UC Riverside

Driven by landscape alteration and the introduction of non-natives through human activities, biotic homogenization is thought to be a significant threat to the survival of endemic taxa. Extensive urbanization in southern California, USA, has converted most of the native coastal vernal pool habitat prompting the conservation of native vernal pool species. Habitat alteration associated with urban expansion in this region has extirpated B. sandiegonensis from the majority of its historical habitat. In some artificial basins within the remaining vernal pool habitat, B. sandiegonensis hybridizes with B. lindahli. Hybrids can be identified through both morphology and newly developed genetic characters (Patel et al. 2017). By using both morphological and genomic hybrid indices, researchers and habitat managers will obtain a relatively holistic perspective on the hybridization process. This not only helps to identify populations where a large-scale introduction of B. lindahli has occurred, but also to perhaps predict the future trajectory of species and hybrid distributions.