It’s a little after 5:30 p.m. At the foot of Phnom Sampov, which is located on National Road 57 about 12 kilometers from Battambang city, dozens of local tourists, sitting on folding chairs around the table of one of the refreshment stands set up along the road, are all looking at the top of this small mountain. It is not at the face of the giant Buddha carved into the rock of the mountain they are looking but at a crevice, a dark hole on the right of the Buddha. Everyone of them knows what will soon happen. In a few minutes, out of that hole will spring thousands of bats on their way to their night hunting. Around 17:45, as night falls, one, and then 10, and then 1,000, and then thousands of chiropterans fly out of the cave, forming a long ribbon that stretches in the sky. The crowd is silent, memorized by this performance of nature indifferent to humans. Every day, regardless of what happens in human history, the bats, at a set time, evening and morning, go out and return satiated to their cave of Phnom Sampov.   

Tens of meters away, in other caves, nearly 50 years ago, the Khmer Rouge were throwing the bodies of their victims or executing their alleged enemies. Were they watching, for entertainment, their crimes committed, the long, black ribbon of bats? Who could say? Nowadays, the bats give every day their performance that is fascinating for tourists and, in the end, take part in developing the attractiveness of the region.  

 But they do even more. They work, without being aware of it, for biodiversity.  

On Dec. 17, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), which is also called the Intergovernmental Panel on Climate Change (IPCC), released a report that looks into the interconnections between biodiversity, water, nutrition, health and climate change, and that highlights solutions to mitigate the effects of these crossed crises.  

On this occasion, the Foundation for Biodiversity Research (FRB) elected to highlight, based on major scientific papers published over the last few years, the chain of causality that links these different fields. With, among other questions, how the disappearance of bats in United States has led to an increase in child mortality. Why does food waste—today’s third greenhouse gas emitter after China and United States—have a major environmental impact? How does water management on a world scale threaten aquatic biodiversity as well as terrestrial ecosystems? Or also, why does the threat posed by climate change on corals compromises the crucial services they provide, especially regarding food security? 

Let’s therefore go back to our American bats and look at how, according to the Foundation for Biodiversity Research (FRB), their disappearance has provoked ripple effects on agriculture, the economy and public health. Their role is crucial for the regulation of insects and, due to their absence, farmers have increased their use of insecticides, which are far less effective, the foundation stated. The result has been a decline in the quality of the crops, a 28.9 percent drop in revenues in agriculture—$26.9 billion—and harmful consequences on children’s health. Combined damages on agriculture and health are amounting to $39.4 billion. This illustrates the interdependence between biodiversity and people’s wellbeing, the foundation stated in its report.  

Therefore, our bats of Phnom Sampov are not only useful because they perform every day a fascinating show, which is free while being profitable from a tourism standpoint. Because if this show ends up disappearing one day due to human activity, we will pay the price. We have now been warned.