Hammer-headed Fruit Bat

The hammer-headed bat (Hypsignathus monstrosus), widely distributed in equatorial Africa, is one of three species of African fruit bat thought to be asymptomatically infected with the Ebola virus; though scientists do not know if the species is an incidental host or a reservoir of Ebolavirus.

The little-collared fruit bat (Myonycteris torquata) and the Egyptian fruit bat (Rousettus aegyptiacus) are the other two species. The species is locally common and is typically found in lowland tropical moist forests, riverine forests, swamp forests, mangroves and palm forests, where it roosts in trees. Although colonies up to 25 bats have been observed, the average hammer-headed fruit bat roost is fewer than five bats.

The hammer-headed bat, with wingspans up to 38 inches (97 cm), is Africa’s largest bat. Strong sexual dimorphism is observed in the species, as males are significantly larger than females. Males have a large head with enlarged rostrum, larynx and lips that allows for the production of loud honking calls; the appearance of females is similar to most other fruit bats. The species has a “lek” mating system whereby a few hundred males gather into groups (leks) to attract female mates.

Although hammer-headed bats are frugivorous, they are generally not considered to be effective seed distributors as they tend to consume their food in the same area where they find it. Figs are often a major component of their diet, and they also are known to forage on bananas, guavas, mangos and other cultivated crops. The hammer-headed bat is considered a crop pest due to its diet of fruit.

The IUCN Red List of Threatened Species lists the hammer-headed bat as “Least Concern” due to the species’ widespread distribution and presumed limited threats to its habitat. However, in some parts of its range, hammer-headed fruit bats are threatened by deforestation, particularly the loss of riverine forests, and it is hunted as bushmeat. As it is found in Tai National Park (Côte d’Ivoire), and with its range throughout equatorial Africa, it is likely found in other protected areas and is thought to be relatively secure.

However, in light of ongoing deforestation and habitat changes due to climate change, persecution, and hunting, continued monitoring is needed to ensure that the hammer-headed fruit bat remains one of Africa’s most iconic and ecologically important species.