California Bats - this page is still being developed
 


Click on the image for a closer view of the bats pictured.

Key to symbols: NHR = Natural Heritage Ranks
G = Global, N = National, S = Sub-National (State)
1=Critically Imperiled, 2=Imperiled, 3=Vulnerable (to extinction), 4=Apparently Secure, 5=Abundant/Secure

Indicated below are only those species that are vulnerable or imperiled in part of their range.

The following bats are listed on this page:

Mexican free-tailed bat

Crevice dweller

These are the most common bats in the southwest US, one of the most numerous mammals in the country.

Merlin Tuttle states, "Given the incredible number of insects eaten, including many pest species, free-tailed bats play a vital role in the checks and balances of nature. Their loss could result in serious environmental consequences.

 


Tadarida brasiliensis
Family, Molossidae; free-tailed bats

Description: Smallest of the free-tailed bats. Dark brown or dark gray above, lighter hairs at base. Ears separated at base. Calcar pointed backward, extending the short interfemoral membrane more than half the length of the tail.

Length: 90-110 mm

Forearm Length: 36-46 mm

Weight: 11-15 grams

Wingspan: 301 cm

Range in California: Statewide, migrating in the winter.

Habitat: Buildings and caves

Diet: Moths (primarily), beetles, leaf hoppers and other small insects.

Reproduction: The males sing to females during courtship. Females (in large nursery colonies) give birth to single pup in June or July.

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Pocketed free-tailed bat

Crevice dweller

 

 

NHR = G4, N3, S2/3


Nyctinomops femorosaccus

Family, Molossidae; free-tailed bats


Description: Dark gray or brown above, lower half of hairs nearly white. Wings long and narrow. Tail free about half bat's length. Ears joined at base. The femoral "pocket" which gives this bat it's common name, is inconspicuous.

Length: 98-118 mm

Forearm Length: 44-51 mm

Weight: 10-14 grams

Wingspan: 345 cm

Range in California: Extreme southern State

Habitat: Rock outcrops in desert

Diet: Moths, ants, wasps, leafhoppers and other insects.

Reproduction: Single pup is born

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Big free-tailed bat

California Species of Special Concern

Crevice dweller

 

 

NHR = G5, N3/4, S2


Nyctinomops macrotis
Family, Molossidae; free-tailed bats

Description: Large, reddish-brown, dark brown or black, with hairs white at base. Tail free for an inch or more, ears joined at base, extending beyond tip of nose when laid forward.

Length: 129-144 mm

Forearm Length: 58-64 mm

Weight: 24-30 grams

Wingspan: 426 cm

Range in California: Southern coastal regions

Habitat: Rocky areas, day roosts in rocky cliffs

Diet: Primarily moths, also feeds on crickets, grasshoppers, ants and other insects.

Reproduction: Single pup is born

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California mastiff bat

California Species of Special Concern

Crevice dweller

When they crawl on all fours, the tail sticks straight up. From the way large ears cover it's head, it gets the nickname "Bonnet Bat."

 

 

NHR = N3


Eumops perotis californicus
Family, Molossidae; free-tailed bats

Description: Largest bat in North America. Body sparsely furred, with dark brown hairs, white at base. Enormous ears, joined at base and protruding over forehead

Length: 140-185 mm

Forearm Length: 72-82 mm

Weight: 65 grams

Wingspan: 550 cm

Range in California: Mid coast through southern State

Habitat: Rocky cliffs and canyons, also buildings

Diet: Primarily moths, also eat crickets and grasshoppers.

Reproduction: Single pup is born

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Big brown bat

Crevice dweller

They have an unusual tolerance for cold and have been seen flying in snowstorms.

Big brown bats are familiar to more people in the United States than any other species of bat because of their tendency to roost in buildings.

Big browns frequently over-winter in buildings as far north as Canada.

Just 150 big brown bats can consume enough cucumber beetles in a summer to protect farmers from 33 million root worm larvae, one of America's most feared pests!


Eptesicus fuscus
Family, Vespertilionidae; evening Bats

Description: Large bat, varying from light brown (in deserts) to dark brown (in forests), usually glossy; belly paler, with hairs dark at base. Wings and interfemoral membrane black, with no fur. Calcar keeled.

