Head to head
Western Mastiff Bat vs Mexican Free-tailed Bat
Western Mastiff Bat
VS Mexican Free-tailed Bat
The western mastiff bat and Mexican free-tailed bat are both fast, high-flying free-tailed bats of the American Southwest, but one is a large, uncommon giant and the other a species that gathers by the million.
| Western Mastiff Bat | Mexican Free-tailed Bat | |
|---|---|---|
| Scientific name | Eumops perotis | Tadarida brasiliensis |
| Size and fame | The largest bat in North America, with a wingspan of around half a metre | Forms the largest gatherings of mammals on Earth, with millions in a single cave |
| Range | Desert, scrub, and rocky canyon country in the southwestern United States and Mexico | The southern United States through Mexico, Central America, and much of South America, and the Caribbean |
| Roost | High crevices on cliffs and rock faces, from which it drops to gain flying speed | Caves, mines, bridges, and buildings, in huge colonies |
| Flight | A fast, high flyer with long, narrow wings | Measured above 160 km/h in straight, powered flight, the fastest level flight recorded |
| Diet | Large flying insects such as moths and beetles | Night-flying insects at high altitude, above all moths, including major crop pests |
| Migration | Not specifically documented | Many populations migrate over 1,000 km between the southwestern United States and central Mexico |
| Conservation status | Least Concern, widespread but uncommon | Least Concern, with a very large population |
Western Mastiff Bat vs Mexican Free-tailed Bat: common questions
Which bat is the largest in North America?
The western mastiff bat, with a wingspan of around half a metre.
Which bat forms the biggest colonies?
The Mexican free-tailed bat, which forms the largest gatherings of mammals on Earth, with millions in a single cave.
Can people hear either bat?
Yes, the western mastiff bat makes echolocation calls pitched low enough that people can sometimes hear them.