Order Chiroptera
Ever wonder who enjoys Edgewood at night? Here’s an introduction to the bat species most likely found at Edgewood Park and Natural Preserve: California myotis (Myotis californicus), western red bat (Lasiurus blossevillii), hoary bat (Lasiurus cinereus), western mastiff bat (Eumops parotis), fringe-tailed bat (Myotis thysanodes).
Appearance
The bats found at Edgewood generally have orange/yellow-brown or black/gray fur and have a lighter underbelly than back. Typically, they have a body length of 3-5 inches and a wingspan between 12-16 inches. The western mastiff is the largest with a body from 6-7 inches long and a wingspan of nearly 2 feet.
ID Tips
People seldom see bats up close at Edgewood so it can be difficult to identify the species. Bats are nocturnal, so they are most active at night when the preserve is closed. To determine where bats roost, watch for bat guano – small, black, and pellet-like. Bat guano is found beneath or in roosts.
At Edgewood
Watch for bats at dusk when they forage for insects over grasslands, at the edge of oak woodlands, and over waterways such as streams and creeks. Bats roost in hollowed or dead trees, on the ends of branches, in rock crevices, under loose bark, or in leaf litter. One bat was found resting in a western bluebird box near Edgewood! Beginning in mid-November and lasting through May, bats may be hibernating.
In Edgewood, the main predators of bats include owls, hawks, scrub jays, snakes, and foxes.
See iNaturalist for observations near Edgewood.
About Local Bat Species
These bat species can be found throughout North America in forested or riparian zones. Bats can live for about 15 years in the wild. They reach reproductive maturity at around 1 year and for the most part reproduce, annually. Bats tend to have only one pup, although some may have twins. During the reproductive season, female bats roost in maternity colonies and their young stay with them until they are matured (after 6-8 weeks). After 6-8 weeks, pups will go out on their own. Males generally remain solo, whereas females roost in small colonies. Some species may roost together.
Bats roost in deep crevices that stay warm. Bats climb in using claws on their wings and rest upside down. Bats must “drop” into flight before swooping up, so roosts need at least 10 feet of open drop space below them.
They act as natural pest control. Bats can make both ultrasonic noise and can squeak. They squeak to communicate with each other but use echolocation to gain spacial awareness and find prey. Bats act as natural pest control, and can eat up to their body weight of insects in one night! They hunt and navigate by sending out high-pitched (ultrasonic) sound waves which hit objects or prey and “bounce” back to their ears. If the bat finds an insect, it will swoop, catch it with its tail membrane, and scoop it into its mouth. Bats never leave the air when they eat. Local bat species eat moths, mosquitoes, flies, beetles, dragonflies, flying ants, crickets, other insects, and spiders. A bat can eat its body weight in insects in one night!
Support our Nocturnal Neighbors
Bats are at risk due to human disturbances. Bats may abandon roosts if disturbed, and are losing habitat and food supplies due to human activities such as development and pesticide use.
You can help bats by enlarging their habitat. Build a bat garden or bat box! Bat boxes provide new roosting spaces, while native plants attract insects for hungry bats. Plant native trees, shrubs, and flowers, especially those with light-colored blossoms that are open at night, like toyon (Heteromeles arbutifolia), soap plant (Chlorogalum pomeridianum var. pomeridianum) or common yarrow (Achillea millefolium).
Fun Facts
Did you know that bats are the only flying mammals? Or that bats are more closely related to humans than they are to rats?
Learn More
Instagram: @bat.edu_taylorsgold
Bat Conservation International
Bat Conservation International: Guide to Gardening for Bats
References
National Park Service: Bat Myth-Busters