|Bat Inventories in San Diego County|
In 2002, the US Geological Survey began a series of bat inventory studies in San Diego County funded by several federal, state, and local agencies including the National Park Service, United States Forest Service, California Department of Fish and Game, and the County of San Diego. Four study areas are being surveyed including the Cabrillo National Monument, Descanso district of the Cleveland National Forest, Santa Ysabel Ranch Preserve, and the Multi-Species Planning Area (MSCP) of eastern San Diego County.
Several survey methods are being utilized to conduct these bat inventories including 1) use of mist-nets to capture bats at foraging and roosting sites, 2) use of hand-nets to capture bats at day and night roosts, 3) use of acoustic techniques including Anabat bat detectors and audible listening to detect bats at foraging and roosting sites, and 4) use of artificial lights to visually inspect for bats at roost sites and to visually observe foraging bats. Most of the survey effort has occurred from May through September, however, surveys are being conducted year-round with a reduced but consistent, almost weekly, effort throughout the fall, winter, and spring.
As of February 1, 2003 a total of 17 of the 23 bat species known from San Diego County have been detected during the USGS bat inventory studies. Thirteen of these 17 species have been documented by capture at roosting and/or foraging sites, with the remaining four species having been detected only acoustically.
Photo courtesy of Merlin D. Tuttle © Bat Conservation International.
|Click on a common name in the table below to see images (photos or sonograms) of the species that have been detected during these studies. Photos on the web pages for the various species below were taken by Drew Stokes and Cheryl Brehme of USGS unless otherwise noted.|
|Common Name||Scientific Name||Status1||Detected 20022|
|Phyllostomatidae (American Leaf-nosed Bats)|
|California leaf-nosed bat||Macrotus californicus||CSC,FSS,BLM||A,V|
|Mexican long-tongued bat||Choeronycteris mexicana||CSC||V|
|Lesser long-nosed bat||Leptonycteris curasoae||FE||Not Detected|
|Vespertilionidae (Mouse-eared Bats)|
|Little brown bat||Myotis lucifugus||none||Not Detected|
|Yuma myotis||Myotis yumanensis||FSC,BLM||A,C,V|
|Long-eared myotis||Myotis evotis||FSC,BLM||A,C,V|
|Fringed myotis||Myotis thysanodes||CSC*,FSC,BLM||A,C|
|Long-legged myotis||Myotis volans||CSC*,FSC,BLM||Not Detected|
|California myotis||Myotis californicus||none||A,C,V|
|Small-footed myotis||Myotis ciliolabrum||FSC,BLM||A,C,V||Silver-haired bat||Lasionycteris noctivagans||none||Not Detected|
|Western pipistrelle||Pipistrellus hesperus||none||A,C,V|
|Big brown bat||Eptesicus fuscus||none||A,C,V|
|Red bat||Lasiurus blossevillii||CSC*,FSS||A,C||Yellow bat||Lasiurus xanthinus||CSC*||Not Detected|
|Hoary bat||Lasiurus cinereus||none||A,C|
|Spotted bat||Euderma maculatum||CSC,FSC,BLM||Not Detected|
|Townsend's big-eared bat||Corynorhinus townsendii||CSC,FSC,FSS,BLM||A,C,V|
|Pallid bat||Antrozous pallidus||CSC,FSS,BLM||A,C,V|
|Molossidae (Free-tailed Bats)|
|Mexican free-tailed bat||Tadarida brasiliensis||none||A,V|
|Pocketed free-tailed bat||Nyctinomops femorosaccus||CSC||A|
|Big free-tailed bat||Nyctinomops macrotis||CSC||A|
|Western mastiff bat||Eumops perotis||CSC,FSC,BLM||A|
1Legal Status categories include California Species of Special Concern (CSC), species proposed to become California Species of Special Concern (CSC*, Betsy Bolster pers. comm.),Federal Species of Special Concern (FSC), Forest Service Sensitive (FSS), and Bureau of Land Management Sensitive (BLM), and Federally Endangered (FE). Source: Calif. Dept. of Fish and Game, Special Animals List, July 2002.
2Detection method: A = Acoustic, C = Mist-net capture, V = Visual observation in roost