Tonto National Monument is home to 14 species of bats. Learn about each of these species below.


Arizona Myotis

Myotis occultus

Length: 1 1/2 - 2"
Weight: 7 grams
Wing-span: 9 - 11"
Diet: Small insects

This medium-sized bat has glossy, generally tawny, pale, tan, reddish brown, or dark brown fur. They have small ears and large feet. This bat is more commonly seen at higher elevations.


Big Brown Bat

Eptesicus fuscus

Length: 2 1/2 - 3"
Weight: 14 - 21 grams
Wing-span: 13 - 16"
Diet: Insects

This large bat has brown glossy- colored fur on their back with lighter colored fur on their belly. They have small round ears. Big brown bats are considered common and range from the extreme northern parts of Canada through the United States, Mexico, Central America, northern South America, and the Caribbean Islands.


Big Free-tailed Bat

Nyctinomops macrotis

Length: 3 - 3 1/2"
Weight: 25 - 30 grams
Wing-span: 17 - 18"
Diet: Moths

This large bat has glossy fur that ranges in color from a pale reddish-brown to a dark brown color with individual hairs white at the base. They have large ears and long, narrow wings. The big free-tailed bat is widespread throughout most of Arizona.


California Myotis

Myotis californicus

Length: 1 1/2 - 2"
Weight: 3 - 5 grams
Wing-span: 9 - 10"
Diet: Small flying insects

This is one of the smallest bats in the United States. They have small dark ears, small feet, and short forearms. In Arizona, the mountain populations are dark-colored and the low elevation populations are pale-colored.


Cave Myotis

Myotis velifer

Length: 1 3/4 - 2 1/4"
Weight: 12 - 15 grams
Wing-span: 11 -13"
Diet: Opportunistic feeders

This bat is light brown to nearly black and has a bare patch on the back between the shoulder blades. They have a long hind foot, stubby-nosed appearance, and their ears only reach to the end of their nose when bent forward.


Mexican Free-tailed Bat

Tadarida brasiliensis

Length: 2 - 21/2"
Weight: 11 - 14 grams
Wing-span: 12 - 14"
Diet: Moths and beetles

This medium-sized bat, also known as the Brazilian free-tailed bat, has reddish to dark brown or gray colored fur. They have broad, black, forward pointing ears and long, narrow wings. They are considered to be the "jets" of the bat world because they are very fast flyers.


Pallid Bat

Antrozous pallidus

Length: 2 1/2 - 3"
Weight: 20 -35 grams
Wing-span: 15 - 16"
Diet: Insects and other arthropods

This bat has yellowish brown to cream color fur on its back and white fur on its belly. They also have large ears. One of the more common species in Arizona, pallid bats probably live in rock crevices above the cliff dwellings.


Pocketed Free-tailed Bat

Nyctinomops femorosaccus

Length: 2 - 3"
Weight: 10 - 14 grams
Wing-span: 13 - 15"
Diet: Moths and other insects

This small to medium sized bat has brown and occasionally reddish fur. The "pocket" that gives this bat its name is formed by a flap of skin between the knee and base of the tail. The rest of the tail is not attached to a membrane.


Southwestern Myotis

Myotis auriculus

Length: 3 - 4"
Weight: 5- 8 grams
Wing- span: 10 -12"
Diet: Moths

This bat is brown in color and has long ears. It is most active one to two hours after sunset at temperatures between 51 and 66 degrees F. In Arizona, this bat is only found in Gila, Maricopa, and Cochise counties. Little is known of the roosting, migratory, or wintering habits of this species.


Townsend's Big-eared Bat

Corynohinus townsendii

Length: 2 - 2 1/2"
Weight: 8 - 14 grams
Wing-span: 12 - 13"
Diet: Moths

These medium-sized bats are pale gray or brown and have very long ears. When their ears are laid back, they extend to the middle of its body. Populations are in decline in most areas. They are sensitive to disturbance and it has been documented that they will abandon roost sites after human interference.


Western Mastiff Bat (Greater Mastiff Bat)

Eumops perotis

Length: 4 1/3 - 6 1/2"
Weight: 56 - 70 grams
Wing-span: 21 - 23"
Diet: Insects

This is the largest bat in the United States. They have short brown fur on their back and paler fur on their belly. They have very large ears that extend out over their nose and long, narrow wings. They remain active year-round; they do not migrate or hibernate.


Western Pipistrelle (Canyon Bat)

Pipistrellus hesperus

Length: 1 1/2 - 1 3/4"
Weight: 3 - 6 grams
Wing-span: 7 - 9"
Diet: Small insects

This is the smallest bat in the United States; they are often mistaken for large moths. Their fur is yellowish to dark gray in color and brown colored on their head and around the base of the ears. The short ears, the muzzle, and membranes are dark brown to black and leathery. Males are generally smaller than females.


Western Small-footed Myotis

Myotis ciliolabrum

Length: 3 - 3 1/2"
Weight: 4 -6 grams
Wing-span:8 - 10"
Diet: Flying insects

This small bat has light brown to yellowish brown fur on its back and slightly lighter colored fur on its belly. It has a flattened cranium, and lacks a distinct forehead. On average, females are larger than males. This bat is often confused with the California Myotis bat.


Yuma Myotis

Myotis yumanensis

Length: 3 - 3 1/2"
Weight: 4 - 6 grams
Wing-span: 9 - 10"
Diet: Soft insects

This small bat has dull brown fur on its back and paler fur on its belly. Their ears are usually light or pale with a pointed tragus. In the summer, this bat is found flying low over the water foraging for food.

Last updated: December 26, 2020

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