Meeting Abstract

126-2  Sunday, Jan. 7 10:30 – 10:45  Examining Microhabitat Structure and its Use by Wolf Spiders ROSENTHAL, MF*; KESSLER, B; MEZA, P; ELIAS, DO; University of California, Berkeley; University of California, Berkeley; University of California, Berkeley; University of California, Berkeley malcolm.rosenthal@berkeley.edu

Ecological theory predicts that species will partition their habitat use to limit competition. For terrestrial invertebrates, it is possible that this partitioning will occur at extremely fine scales. Wolf spiders (Lycosidae) are often found in high densities, with multiple species present in overlapping habitats. In this study, we aim to (i) assess the fine-scale complexity of the wolf spider’s habitat, (ii) determine to what degree spiders partition their use of the habitat by substrate type, and (iii) test the role of vibratory communication in substrate partitioning. We conducted a survey of wolf spider species noting the substrate on which each individual was caught, and mapped the locations and overlap of substrates over nine 10m² plots. In the lab, we ran the two most abundant species, Schizocosa floridana and Rabidosa hentzi, in mating trials on the three most abundant substrates (oak, pine, & sand) to test whether mating success varied as a result of substrate type. We found that substrate microhabitat was highly complex, with over ten distinct substrates recorded, and most 10m² plots containing three or more substrate types. 95% of S. floridana individuals were caught on oak or other deciduous litter, whereas 50% of R. hentzi individuals were caught on pine litter, suggesting a significant degree of substrate partitioning. In the lab, however, substrate did not significantly affect mating success in either species, suggesting that these patterns of habitat use are not the result of variation in vibratory communication efficacy.