Length: 106-127 mm

Forearm Length: 42-51 mm

Weight: 13-21 grams

Wingspan: 325 cm

Range in California: Statewide

Habitat: Roost in man made structures, may move to caves and mines to hibernate during the coldest weather. They also live in hollow trees, crevices and tunnels.

Diet: Beetles (primarily), ants, flies, mosquitos and other insects.

Reproduction: Mating takes place in autumn and winter. In the eastern United States, big browns usually bear twins in early June. In the western United States usually only one baby is born each year.

Photo by Carol Bunyard

Hoary bat

Foliage dweller

A subspecies of this bat is the only bat known to exist in the Hawaiian Islands. The Hawaiian subspecies is on the Federal Threatened and Endangered Species list.

Among the fastest flying bats with a direct swift flight.

Although the most widely distributed bat in US, it is rarely seen.


Lasiurus cinereus
Family, Vespertilionidae; evening bats

Description: Light brown above with tips of fur heavily frosted white, buff throat. Ears short and rounded with black naked rims. Interfemoral membrane well furred above.

Length: 102-152 mm

Forearm Length: 42-59 mm

Weight: 20-35 grams

Wingspan: 400 cm

Range in California: Statewide

Habitat: Hangs from evergreen branches. They are thought to migrate, but the destination is unknown.

Diet: Primarily moths, beetles, and termites

Reproduction: Two babies are born in late spring, early summer.

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(South Western) Yellow bat

Foliage dweller

 

Little is known about this bat.

 

 

NHR = N2


Lasiurus xanthinus
Family, Vespertilionidae; evening bats

Description: Large, yellowish buff. Basal half of interfemoral membrane furred above. Ears are large, longer than wide, pointed, and partially furred outside, reaching end of nose when laid forward.

Length: 109-126 mm

Forearm Length: 45-48 mm

Weight: 10-23 grams

Wingspan: 335-355 cm

Range in California: Small portion of southern State.

Habitat: Leafy vegetation. They are often found in Spanish moss. They do not migrate.

Diet: Insects

Reproduction: One to four pups are born, May through June.

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Photo by Dick Wilkens

Spotted bat

California Species of Special Concern

Crevice dweller

Rare

It is also referred to as the "Death's Head Bat" because of it's striking coloration.

 

 

NHR = N3/4, S2/3


Euderma maculatum
Family, Vespertilionidae; evening bats

Description: Black above with three large white spots on back (one on each shoulder and at base of tail); white below. Huge ears, almost 51 mm long.

Length: 107-115 mm

Forearm Length: 44-55 mm

Weight: 15-20 grams

Wingspan: 365 cm

Range in California: Southern State

Habitat: Primarily in crevices in rocky cliffs and canyons. Ponderosa pine forests.

Diet: Moths (almost entirely)

Reproduction: Single pup born in May or June.

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Townsend's big-eared bat

California Species of Special Concern - not considered by all to be a California species

It is possible that these bats will receive Federal ranking as Threatened and Endangered

Crevice dweller

When at rest, the ears are folded on the back like ram's horns. When disturbed, the ears unfold and move in circles like antennae.

NHR = S3/4

 



Corynorhinus townsendii
Family, Vespertilionidae; evening bats

Description: Pale gray or brown above; buff under parts. Wings and interfemoral membrane naked. Enormous ears, extending to middle of body when laid back; two large glandular lumps on nose..

Length: 89-110 mm

Forearm Length: 39-48 mm

Weight: 7-12 grams

Wingspan: 293 cm

Range in California: Statewide

Habitat: Caves or buildings, scrub deserts, pine and pinion forests. Even in the coldest weather, these bats often move between caves.

Diet: Moths (almost entirely)

Reproduction: Single pup is born in May or June.

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Allen's big-eared bat

California Species of Special Concern

Crevice dweller

 

 

NHR = G3, S1


Idionycteris phyllotis
Family, Vespertilionidae; evening bats

Description: Tawny above with hairs dark brown at base; under parts slightly lighter. No fur on wings or membranes. Long tragus (16 mm); white patches behind enormous ears, with two flaps projecting forward from base of ear (the only big-eared bat with such flaps).

Length: 94-118 mm

Forearm Length: 42-49 mm

Weight: 8-16 grams

Wingspan: 310-350 cm

Range in California: Far southeast of State

Habitat: Caves and mines in forested areas

Diet: Insects

Reproduction: Single pup is born

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photo by Brian Murphy

Pallid bat

Crevice dweller

Feeds primarily on the ground, noted for consuming scorpions.

