Townsend's big-eared bat
A soft brown bat with enormous curling ears that roosts in the cool lava-tube caves of Lava Beds and hunts moths in the dark.
Townsend's big-eared bat at a glance
Corynorhinus townsendii TOWN-zendz big-eared bat; Corynorhinus townsendii is kor-ee-noh-RY-nus town-ZEN-dee-eye
- Type
- Mammal · bat
- Diet
- Insectivore
- Size
- A small bat, about 4 inches long (10 cm) with a wingspan around 12 to 13 inches (30 to 34 cm), and light enough to mail with a single stamp. Its ears alone are more than an inch long and curl like ram's horns when it rests.
- Lifespan
- Often around 16 years in the wild, and some have lived past 20.
- Conservation
- Least concern globally, but a sensitive species that is easily disturbed; several kinds are protected, and roosts are watched closely.
Eats moths, small flying insects
Townsend's big-eared bat is a night hunter that eats mostly moths. It flies slowly and turns on a dime among the shrubs and trees, using sound to find its food. It sends out squeaks too high for people to hear and listens for the echoes bouncing off insects, a trick called echolocation.
Should you worry?
Bats are not out to hurt you, and they are not 'flying mice' or blind. Never touch a bat, even one on the ground, because a bat that lets you near it may be sick. If you see bats in a cave, stay quiet and keep your distance, because a bat woken during winter can use up the energy it needs to survive. Never go into a closed cave, and follow the ranger's cave rules to help stop a bat disease called white-nose syndrome.
In the cool dark of a lava-tube cave at Lava Beds hangs a small brown bat with a pair of ears so large they look borrowed from a much bigger animal. Each ear is more than an inch long, almost as long as the bat’s whole body, and when the bat rests or gets cold it curls them back over its shoulders like a ram’s coiled horns, then unrolls them to listen. This is Townsend’s big-eared bat, the bat most often found roosting in the caves of the monument.
It hunts at night, and it hunts mostly moths. Flying slowly and turning tightly among the shrubs and trees, it finds its food in total darkness by sending out squeaks too high for people to hear and listening for the echoes bouncing back off an insect, a trick called echolocation. Those giant ears help it catch the faintest echo and the flutter of a moth’s wings. By day the bats gather in the cool caves, and they spook easily. If people disturb a roost, the whole colony may abandon it, which is one reason some caves are closed.
A bat is not out to hurt anyone, and it is not blind and not a flying mouse. The one firm thing to remember is never to touch a bat, even one resting on the ground, because a bat that lets a person come close may be sick. Inside a cave, stay quiet and keep your distance, since a bat woken in winter can burn the energy it needs to last until spring. Follow the ranger’s cave rules, too, which are there to keep a fungus that causes a deadly bat disease called white-nose syndrome from spreading into the caves.
Did you know?
- Its ears are almost as long as its body. When the bat rests or gets cold, it curls those giant ears back over its shoulders like coiled ram's horns, and unrolls them to listen when it wakes.
- It 'sees' with sound in total darkness. The bat squeaks and listens for the echoes to find moths in the black of a lava-tube cave, a skill called echolocation. It can hover and make tight turns most bats cannot.
- It is a picky, careful cave dweller. Townsend's big-eared bats gather in the cool caves of Lava Beds, and they spook easily. If people disturb a roost, the whole colony may abandon it, which is why some caves are closed to visitors.
Common questions
Are bats blind?
No. Bats can see, and this one also uses echolocation, making sounds and listening for echoes, to find moths in total darkness.
Why are its ears so big?
Big ears help it hear the faint echoes and the fluttering of moths. When it is cold or resting, it curls the ears back to save warmth.
Will a bat bite me or get in my hair?
The old story about bats flying into your hair is not true. Bats avoid people. Just never pick one up, because a bat you can catch may be sick.
Why do rangers close some caves?
To protect roosting bats. They are easily disturbed, and people can carry a fungus that causes white-nose syndrome, a disease that kills bats. Following cave rules keeps the bats safe.
When and where might I see one?
At dusk in summer, flying out to hunt near the cave entrances and over the sagebrush at Lava Beds. Inside caves they are quiet and easy to miss, so look, do not disturb.