Mammals · Chiroptera · Molossidae

Mexican Free-tailed Bat

Tadarida brasiliensis

Least Concern

The species is abundant and widely distributed; it faces no significant short-term risk. See full glossary

It can reach horizontal flight speeds of up to 160 km/h, the fastest level flight documented in any mammal. Its colonies can number 10 to 20 million.

Weight

7 g – 15 g

Size

8 cm – 10 cm

Lifespan

8 years

Diet

Insectivore

Feeds mainly on insects and other invertebrates.

Activity

Nocturnal

Active mainly at night.

Social structure

Colony

Lives in large concentrations, often for breeding reasons.

Sighting difficulty

Easy

DesertGrasslandInsectivore Nocturnal Colonial Desert Grassland Mammal

5countries 17parks2same family

Fun facts

It can fly at up to 160 km/h, the fastest level flight documented in any mammal.
Its colonies can reach 20 million, as at Bracken Cave in Texas.
It leaves its pups in communal crèches while the mother forages.

Life cycle & biology

Skeleton type: Vertebrate - internal bony skeleton (mammal)
Habitat & environment: A wide range of habitats in North, Central and South America, forming some of the largest mammal colonies in the world in caves and under bridges
Birth weight: 2.8 grams
Size at birth: The young naked at birth, left in communal crèches while its mother forages
Sexual maturity: Female: 9 months | Male: 18 months
Gestation / incubation: 78 days (with delayed implantation in some populations)
Litter / clutch size: 1 young per litter

Sources consulted: AnAge (genomics.senescence.info); Natural History Museum of Utah fact sheet; Nevada Dept. of Wildlife; A-Z Animals; Animal Diversity Web; Bat Conservation International; Wikipedia (Mexican free-tailed bat)

Where to find it

See its range on the interactive map

Best time: From May to September in Texas and northern Mexico, at dusk, when millions of bats stream out in a column from caves and from city bridges.