Meeting Abstract
P1-1 Investigating the Foraging Behavior of Two Hybridizing Woodrat Species Klure, DM; Cragun, BJ*; Dearing, MD; University of Utah, School of Biological Sciences, Salt Lake City, UT; University of Utah, School of Biological Sciences, Salt Lake City, UT; University of Utah, School of Biological Sciences, Salt Lake City, UT benjamincragun4@gmail.com
Hybrid zones occur at regions of secondary contact between two closely related taxa. When these hybrid zones occur along an ecotone, interspecific gene flow is often restricted due to selection against hybrids that are maladapted to the preferred habitat of either parental species. Conversely, little is known about the ecology of hybrid zones that occur without an obvious ecotone. For this reason, we studied the foraging behavior of two species of woodrat, Neotoma lepida (desert woodrat) and N. bryanti (Bryant’s woodrat), that hybridize along a narrow secondary contact zone in southern California, USA. This hybrid zone consists of a relatively homogenous desert shrubland dominated by creosote bush (Larrea tridentata). We trapped woodrats across four sampling trips from July 2017 to August 2018 for the collection of hair for 13C and 15N stable isotope analyses. Using these data, we estimated the feeding behavior between woodrats of different ancestries. We found a positive correlation between N. bryanti ancestry and ?15N values, suggesting that there may be differences in foraging behavior between woodrat genotypes. This pattern of enriched ?15N values in individuals with N. bryanti ancestry may be due to differential feeding on plants with higher ?15N values or due to the incorporation of insects as dietary components. We are in the process of disentangling these two possibilities by increasing our sample size of hair samples and with the inclusion of mixing models that incorporate C3/C4/CAM plants and insects as dietary sources. Further investigations into the foraging behavior of these two woodrat species will improve our understanding of the interspecific interactions at this site and on the dynamics of hybridization across contact zones that do not occur at sharp ecological boundaries.