Habits: During the day the bulldog bat sleeps, washes, and grooms at a roost inside a hollow tree or rock crevice. Large groups of bulldog bats congregate at each roosting place. The sites are easy to locate, since the entire area smells of bat guano (waste matter) even as far as 50 meters away. At dusk the bat leaves the roost to find food, avoiding obstacles by echolocation, which the bat also uses when hunting prey. It hunts for both freshwater and saltwater fish. Sometimes the bulldog bat feeds in daylight near fish-eating birds, but this behavior is unusual. The bulldog bat’s peculiar shaped nose houses its echolocation system.

Food and Hunting: The bulldog bat uses echolocation to find schools of fish. Echolocation means that the animal projects a sound that bounces off the fish or other prey. The bat can determine where the prey is when the sound bounces back. After it has located a school, the bat looks for ripples on the water made by fish near the surface. The bat’s interfemoral membrane (the thin tail skin that stretches between the hind legs) is tucked and folded up between its legs as the bat nears the water.

The bulldog bat skims the water, then trails its claws about one inch beneath the surface and sweeps for fish. The bat catches as many as 30 fish a night. After a sweep, the interfemoral membrane is lowered again so that it can be used for maneuvering as the bat flies off. After catching a fish, the bulldog bat scoops it into its mouth. When the bat lands, it chews up the fish, breaking it into large pieces. The pieces are stored in cheek pouches and chewed again before being swallowed. The bat’s large wings enable it to glide over the water when hunting for fish.

Breeding: Bulldog bats live in mixed sex groups at the roost for most of the year. The adult females group together for birth and during weaning. Males and females do not form pair bonds; that is, they mate with different partners each season. Mating takes place during the winter. One blind and hairless baby is born 16 weeks later. The mother carries it with her for about two weeks, and it begins to fly at 20 days. The young bat reaches adult size within a few weeks of weaning, but it may not reach its full body weight for several years.

Key Facts:
Sizes:
Length: 4-6 in.
Forearm length: 3-4 in.
Wingspan: 11-12 in.
Weight: 2½ oz.

Breeding:
Sexual maturity: 1 year
Mating: Winter
Gestation: About 16 weeks
No. of young: 1

Lifestyle:
Habit: Nocturnal. Roosts in groups
Diet: Small fish and insects
Lifespan: Up to 20 years

Related Species: Only the southern bulldog bat, Noctilio albiventris, which feeds mainly on insects.

Distribution: Forests and mangrove swamps in Central and South America from Mexico to Argentina. Also found in Trinidad and the Antilles.

Conservation: Bat populations are declining worldwide because of habitat and roost loss, hunting, and the effects of pesticides. Many species are now endangered.

Features of the Bulldog Bat:
Head: Tip of the nose projects over nostrils. Thick skin folds above and below fleshy lips. Long, pointed ears.
Body: Head, shoulders, and midback are covered with short, red-brown fur that sheds water. Remainder of body is hairless.
Legs and feet: Legs joined at ankles by tail membrane, which can be folded up and lowered. Large feet well adapted for catching fish.
Flattened toes cut down water resistance. Long sharp claws.

Did You Know:
The bulldog bat is sometimes called the fish eating bat and the Mexican fishing bat.
Two other species of bat prey on fish – the California fishing bat, Pizonyx vivesi, and the false vampire bat, Megaderma lyra, from India. The false vampire bat also eats birds, frogs, and other bats.
Bats make up nearly one quarter of all mammal species found throughout the world.
Besides birds, bats are the only other winged vertebrates that are capable of sustained flight.
Bats roost in large numbers. The largest bat roost in the world is in Carlsbad Caverns in New Mexico, where more than one million Mexican free tailed bats gather during the summer.

To return to animal menu click here