Dorough, Lauren (2013)
Patterns of activity and diversity of bats at the urban-wildland interface in southern California.
Bachelor of Science, California State University Fullerton, Biological Science.
Advisor: Paul Stapp.
Habitat loss and fragmentation pose a significant threat to bat populations. Urbanization can decrease roosting sites and foraging habitat for many species in southern California. The factors that allow some species to persist in cities and suburban areas, while others decline, are unclear. We used acoustic detectors (Pettersson D240X) to record bat echolocation calls at four sites in the eastern San Gabriel Valley that differed in local site characteristics and the degree of urbanization of the surrounding landscape. Each site was sampled for ten nights between March and August 2012. Using Sonobat software to identify 6,439 calls, we detected eight bat species. Activity of the four most common species differed among sites: Tadarida brasiliensis was recorded at all sites, but was the most active species at two golf courses; Myotis yumanensis was the most common species at a large regional park; and Eptesicus fuscus and Lasiurus cinereus were the most common species at an ecological reserve. Although the reserve had the least bat activity and lowest mean species richness (based on calls), it had the highest species richness after adjusting for the number of calls. Community composition differed significantly between the sites except for the golf courses, which were not different from one another. Our results suggest that bats are abundant in areas of southern California where suitable roosting and foraging habitats are available. Understanding how bats are affected by the loss and fragmentation of natural habitats will aid in regional bat conservation efforts.