THIS striking image by photojournalist Adam Dean shows bats streaming out of Khao Chong Pran cave in Thailand at dusk as researchers collect individuals to study.

The cave, the largest of several in a cluster west of Bangkok, is a popular tourist spot because millions of bats flock there to roost. Now scientists from Thailand’s Department of National Parks, Wildlife and Plant Conservation are becoming frequent visitors, too.

More than a year after covid-19 was labelled a pandemic, we are still trying to discover definitively whether the SARS-CoV-2 virus originated in bats. Researchers are collecting tissue samples from bats and checking local people – some of whom use bat droppings as fertiliser – for covid-19 antibodies. The viruses that cause severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) came from bats, and a virus similar to SARS-CoV-2 was found in horseshoe bats in Cambodia and China in late 2020.

There are concerns that urbanisation and agriculture are destroying or infringing on bat habitats, making the animals more susceptible to viruses and increasing the chances of them passing diseases to us.