A new study has revealed a troubling link between the decline of bat populations and increased infant mortality rates in the United States. The research, published in Science, shows that the deadly fungus responsible for decimating bat colonies has indirectly contributed to the deaths of more than 1,300 children.

The study found that the decline of bats, which began with the introduction of the fungus Pseudogymnoascus destructans in 2006, led to a significant rise in pesticide use by farmers. Bats, which consume a substantial amount of insects, including crop pests, were no longer controlling pest populations. Consequently, farmers increased their use of insecticides by an average of 31.1% to compensate.

The increase in pesticide application has been associated with a nearly 8% rise in infant mortality in areas affected by the bat die-offs. This translates to an additional 1,334 infant deaths, according to the study. Researchers considered various other factors that could influence these outcomes, such as unemployment, the opioid crisis, and environmental conditions, but none explained the rise in pesticide use or the associated increase in infant deaths.

This study highlights an unusual and direct link between ecological disruptions and human health impacts, demonstrating the far-reaching consequences of losing key wildlife species. It reinforces previous findings about the unintended health impacts of environmental changes and pesticides, reflecting a broader pattern of how disruptions in natural ecosystems can adversely affect human well-being.