders are a remarkable and well-documented example of adaptive radiation, with approximately 50 species exhibiting a diverse range of morphologies and ecological affinities. Because these spiders are obligate predators, diet is believed to play a critical role in their ecology and evolution; however, until recently, little was known about the precise composition of their diets. I examine the trophic niche ecology of these spiders in a geographic, evolutionary, and temporal context, using the chronological arrangement of the Hawaiian islands to infer changes in the spiders’ ecological dynamics over time. Working at multiple geographic scales – within a single forest site, among sites on an island, and across three different islands – and using various types of data including web architecture, microhabitat, stable isotopes, and gut content metabarcoding, I characterize the trophic niches of Tetragnatha species and explore the extent to which these niches overlap. Additionally, I present a phylogenetic hypothesis for the entire adaptive radiation, which lays the foundation necessary for analyzing the evolution of ecological traits in this lineage. My work helps to illuminate the role of trophic ecology, and how this changes over time, in the context of adaptive radiation.