Superlative Bats 

12.27.24

By Paul Hormick

We all know that bats are the best. But what of the most outstanding of the best? Let’s take a look at the bats who are the biggest, smallest, loudest, and other bats who hold “world records” in the bat world. 

Smallest

The bumblebee bat (also known as the Kitti’s Hog-nosed Bat) is only about one and one third inches when measured from head to rump, making it not only the smallest bat but the smallest mammal in the world! If one were to land on you, you may not notice, as these brownish red to grey bats with big ears weigh less than 2 grams (about as much as a small coin).

Bumblebee bats are found only among limestone caves close to rivers in forested areas of the Myanmar-Thailand border. At dawn, they leave their roosts to breakfast on flies and small insects for about 18 minutes. They then return to the skies at dusk for a half hour of feeding. They otherwise roost, sleeping or in torpor. Tourism, fertilizer collection, and limestone mining pose the largest threat to the two small areas of habitat of this species.

Largest

The largest bats in the world are the giant golden-crowned flying foxes of the Philippines. They can weigh about three pounds with wingspans that can stretch more than five feet across from wingtip to wingtip. For perspective, that is about as tall as actress Salma Hayek (sans heels).

These flying foxes put those large wings to good use, flying an average of 25 miles per night. And when they aren’t flying, they use their wings as sleeping bags, wrapping their dark brown appendages around them as they roost, rest, and sleep.

Named for the golden fur that adorn their heads, flying foxes live in lowland forests of several Philippine islands. They use their acute sight and smell to find figs and other fruits to eat. This species serves an important ecological function by spreading fig seeds in its droppings.

Fastest Flyers 

In July of 2009, the Guinness Book of World Records, Boston University, Brown University, and other institutions recorded Brazilian free-tailed bats flying at 99.5 miles per hour, which makes this species the fastest bat in the world.

Measuring flight speed is tricky. It’s not as though scientists can set up a marathon among flying creatures with a start and finish line. To clock the bats, scientists performed some tricky piloting of an airplane and tagged the bats with radio transmitters. They explain that the free-tailed bats achieve their great speed because they have aerodynamic bodies and longer wings than most other bats species.

Greater bulldog bats are the heavy metal screamers of the animal kingdom, making ultra-high frequency calls as loud as 140 decibels.

Loudest

The greater bulldog bat hunts for fish in rivers and ponds of South America using echolocation calls that are not particularly loud. But when they want to grab the attention or otherwise communicate with another bulldog bat, they are the heavy metal screamers of the animal kingdom, making ultra-high frequency calls as loud as 140 decibels. These bats and their ears are adapted to this high level of sound, which is as loud as a report from a gun or the din on an aircraft carrier and can cause permanent damage to human ears.

Longest Migration

Unobserved until recently, the straw-colored fruit bat is now known to travel over 1,500 miles across Africa in its seasonal migration. During the rainy season, from October through December, eight million of these large, yellowish bats converge on an evergreen swamp forest in Zambia’s Kasanka National Park to feast on figs, mahogany, and other fruit.

This distinguishes the straw-colored fruit bat as having not only the longest bat migration, but also having the largest migration of any mammal, more than impalas and even elephants! The numbers of these bats can be so great they can fill the night sky. As seed spreaders, this bat is a keystone species for central African ecology, although hunting and deforestation pose threats to these long-distance travelers. 

In summertime, more than 15 million Mexican free-tailed bats make their home in Bracken Cave –  the largest colony of bats in the world.

Largest Bat Colony

In summertime, more than 15 million Mexican free-tailed bats make their home in Bracken Cave just outside of San Antonio, Texas. This is the largest colony of bats in the world. The multitude of bats flying out of the cave each night is so great that they have been compared to the sight of a tornado.

During these summer months, as females give birth and raise their young, this colony also plays a major role for local agriculture. On any given night, these bats consume over 100 tons of corn earworm moths and other crop pests.

In 1992, BCI purchased Bracken Cave and 4.7 acres of surrounding land. Continually expanding upon this initial acquisition and together with the Nature Conservancy, BCI now conserves 3,462 contiguous acres of distinctive and rugged Texas Hill Country around Bracken Cave. Besides conservation efforts for bats, such as monitoring for white-nose syndrome, BCI also sponsors surveys of other wildlife on the preserve, including the black-crested titmouse and the Threatened golden-cheeked warbler. And with the new year upon us, BCI will continue its conservation work at Bracken Cave and throughout the world, wherever bats are found.