A skunk-like order given off by glands on the muzzle is most pronounced when the bat is disturbed.

In captivity pallid bats have been observed capturing and consuming lizards.

 

 

NHR = S3


Antrozous pallidus
Family, Vespertilionidae; evening bats

Description: Large, creamy to beige above, nearly white below. Big ears, long and separated at base, large eyes and broad muzzle. Wings and interfemoral membrane essentially naked.

Length: 107-130 mm

Forearm Length: 45-60 mm

Weight: 17-35 grams

Wingspan: 353 cm

Range in California: Statewide

Habitat: Daytime roosts in buildings and crevices, less often in caves and other shelters.

Diet: Since it feeds primarily on the ground, they are sometimes caught in mousetraps. Food consists primarily of large flightless insects, usually those that are a problem to people.

Reproduction: Mate in fall, can have 1-3 pups, usually bearing twins in June. Female roost mates have been observed helping each other through labor and will baby sit for each other as well.

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Silver-haired bat

Crevice and foliage dweller

Silver-haired bats have a well-developed homing instinct; one bat traveled 107 miles to it's home roost.

Silver-haired bats are among the slowest of flyers.


Lasionycteris noctivagans
Family, Vespertilionidae; evening bats

Description: Medium-sized, silky black, with silvery tipped hairs on back giving a frosted appearance. Interfemoral membrane lightly furred above. Short, rounded, naked ears.

Length: 92-110 mm

Forearm Length: 37-44 mm

Weight: 6-15 grams

Wingspan: 289 cm

Range in California: Northern and central State

Habitat: In summer, woods in protected spots (under bark; in dead trees, woodpecker holes, bird nests). In winter hibernates in trees, crevices and buildings.

Diet: Favors moths and flies. They forage later in the evening than other bats and their erratic flight is one of the slowest.

Reproduction: Females usually bear one or two young in June or July.

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Western pipistrelle

Crevice dweller

Smallest bat in the United States.


Pipistrellus hesperus
Family, Vespertilionidae; evening bats

Description: Light yellow or grayish to reddish-brown above; belly whitish. Wings, interfemoral membrane, ears, nose and feet blackish. Calcar keeled. One tiny premolar behind canine.

Length: 60-86 mm

Forearm Length: 27-33 m

Weight: 3-6 grams

Wingspan: 190 cm

Range in California: Statewide except far north

Habitat: Caves, deserts, rocky areas, scrub, buildings.

Diet: Insects - they are usually the first bat to appear in the evening, often before dark, sometimes seen in broad daylight. They drink while skimming a pond or stream.

Reproduction: Twins are born from late May to early July.

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photo by Brian Murphy

Photo by Carol Bunyard

(Western) Red bat

California Species of Special Concern

Foliage dweller

Red bats are almost fully furred and can respond to cold temperature by increasing their metabolism. Predators include many types of birds.

They live solitary lives, coming together only to mate and migrate.

Red bats almost never enter buildings and pose extremely little threat to anyone who simply leaves them alone. They are valuable allies in reducing moths that are costly pests.


Lasiurus borealis
Family, Vespertilionidae; evening bats

Description: Males red or orange-red, females duller, brick or chestnut; both sexes frosted white on back and breast, with whitish patch on each shoulder. Ears small and rounded, tragus small. Interfemoral membrane furred above.

Length: 95-126 mm

Forearm Length: 35-45 mm

Weight: 9-15 grams

Wingspan: 312 cm

Range in California: Mid-State extending southward. They migrate to the southern part of their range in winter, or may hibernate, emerging on warm days to feed.

Habitat: In dense foliage, usually in trees, hanging by one foot, giving them the appearance of a dead leaf.

Diet: Red bats commonly feed beneath street lights, on moths, crickets, flies, mosquitos, true bugs, beetles, cicadas and other insects.

Reproduction: They mate in flight during August and September, the sperm is stored over winter, and females give birth to 1-4 babies during the late spring or early fall. They are the only bat with 4 nipples.

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(Western) Small-footed myotis

California Species of Special Concern

Crevice dweller

 

 



Myotis ciliolabrum

Family, Vespertilionidae; evening bats
Myotis (mouse-eared)

Description: Glossy fur, light tan to golden brown above; buff to nearly white below. Wings and interfemoral membrane are dark brown, keeled calcar, black ears and a black mask. It's hind foot, for which it is named, is slightly smaller than that of other members of it's genus.

