As the Democratic Republic of Congo grapples with another Ebola outbreak, bats have once again come under scrutiny as a possible reservoir for the virus. But according to bat ecologist Paul Webala, there is no conclusive scientific evidence linking bats to Ebola and the natural reservoir remains unknown.
The current Ebola outbreak is caused by the Bundibugyo strain, a variant for which there are currently no approved vaccines or treatments, according to the World Health Organization.
In this interview with Mongabay, Webala discusses why bats are often misunderstood, details the important ecological services they provide, and explains why habitat destruction may pose a greater risk for zoonotic diseases that spill over between animals and humans than bats themselves.
Webala is a wildlife biologist at Maasai Mara University in Kenya who has studied bats for more than two decades.
Mongabay: Many people immediately think of bats whenever there is an Ebola outbreak. Are bats unfairly stigmatized?
Paul Webala: Bats are the second-largest group of mammals after rodents. Roughly 25% of all mammal species are bats. They play extremely important roles in ecosystems and are an integral part of biodiversity. Remove them, and entire ecological systems could begin to collapse.
Unfortunately, bats are associated with many myths and misconceptions. Some communities associate them with death, evil spirits or bad omens. Because of these longstanding beliefs, bats have often been persecuted. When you add zoonotic diseases to the equation, the negative perception becomes even stronger. The reality is that many animals carry pathogens, including livestock, pets and wildlife. Bats are not unique in that regard.
The problem is that much of what appears in the media is driven by incomplete information. Even scientists still have a lot to learn about these animals.
Mongabay: Some scientists describe certain bat species as potential reservoirs of Ebola. What does the evidence actually show?
Paul Webala: The key word is “potential.” As we speak today, there is no conclusive evidence that bats are the source or reservoir of the major Ebola viruses affecting humans.
Researchers have found antibodies in some bat species, but finding antibodies simply means an animal has been exposed to a pathogen. It does not mean that species is the source of the disease.
Since the major Ebola outbreaks in West Africa and Central Africa, thousands of bats have been sampled and tested. Despite extensive efforts, scientists have not conclusively identified bats as the reservoir of Ebola. In fact, we still do not know with certainty which animal species serves as the natural reservoir for Ebola.
So, when people state categorically that bats cause Ebola, they are going beyond what the science currently supports. Much of that remains speculation rather than established fact.
Paul Webala: The consequences are serious. Since COVID-19, bats have been persecuted across many regions. Colonies have been burned out of caves. Roost sites have been destroyed. Trees used by bats have been cut down. This is dangerous because bats provide essential ecosystem services.
Many bat species consume enormous quantities of insects every night. Some of those insects are agricultural pests, while others are disease vectors such as mosquitoes. By naturally controlling insect populations, bats save farmers millions of dollars in avoided crop losses and pesticide use.
Other species, particularly fruit bats, are vital seed dispersers. They move seeds over long distances and help restore forests in degraded landscapes.
They also pollinate numerous tropical plants. One of the most famous examples is the baobab tree, often called Africa’s “tree of life.” Much of its pollination is carried out by bats.
Without bats, many of these ecological functions would be weakened or lost.
Mongabay: Some people argue that if bats carry diseases, eliminating them would reduce risks to humans. Is that true?
Paul Webala: Quite the opposite. The real driver of emerging infectious diseases is often habitat destruction. When humans destroy natural habitats, wildlife is forced into closer contact with people. That increases opportunities for pathogens to spill over.
