Infant mortality rate and bat population decline may have strange correlation, study says

In 2006, a fungal disease called white-nose syndrome began to decimate bat populations across New England. Over the next decade, the loss of these bats, vital for keeping insect populations in check, led to serious consequences for agriculture and human health, according to a new study. With fewer bats to eat the insects, farmers began using insecticides, resulting in a 31 percent increase in pesticide use, according to the report. That increase was associated with an 8 percent increase in infant mortality in affected areas.

Impact on agriculture and human health

Bats play a key role in natural pest control, with some species eating about 40 percent of their body weight in insects each night. Researchers led by economist Eyal Frank of the University of Chicago noted in their study published in the journal Science that when bat populations plummeted, farmers responded by using more insecticides to compensate. The additional use of insecticides increased by about 2 kilograms per square kilometer over five years. Meanwhile, the use of fungicides and herbicides remained unchanged.

Infant mortality is rising

The study found a disturbing link between the increase in insecticide use and the increase in infant mortality, particularly in deaths related to disease or birth defects. But other factors, such as accidents and homicides, did not show a similar increase. Winifred Frick, chief scientist at Bat Conservation International, expressed shock at the results, calling them a significant finding.

Tracey Woodruff, an environmental health scientist at the University of California, San Francisco, said a link between pesticides and infant health risks is likely, citing similar findings from previous studies on air pollution, according to a report by Science.org.

Challenges and future prospects

While bat populations are slowly recovering, it could take decades to reach previous levels. Conservation efforts are underway to help rebuild them, including attracting insects to hibernation sites and improving roosting conditions.