Length: 71-82 mm

Forearm Length: 30-36 mm

Weight: 4-9 grams

Wingspan: 242 cm

Range in California: Statewide except coastal regions

Habitat: Little is known, have been found beneath rock slabs, in crevices, and in buildings. It hibernates in small numbers in caves, often wedged into crevices, sometimes under rocks on the cave floor.

Diet: Moths, beetles

Reproduction: Single pup is born

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(Western) Long-eared myotis

California Species of Special Concern

Crevice and foliage dweller

 

 

 

 

 



Myotis evotis

Family, Vespertilionidae; evening bats
Myotis (mouse-eared)

Description: Long glossy fur, light brown to brown. Ears dark, usually black, and longer than other in other myotis - 22-25 mm extending beyond nose when laid forward.

Length: 75-97 mm

Forearm Length: 35-41 mm

Weight: 4-9 grams

Wingspan: 275 cm

Range in California: Most of State except arid southeast portion.

Habitat: Coniferous forests of high mountains; sometimes in buildings, sometimes roosting in tree bark; night roosts in caves.

Diet: Small moths, flies, beetles and other insects.

Reproduction: Single pup is born

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photo by Brian Murphy

California myotis

Crevice and foliage dweller

An ability to veer suddenly sideways, up, or down makes their flight conspicuously erratic.

 



Myotis californicus

Family, Vespertilionidae; evening bats
Myotis (mouse-eared)

Description: Dull fur, light to dark brown with yellowish or orange cast above; paler below. Ears, wings, and interfemoral membrane dark, tiny foot, keeled calcar.

Length: 74-85 mm

Forearm Length: 29-36 mm

Weight: 3-5 grams

Wingspan: 220 cm

Range in California: Statewide

Habitat: Desert to semi-desert areas, especially in rocky canyons. By day roost in buildings, under bridges, under bark, in hollow trees; by night, in buildings. In winter some hibernate in mines, some remain active.

Diet: Small flies and moths

Reproduction: Single pup is born

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Long-legged myotis

California Species of Special Concern

Crevice and foliage dweller


Myotis volans

Family, Vespertilionidae; evening bats
Myotis (mouse-eared)

Description: Large, tawny or reddish to nearly black above, grayish to pale buff below. Calcar with well-developed keel. Short ears. Underarm and interfemoral membrane furred to elbow and knee.

Length: 87-103 mm

Forearm Length: 35-42 mm

Weight: 5-9 grams

Wingspan: 267 cm

Range in California: Statewide

Habitat: In summer, trees, crevices, and buildings, especially in forested areas. Winter habits unknown.

Diet: Small moths and other small insects

Reproduction: Single pup is born

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Fringed myotis

California Species of Special Concern

Crevice dweller

 

 

NHR = S4

 

The subspecies - myotis thysanodes vespertinus
(pacific fringe-tailed bat) has a
NHR = N2
This is a fairly new subspeciesidentified in 1988


Myotis thysanodes

Family, Vespertilionidae; evening bats
Myotis (mouse-eared)

Description: Reddish-brown or brown above; slightly lighter below. Unique in having a "fringe of hairs on back of interfemoral membrane".

Length: 80-95 mm

Forearm Length: 39-46 mm

Weight: 6-11

Wingspan: 285 cm

Range in California: Central State from north to south.

Habitat: Roost in caves, mines, buildings, and other protected locations; oak, pinions, and juniper forests; desert scrub. Winter habits are unknown.

Diet: Moths, crickets and daddy-longlegs.

Reproduction: Single pup is born

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Cave myotis

California Species of Special Concern

Is not considered by all to be a California species

Crevice dweller

 

 

NHR = N4, S1

 

The subspecies - myotis velifer brevis (southwestern cave myotis) has a
NHR = T4, N3/4, S3/4


Myotis velifer

Family, Vespertilionidae; evening bats
Myotis (mouse-eared)

Description: Large, light brown to black. Calcar not keeled. Ears reach tip of nose when extended forward.

Length: 90-115 mm

Forearm Length: 37-47 mm

Weight: 15 grams

Wingspan: 296 cm

Range in California: Extreme southeast State

Habitat: Arid southwest; in summer roosts in caves and mines, sometimes buildings; in winter, caves. They migrate between summer and winter quarters.

