Culling bats isn’t the way to control Hendra virus

Fruit bats carry disease, pollen and a warning about the state of the environment. shellac/Flickr

This year has had the lot. First came the tempest, then the floods. Fires are on their way as the landscape dries out.

Now we have pestilence, in the form of Hendra virus. Calls for bat culls have ensued, but killing or relocating bats could make things worse for everyone.

Vital pollinators: bats carry more than diseases

Hendra virus is one of a number of recently emerged viruses which has spilled over from its usual wild-animal-hosts to domestic animals, and then to us.

Hendra’s repeated appearance this year has caught public attention. Sadly much of that attention has not focused on the rarity of the disease or that transmission to humans occurs from exposure to sick horses.

Instead, it has focused strongly on control of the reservoir host of the virus: flying foxes.

Flying foxes are large bats found in forests along the whole of the east coast of Australia. They are important pollinators, and disperse the seed of native trees and shrubs.

In many environments, they are better at these tasks than birds, insects or the wind. In the wet tropics of northern Queensland, flying foxes help maintain the world heritage values of the tropical rainforest.

Cute, furry, useful and hated

Despite their ecological value, flying foxes are roundly disliked, especially by the citizens of towns which share space with a flying fox colony.

A recent paper by Dominique Thiriet analyses the effect of unpopularity on species management. Shorn of academic niceties, she concludes it is hard to “sell” the value of creatures people dislike and even harder to implement science-based management regimes that conflict with the wisdom of public opinion.

Each time a disease crosses from bats to humans, there are immediate and sustained demands for bats to be culled or relocated from their roost sites.

These are rash ideas. There is a growing body of research that suggests relocation or culling will not reduce bat-associated disease and may even make matters worse.

The basis for this argument lies in the wider domain of One Health, an idea which links human health and welfare to the health of the natural world.

Bat illness can lead us to the bigger picture

Overseas, spillover of viral diseases from bats has contributed to outbreaks of Nipah virus, SARS and Ebola virus. In each instance, the spillover has occurred in places with close associations between humans, their animals and bats in landscapes experiencing severe environmental stress.

Culling won’t cure Hendra. onkel_wart