Bats are the only mammals that fly. (Flying squirrels glide.) They have furry bodies and membranous wings. Bats have small eyes, but excellent vision. However, they find their food by echolocation, meaning they produce a sound either through their mouth or nose, that bounces back to them, somewhat in the same manner as radar or sonar, enabling them to zoom in on their prey and capture it.
Bats, which usually fly at night, are found in areas with nearby water and plenty of insects. Any place you know?
This excellent page is a superb introduction to bats: Bat Species: Natural History
Bats recorded at Eaton Canyon (Source: Windows into the Wild, Docent Naturalist Training Manual, County of Los Angeles, Department of Parks and Recreation, in cooperation with Nature Center Associates of Los Angeles County, 1982, Mammal Checklist):
Bat Species in the San Gabriel Mountains
- Western pipistrelle (Pipistrellus hesperus), see also here; common, smallest bat in the United States, first to appear in the evening, nicknamed "the canyon bat"
- Big brown bat (Eptesicus fuscus), see also here
- Hoary bat (Lasiurus cinereus); see also here; large (for a bat), frosted coat
Additional bats recorded at Placerita Canyon (from the same source as Eaton Canyon):
- Western long-eared myotis (Myotis evotis), see also here
- California myotis (Myotis californicus), see also here
- Pallid bat (Antrozous pallidus), see also here; a blond bat with big ears
- Western Red Bat (Lasiurus blossevillii)
Bats recorded at San Dimas Experimental Forest
Bats listed as Potentially Vulnerable Species in the Angeles National Forest (Source: Southern California Mountains and Foothills Assessment, United States Department of Agriculture Forest Service, General Technical Report PSW-GTR-172):
- Yuma myotis bat (Myotis yumanensis), see also here; found most commonly below 5,000 feet; associated with rivers and streams; roosts in bridges, buildings, cliff crevices, caves, mines, and trees
- Western small-footed myotis bat (Myotis ciliolabrum), see also here
found at elevations between 3,800 and 7,800 feet; in montane coniferous forests and desert montane habitats; uses a variety of roost types
- Townsend’s big-eared bat (Plecotus townsendii), see also here
roost by exposed, cavity forming rock and/or historic mining areas
- Pallid bat (Antrozous pallidus) found at elevations between 1,100 and 6,600 feet on both coastal and desert sides; roost in rock crevices, tree hollows, mines, caves, and a variety of man-made structures
- Western mastiff bat (Eumops perotis), see also here
a cliff-dwelling species, roost generally under exfoliating rock slabs
Most of the time you won't get close enough to a bat to reveal all these features, but just in case you get lucky here is A Key to the Bats of California
Bats, when they first wake up at dusk, go searching for water, then for their food, insects. They follow certain pathways through the air. To locate bats to watch, first find some water nearer than 1/4 to 1/2 mile away. Then locate some really buggy spot and wait for the sun to set. Eaton Canyon Wash is a very successful spot.
Locating Bats to Watch
- Agricultural areas have all the right stuff, too....abundant water and lots of insects, read Denizens of the darkness
- Tips for Viewing Bats from California Department of Fish and Game, Conservation Education
- Bat Watching 101 from the Northwest, but includes some of our local species
Different bats species eat different kinds of insects. Each species has a unique flight pattern and different sound as well.
Watch for bats in sky zigzaging after the insects. They fly a commute (rather straight) pattern until they locate an insect by echolocation. They turn immediately (zigzag) to go after it.
Since bats can locate very tiny insects using their hearing only, it is extremely unlikely that they will fly into your hair. Instead, because people attract insects, the bats are zooming in after their prey, the insect, for dinner.
Listen to the echolocation clicks of bats and view the sonagrams
What do bats eat?
Bats hibernate and can only be seen from about April 15 through September 15. There are no bats flying at Halloween.
Bats spend much of their time sleeping and resting; this (in)activity is called roosting.
Our local bats typically roost in rock crevices or in trees. Others use man-made structures; but bat houses are rarely successful in attracting bats. Even bird houses fail to attract an occupant 90% of the time; the vacancy rate for bat houses is even higher. Furthermore, bats are loyal to their roosting sites.
- Man-made structures provide important bat roosting habitat
- Bat houses...success is not common
- About bats living in human structures
- Ummm.....bat gardens might look pretty to us, but our local bats eat insects, not flower nectar, except those that live in the LA Zoo
California doesn't have large colonies of bats because there aren't any large karst caves. But bats do inhabit old mines.
- Abandoned mines are bat roosts
- California Underground Realms
- Bracken Cave near San Antonio, home to 40 million bats
- About Diana Simons, bat biologist who gives bat talks and studies the bats in the mountains
- Bats battle maligned mammal moniker
What to do if you find an injured bat
- from Bat Conservation International with local rehabilitators to call
- from California Bat Conservation Fund
Many years ago, in 1984, I (Jane) was on a nature walk with Pat Sullivan, then the director of the Nature Center. We saw a bat flying and determined that it was a hoary bat. A little farther on on our walk, I found one roosting in the sun on a rock, quite visible, but well camouflaged, the blond-brownish frosted coat perfectly matching the rocks on the north-facing cliffside. Since this was daytime and since this bat behavior was so unusual, we were admonished not to touch bats. Pat later collected these bats in a cage using heavy protective gloves. They turned out to have rabies. The point to be made here is to be very careful and not touch the bats especially if they are exhibiting ususual behavior like day flying and roosting in the sunlight.
"Wild animals accounted for nearly 92.0% of reported cases of rabies in 1996. The 6,550 cases reported in 1996...Raccoons continued to be the most frequently reported rabid wildlife species (50.4% of all animal cases during 1996), followed by skunks (23.2%), bats (10.4%), foxes (5.8%), and other wild animals, including rodents and lagomorphs (2.1%)."
Source: Rabies surveillance in the United States during 1996
- Bats and Rabies from Los Angeles County Department of Public Health
- Rabies in Animals in Orange County and Beyond
- Bat-proofing your home from Centers for Disease Control and Prevention
Bats bibliography online and in print
Go to: Field Guide to the San Gabriel Mountains: Natural History: Animals
Copyright © 2001 by Jane Strong and Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
Comments and feedback: Jane Strong | Tom Chester
Updated 18 August 2001