Diet: Small moths, weevils, small beetles

Reproduction: Single pup is born

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Yuma myotis

California Species of Special Concern

Crevice dweller


Myotis yumanensis

Family, Vespertilionidae; evening bats
Myotis (mouse-eared)

Description: Short, dull fur. Variable shades of brown above, lighter below, with throat sometimes whitish. Calcar not keeled.

Length: 84-99 mm

Forearm Length: 32-38 mm

Weight: 4-7 grams

Wingspan: 225 cm

Range in California: Statewide

Habitat: Always near ponds, streams or lakes. Roosts under siding or shingles by day, night roosts often in buildings. Maternity colonies in caves, mines, buildings or bridges.

Diet: Midges, moths, termites and other small insects. Closely associated with water, they feed by flying very low over the surface.

Reproduction: Single pup is born

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Little brown bat

Crevice dweller

Their life span may be more than 30 years in the wild.

A colony of 500 can easily consume more than a quarter million insects in an hour.

 

 

 


Myotis lucifugus
Family, Vespertilionidae; evening bats
Myotis (mouse-eared)

Description: Various shades of glossy brown above, buff below. Ears, 14-16 mm; tragus short and rounded. Calcar without keel.

Length: 79-93 mm

Forearm Length: 34-42 mm

Weight: 7-9 grams

Wingspan: 239 cm

Range in California: Statewide

Habitat: Inhabits buildings, females form colonies of hundreds or thousands, usually close to a lake or stream. They prefer to forage over water but will forage among trees.

Diet: Gnats, crane flies, beetles, wasps and moths. Insects are usually captured with a wing tip. They are very efficient hunters, a single bat can capture and eat up to 500 mosquitos in an hour.

Reproduction: Mating occurs in autumn, sperm is stored until spring, and one baby is born in May through early July. The mother keeps the baby beneath a wing when at rest.

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California leaf-nosed bat

California Species of Special Concern

Crevice dweller

 

The only leaf-nosed bat that is a permanent resident of the United States

Their populations have recently declined because of human disturbance and are being considered as candidates for Federal Threatened and Endangered ranking.

The California leaf-nosed bat is the only insectivorous bat in North America to supplement it's diet with cactus fruit.

 

NHR = S2/3

 


Macrotus californicus
Family, Phyllostomidae; leaf nosed bats

Description: Grayish to dark brown above with fur nearly white at base; paler below. Large ears, erect triangular flap on nose.

Roosts: In small colonies of up to 100, not touching each other.

Length: 84-110 mm

Forearm Length: 45-58 mm

Weight: 8-20 grams

Wingspan: 340 mm

Range in California: Southern State

Habitat: Desert scrub, abandoned mine tunnels and caves by day. They do not hibernate or migrate but will die if their body temperature falls below 79 F.

Diet: Insects, some flightless are plucked from the ground or from low foliage. Cactus fruit.

Reproduction: Mating takes place in the fall. A single pup or twins are born from May to July.

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Mexican long-tongued bat

California Species of Special Concern

They are being considered a candidate for Federal Threatened and Endangered listing.

This species of bat is rare and they are easily disturbed.

 

NHR = S1


Choeronycteris mexicana
Family, Phyllostomidae; leaf nosed bats

Description: Gray or brownish above; paler below, large eyes. Long slender nose has an erect arrowhead-shape flap of skin. Tiny tail extends less than halfway to end of interfemoral membrane.

Length: 55-78 mm

Forearm Length: 43-45 mm

Weight: 10-25 grams

Wingspan: 345 mm

Range in California: Extreme southwest State

Habitat: Canyons in mountain ranges rising from the desert. By day they roost in caves and mines, sometimes in buildings, where they tend to roost near the entrance. These bats migrate.

Diet: The long tongue and lack of lower incisors make it easy for these bats to lap up flower nectar and fruit juices. They also eat insects, pollen, and the fruit of the Agave and other night-blooming cacti.

Reproduction: Single pup is born

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Literature Cited:

The Biology of Bats - G. Neuweiler, 2000
Bats of the United States
- M. J. Harvey, J. S. Altenbach, T. L. Best, 1999
America's Neighborhood Bats - M. Tuttle, 1997
Walker's Bats of the World - R. M. Nowak, 1994
Bats of the World
- G. L. Graham, 1994

 

 
 
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