What Is the Biggest Bat in the World? Giant Flying Foxes

The giant golden-crowned flying fox: biggest by wingspan

The giant golden-crowned flying fox is found only in the Philippines. It has the longest forearm of any bat ever measured, up to about 21.5 cm (8.5 in), which supports a wingspan of about 1.5–1.7 m (4.9–5.6 ft). It weighs up to about 1.4 kg (3.1 lb).

It gets its name from a patch of golden fur that runs from between its eyes over the top of its head to the nape of its neck. The rest of the coat is a mix of black, maroon and reddish brown.

This giant feeds mainly on figs and some leaves, foraging at night in forests and roosting by day in tall trees, sometimes in colonies of thousands shared with large flying foxes. Sadly, it is listed as Endangered by the IUCN because of deforestation and hunting for meat. One subspecies, the Panay golden-crowned flying fox, is already extinct.

The large flying fox: a close second

The large flying fox (Pteropus vampyrus) is the other bat most often named as the world’s biggest. Its wings span up to about 1.5 m (4 ft 11 in), and it weighs 0.6–1.1 kg (1.3–2.4 lb), with a head and body 27–32 cm (11–13 in) long.

It is much more widespread than the golden-crowned flying fox, ranging across Southeast Asia from southern Myanmar, Thailand and Vietnam to the Philippines and Indonesia. Despite the scary scientific name, it eats only fruit, nectar and flowers. It too is listed as Endangered, mainly because of hunting and habitat loss.

What is the heaviest bat?

The heaviest bats are all flying foxes, but the exact ranking depends on which records you use. Published maximum weights include:

These are maximum records for exceptionally large individuals. Most adults of these species weigh less, and weights change with season and how recently a bat has eaten. Even the heaviest bat weighs well under 2 kg (4.4 lb), because flying animals must stay light.

Why are flying foxes so big?

Flying foxes belong to the Old World fruit bat family (Pteropodidae), also called megabats. Unlike most small bats, they do not hunt insects by echolocation. Instead they use sight and smell to find fruit and flowers, which allows a larger body. Big wings also let them commute tens of kilometers between roosts and feeding trees each night. Read more about their diet in What do fruit bats eat?.

Not all megabats are giants, though. Nearly a third of species weigh less than 50 g (1.8 oz), and some small blossom bats weigh only around 15–20 g.

The myth of human-sized bats

Photos claiming to show “human-sized bats” spread widely online, notably a picture from the Philippines that went viral in 2020. These images show real flying foxes, usually golden-crowned or large flying foxes, hanging upside down with their long wings folded. The trick is forced perspective: the bat is much closer to the camera than the background, so it looks enormous.

In reality, the head and body of even the largest bat is only about 30 cm (1 ft) long, roughly the length of a school ruler, and the bat weighs about as much as a bag of sugar. Hanging with its wings folded, it might look as long as a person’s arm, but nowhere near the size of a person.

The biggest bats in North America and Europe

Bats in the Americas and Europe are much smaller than the Asian flying foxes:

• Americas: the spectral bat (Vampyrum spectrum) of Central and South America is the largest bat in the Americas, with a wingspan of up to about 1 m (3.3 ft). It is also a meat-eater, catching birds, rodents and other bats. In the United States, the western mastiff bat is usually named the largest, with a wingspan of up to about 56 cm (22 in).
• Europe: the greater noctule (Nyctalus lasiopterus) is the largest insect-eating bat, with a wingspan of about 41–46 cm (16–18 in). In the EU, Cyprus is also home to the Egyptian fruit bat, Europe’s only fruit bat, with wings of around 60 cm (2 ft).

For an American bat of a very different kind, see the common vampire bat, which weighs only 15–50 g (0.5–1.8 oz).

What is the smallest bat?

At the other extreme is Kitti’s hog-nosed bat (Craseonycteris thonglongyai), also called the bumblebee bat. It lives in limestone caves in western Thailand and southeastern Myanmar. Its body is only about 29–33 mm (1.1–1.3 in) long and it weighs around 2 g (0.07 oz), less than a penny. It is a contender for the smallest mammal in the world by body length, while the Etruscan shrew is usually considered the smallest by weight.

That means the heaviest flying foxes weigh roughly 700–800 times as much as the smallest bat. To find out where all these bats live, see Where do bats live?.