Bats are essential members of many types of ecosystems, and by fulfilling their ecological roles they promote biodiversity and support ecosystem health. They play an important role in pest
control, pollinating plants, and dispersing seeds. It is estimated that by eating insects, bats save U.S. agriculture billions of dollars per year in pest control. Over 300 fruit species
alone depend on bats for pollination!
Bat populations have been declining in North America for decades. Human activities, such as urbanization and conversion of land to agriculture, have reduced roost sites and foraging habitat
for bats. Pesticide use also affects bat populations by killing the insects upon which many bats feed, and human disturbance during hibernation have proven detrimental for
bat populations. In San Diego County, 23 species of bats have been recorded, and eight of those are California Species of Special Concern. The Townsend's big-eared bat (Corynorhinus
townsendii) and pallid bat (Antrozous pallidus) were once widespread throughout San Diego County, but both are now listed as California Species of Special
Concern.
