- Bats are one of the most diverse orders of mammals and represent an important component of ecological balance. They may make up a large portion of the mammal diversity — including in countries like Rwanda where much of the natural forest and savannah habitats have been lost, changed or degraded.
- Researchers recently discovered two rare bat species in Rwanda’s Nyungwe National Park, and the IUCN lists 54 species of bats as occurring in the country.
- Research shows that killing bats to control zoonotic diseases can make things worse.
- Several studies show that bats are important predators of insects and are, therefore, a natural asset for agrarian productivity, suppressing pest populations.
KIGALI, Rwanda ― Following the recent rediscovery of the critically endangered Hill’s horseshoe bat (Rhinolophus hilli) at Nyungwe National Park in southwestern Rwanda, researchers are calling for actions and policies aimed at their conservation.
Scientists say that this is the first sighting and documentation of the horseshoe bat Rhinolophus webalaiin the park and Rwanda’s first observation of the Damara woolly bat (Kerivoula argentata) since it was last observed in 1981.
According to Paul Webala, a senior lecturer in wildlife biology at the department of forestry and wildlife management at Kenya’s Maasai Mara University, scientists consider bats the second-most diverse group of mammals after rodents. In countries like Rwanda, he says, where most of the natural forests and savannah habitats have been lost, altered or degraded, bats may comprise “at least 40% of the overall mammal diversity.”
According to a 2022 study that Webala co-authored, insectivorous bats in Rwanda provide critical ecosystem services and also act as pest controllers in agricultural areas.
Health concerns, and habitat loss
“In Rwanda, one of the [bat] species of concern, although not threatened according to the IUCN Red List, is the Egyptian fruit bat [Rousettus aegyptiacus] because it has been identified by health officials as a natural reservoir host for the Marburg virus disease,” Webala says.
In February this year, Rwandan health officials decided to construct a wall in a mining site located in Nyamirambo a suburb of the capital city Kigali separating a working area from the bats’ habitat.
“This barrier is intended to reduce direct contact between humans and bats, significantly lowering the risk of transmission,” said the statement issued then by the Ministry of Health in Kigali.
However, a team of Rwandan and international conservation researchers is yet to find the virus in Rousettus to directly link the bats to the index case.
This is because bats are too often vilified and grouped by policy makers into a single biological unit, yet in the view of conservation scientists, the reality is these mammals are an extremely diverse group of over 1482 species, second in diversity only to rodents within the Mammalia.
Webala is currently working with a team of conservation researchers from the government’s Rwanda Development Board (RDB) to map out roost sites for the Egyptian fruit bats to ensure their protection and to monitor them for disease surveillance.
“Protecting the [bat] caves [in Rwanda] is crucial, as eliminating all bats would be counterproductive for numerous reasons,” Webala tells Mongabay.
According to him, the public health problems posed by bats are relatively insignificant but typically result in exaggerated and inappropriate responses.
In addition, Webala argues that attempts to eliminate diseases through wildlife control typically exacerbate problems while threatening ecosystem balance. Bats play a critical role in the ecosystem by feeding on insects, pollinating valuable plants, and dispersing seeds critical to regenerating essential forests.
“These species will never come into contact with humans and [they] pose no risk of transmitting zoonotic diseases, but [a] big part of those diseases spilling over has to do with human populations encroaching on their habitat,” Webala tells Mongabay.
Musanze caves, located in Rwanda’s far north, are a popular tourist destination, with numerous volcanic tunnels and thousands of bats, including the Egyptian fruit bat. During guided tours of the tunnels, tourists enjoy seeing the many bats hanging from the cave walls and ceilings.
However, the government closed the site in February 2025 due to the recent Marburg virus outbreak in Kigali. The virus is suspected to have originated from Egyptian fruit bats.
Mitigating the risk of “zoonotic spillover”
Scientific evidence shows that killing too many bats to control zoonotic diseases can make things worse, as the outcomes of Marburg virus outbreak in some African countries, like Uganda, and the spread of other bat-borne diseases like rabies in Peru showed.
“Measures are required to mitigate the risk of zoonotic spillover, the phenomenon where a virus, like Marburg, jumps from one species, such as bats, to humans,” Webala says.
The 2021-2023 International Union for Conservation of Nature (IUCN) Red List of Threatened Species lists 54 species of bats as occurring in Rwanda, and states that previously undocumented species are likely to occur in the country.
According to Webala, habitat loss and fragmentation due to activities such as mining, logging, hunting, agriculture and fires caused by wild honey collection pose a significant threat to the region’s biodiversity.
Due to the level of habitat change, Webala and his team say, the continued existence of rare and endangered bat species, such as Hill’s horseshoe bat, depends on accurate and up-to-date information being made available to resource managers who can utilize the data to implement effective conservation actions to protect species that are at the greatest risk of extinction.
They say they are convinced that bats are one of the most significant, yet least understood, groups of animals in the world. “These misunderstandings become compounded by dramatic movies and television, generating fear in many individuals. Though widely feared and reviled as menacing creatures of the night, bats are crucial to the health of our environment and our economy,” Webala says.
Buffer zones for protecting species
Richard Muvunyi, head of the RDB’s wildlife veterinary unit and Webala’s co-researcher, says, “We know from science that Marburg virus comes from Egyptian fruit bats, but the important thing is to understand how to live safely with these species by limiting communities’ contact with these bats in their natural habitats.”
Webala and Muvunyi say that describing all bats as sources of Marburg is wrong, as bats are a diverse group with more than 1,400 species, second in diversity only to rodents among mammals.
One of the sustainable solutions implemented by the RDB across 80 bat-listed roost sites in Rwanda to ensure bat conservation includes the design of a buffer zone of at least 50 meters (164 feet) between bat roosts and human activities.
“We are also encouraging members of local communities to plant trees around these buffer zones as a way to limit their interaction with bats,” Muvunyi tells Mongabay.
Muvunyi and Webala say that bats are predators of insects that are agricultural pests, and are, therefore, a natural asset for agrarian productivity, suppressing pest populations.
They say that without the bats’ services, plants would not be able to provide their services to humans and animals at the base of the food chain.
“Bats make up more than 40% of Rwanda’s mammal diversity, so the government is obligated to include them in the country’s conservation planning,” Webala says.
Banner image: Bats may comprise at least 40% of the overall mammal diversity in Rwanda. Image courtesy of Rwanda Wildlife Conservation Association – RWCA
Citations:
Wilkinson, G.S., Adams, D.M. (2019). Recurrent evolution of extreme longevity in bats. Biology Letters, 2019; 15(4): 20180860. doi:10.1098/rsbl.2018.0860
Flanders, J., Frick, W., Nziza, J., Nsengimana, O., Kaleme, P., Dusabe, M. C., Webala, P.W. (2022). Rediscovery of the critically endangered hill’s horseshoe bat (Rhinolophus hilli) and other new records of bat species in Rwanda. Biodiversity Data Journal, 10. doi:10.3897/bdj.10.e83546
Rocha, P., Aziz, S.A., Brook, C.E., Carvalho, W.D., & Webala, P.W. (2020). Bat conservation and zoonotic disease risk: a research agenda to prevent misguided persecution in the aftermath of COVID-19. Animal Conservation, 24(3). doi:10.1111/acv.12636
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