Discover the Hammer-Headed Bat: The Giant-Headed, Fruit-Eating Creature

The largest species of bat found in continental Africa is the hammer-headed bat (Hypsignathus monstrosus). The males and females of this bat species exhibit significant physical differences, making it the most sexually dimorphic species globally. Continue reading to learn more about these peculiar fruit bats!

Hammer-Headed Bat Appearance

Hammer-headed bats have huge eyes, dark brown wing membranes, and wooly, slate-brown fur with a paler mantle on both the male and female species. On the other hand, males grow to be almost twice as huge as females. Males typically weigh 420 g (15 oz), whereas females only weigh 234 g (8.3 oz). Additionally, the wingspans of males are bigger, reaching lengths of around 1 m (3.3 ft).

The enormous hammer-shaped head that gives the species its name, together with an expanded nose and thick lips, are also unique to males. However, females resemble other species of fruit bats in having smaller, more fox-like features. However, males do not develop their characteristic facial traits until they are approximately 12 months old.

Why Do The Males Look So Different?

The males’ peculiar noggin are associated with their unique adaptations for vocalization production and amplification, which are crucial for luring females. As the diagram above illustrates, the male’s face contains a sizable resonating chamber. In addition, the male has an expanded larynx that is almost three times larger than the female’s; in fact, it is so big that it pushes aside the heart and lungs among other organs!

Where Hammer-Headed Bats Live

Hammer-headed bats inhabit a wide range of West and Central African forests. Found below 5,900 feet (1,800 meters) above sea level, this species is lowland. It is present in mosaics of forest and grassland, mangroves, riverine forests, swamps, and rainforests.

Hammer-headed bats are nocturnal animals, just like many other bat species. They forage for food at night and roost 20–30 m (66–98 ft) high in the forest canopy during the day. Up to 25 people can be found in a roost, while fewer than five are more typical. Males and females as well as adults and juveniles coexist in the same roosts.

Hammer-Headed Bat Diet

Similar to other fruit bats, hammer-headed bats are frugivores. Their main food source is figs, but they also consume bananas, guavas, mangoes, and soursops. Fruit can be collected and carried to a nearby tree to be eaten, or it can be consumed right where it is discovered. They consume food by chewing on the fruit, swishing off the pulp and juice. But they do unintentionally consume seeds and disseminate them through their guano, which could make them significant seed dispersers.

It’s interesting to note that males and females forage differently. Using a trap-line approach, females forage along well-established paths with consistent, though occasionally subpar, food sources. Males, on the other hand, seek out high-quality food sources and may travel up to 10 km (6.2 mi) to get the greatest fruit resources.

Hammer-Headed Bat Reproduction

Hammer-headed bats spawn up to twice a year during the local dry seasons in the wild. The lek mating system is predominant in most regions, although the harem mating system is more common in other parts of West Africa.

Every night, groups of males congregate along river or stream beds to engage in lekking, for the majority of them. The males defend their territory inside the arena by separating themselves at intervals of 10 meters (33 feet) and try to draw in pursuing females by loudly honking and flailing their wings. Then, the females select their partners from the lineup.

Although twins are conceivable, females typically give birth to a single pup at a time. At birth, the puppies weigh 40 g (1.4 oz), and their moms are their only caregivers. While males might take up to 18 months to reach sexual maturity, females can reach it as early as six months.

Hammer-Headed Bat Predators

Large birds of prey are the main wild predators of hammer-headed hawks. In certain places, people hunt them for bushmeat as well. The primary defense mechanism used by hammer-headed bats against predators is camouflage; they blend into the trees throughout the day as they sleep.

Hammer-Headed Bat Conservation

The hammer-headed bat is now classified as a species of Least Concern on the IUCN Red List because of its broad distribution, estimated big population that does not seem to be declining quickly, and presence in at least some protected areas. However, accurate estimates of their real population are nonexistent. It is thought that habitat loss, hunting, and persecution by humans as a pest species are the main risks to the species. In captivity, hammer-headed bats are also quite uncommon. There’s still a lot to discover about the largest and most distinctive-looking fruit bat in Africa!