Pallid Bat as the California State Bat
Background information for a 2017 Senate Bill to make the pallid bat the California State Bat
Likely Sponsor to introduce into the legislature: State Senator Bill Dodd
Advocate: Dave Johnston, bat biologist
Bats help agriculture in California. Bats provide an estimated 3.7 billion dollars’ worth of pest control management for U.S. Agriculture (Boyes et al. 2011), much of which is located in California. The University of California Farm Advisory has determined that bats eat the codling moth, a serious pest of walnut crops, and University of California (UC) Davis researchers are working with walnut growers to help determine the economic value of the bats’ pest control management for California walnut growers.
Bats help reduce insects and arthropods that contribute to health risks. Bats eat many other pest species including those that contribute to health risks such as flies, wasps, and mosquitoes. Pallid bats eat a variety of insects and arthropods including grasshoppers, moths, beetles, spiders, scorpions, and centipedes. Bats that are nursing their young eat from about two thirds to all of their weight in insects and arthropods every night.
Pallid bat description. Pallid bats are relatively large bats compared with other bats in California, are light colored, and have fairly long ears. There are two subspecies in California, the large one being the Pacific pallid bat (Antrozous pallidus pacificus), found almost exclusively in California, and the smaller one being the desert pallid bat (Antrozous pallidus pallidus), found throughout much of the U.S. southwest desert.
Pallid bat ecology. Pallid bats are crevice roosting bats; that is, they spend their daytime in the crevices of rocks, cavities of trees and behind bark, and occasionally in barns, bridges, and other anthropomorphic structures. They roost as individuals, small clusters, or rarely as larger colonies up to about 200. They congregate at night roosts in rock grottos, barns, bridges, and sometimes on porches as they eat, digest their prey, and socialize. Overwintering roosts have relatively cool, stable temperatures and in many areas of northern California are located in protected structures beneath the forest canopy or on the ground, out of direct sunlight. In desert regions of Southern California this species has been observed hibernating alone or in small groups in rock fissures, mines, caves and buildings. Females typically have 1 or 2 young per year and are expected to live for 10 to 15 or more years in the wild. Pallid bats are a social species and exhibit an extensive repertoire of social communication calls, many of which are audible to humans. Pallid bats forage primarily in open grasslands, oak savannah, desert washes, open desert, vineyards, orchards, open pine forests, and on dirt roads such as logging roads. These bats generally use passive listening to detect prey and then they glean their prey from the ground or vegetation surfaces. However, this species also detects aerial prey through echolocating and it captures prey while flying. Their diet composition and foraging style vary within and among different populations.
Naming the pallid bat as the official state bat of California will promote an appreciation of the benefits of bats, more education about their ecological roles, and more conservation for bats in this state.
Boyles, J.G., P.M. Cryan, G.F. McCracken, and T.H. Kunz. 2011. Economic Importance of bats to Agriculture. Science 332: 41—42.