There are many well-known ways to keep children healthy — wash your hands often, vaccinate them, don’t smoke indoors, etc.
But there’s one thing you probably haven’t heard of: protecting bats. Literally like a flying bat.
That’s one takeaway from the extraordinary New researchPublished in Journal science, that Declines in bats are linked to increased infant mortality in the United States.
Dr. Environmental Economist compiled and analyzed a large amount of government data Yal FrankThe study’s sole author, found that in areas where white-nose syndrome, a wildlife disease that affects bats, has been hit particularly hard, infant mortality rates have increased by about 8 percent.
According to the paper there is an obvious reason for this. Most North American bats eat insects, including insects such as moths that damage crops. Without bats flying, farmers spray more pesticides on their fields, studies show, and pesticide exposure harms the health of newborns.
“When bats eat insects, farmers compensate by using more pesticides,” said Frank Voxke, assistant professor at the University of Chicago’s Harris School of Public Policy. “It has adverse health consequences — full stop. The damage from their absence seems substantial.”
Frank’s study adds to a growing body of research that supports the idea—which should probably be obvious by now—that healthy ecosystems are critical to human well-being.
Previous research Wolves have been shown to help limit car accidents by keeping deer off the road. Other studiesAlso led by Frank, the sudden decline of vultures in India is linked to an increase in human mortality. Vultures feed on animal carcasses that, if decomposed, can pollute waterways and feed on wild rats and dogs, sources of rabies.
When the link between human and environmental health is ignored, industries enabled by short-sighted policies can destroy wildlife habitat without fully understanding what we are losing in the process. This is exactly why studies like this are so critical: they reveal, to what most people can relate, how the ongoing destruction of biodiversity affects us all.
Farmers spray more when the bats disappear
Not everyone thinks bats are cute –They are! – but they are undeniably impressive. They are the only mammals on Earth that can truly fly. Also, they eat a surprising amount of bugs. A bat can catch hundreds of insects in an hour and thousands in a night.
It’s good for us: Many of the critters that bats eat during their nocturnal hunts are insects we don’t like, like blood-sucking mosquitoes and crop-eating moths and bugs. Bats are basically a natural pest control.
So it stands to reason that farmers without bats would have to use more pesticides on their crops; Agrochemicals do the work that bats do for free.
There wasn’t a great way to test this theory, until somewhat recently, when bats across North America began dying off en masse. In 2006, a fungal disease called white-nose syndrome appeared in New York state and began to spread among bat colonies, killing an average of more than 70 percent of bats. It has been brutal. WNS invades their skin, produces fluffy white growths around their noses, and wakes them up during hibernation when they should be resting. Infected bats burn vital energy stores and either freeze or starve to death.
Devastating as it may be, the rapid loss of bats has given researchers a rare opportunity to examine what happens when these creatures disappear from the landscape. In the new study, Frank — who works at the intersection of economics and conservation — analyzed data on pesticide use in the United States with and without WNS, which until recently was mostly in the eastern United States. Where there is WNS, there are probably far fewer bats.
His results were surprising: farms in areas affected by WNS used 31 percent more pesticides on their crops than in counties without the disease. This suggests that when bats disappear, farmers compensate by using more chemical bug killers.
At what cost?
The dire consequences of losing a bat
First, there are the costs to farmers. According to Frank’s study, the decline of bats cost the agriculture industry about $27 billion between 2006 and 2017, as shown by reduced revenue in areas with white-nose syndrome. The cause of this loss is unclear, although it may be that bat-free areas produce poorer crops, Frank said.
A Study A publication in 2022 supports a similar conclusion, linking the spread of WNS to a decline in the rental value of agricultural land. The idea is that farmers have lower yields or spend more money on growing crops — such as buying pesticides — when no bats provide free pest control. (I interviewed study co-author Amy Ando for an episode of the Vox Science show inexplicable. you can hear here.)
Then there is the dire value of human life.
It is well known that when farmers spray pesticides on their fields, those chemicals can enter the environment, where they pose a risk. public health. one Recent reviews Pesticide exposure in newborns, for example, has been linked to lifelong abnormalities and disease. With this in mind, you might expect areas with no bats, where farmers are using more pesticides, to have more health problems.
Frank also tested this theory, using official data on infant mortality, associated with the prevalence of white-nose syndrome. The results of his analysis were alarming: The domestic infant mortality rate — children who died from causes other than accidents or homicide — increased by about 8 percent in the county after the WNS outbreak. Put another way, when pesticide use increases by 1 percent, infant mortality increases by a quarter of a percent, which is comparable (though slightly less) to the effect of air pollution.
“I am surprised by that signal [in the data] So strong,” said Dale Manningis an environmental economist at the University of Tennessee Knoxville, who was not associated with this study. “They’re big, big numbers in terms of financial impact, but we’re also talking about people’s lives, right? And so these effects are quite significant.”
The county’s domestic infant mortality rate increased by about 8 percent after the white-nose syndrome outbreak
Manning and Ando, an environmental economist People at Ohio State University, who were not involved in the research, said the paper’s conclusions were correct. (Both Ando and Manning were involved in the 2022 study mentioned above.)
Although the study does not definitively prove that bats are the cause of the decline The study ruled out other possible forces behind the trend, including pesticide use and increased infant mortality. Frank also found that when bat declines were more severe—when more bats died, more caves were infected, or the decline was greater—the infant mortality rate was higher.
A very good reason to save nature
Such studies address creation More pressing is the ongoing decline of bat populations. In North America, more than half of all bat species “are at risk of severe population decline in the next 15 years.”2023 reportBat Conservation Alliance of North America, a coalition of groups including government agencies and Bat Conservation International. This is the trendto mirrorWorldwide
WNS is spreading west, invading new territories. Climate change is also harming these animals. The flight-adapted physiology of bats makes them highly susceptible to severe droughts and heat waves, as I have previously reported. Also, wind turbines – an important climate solution – are killing tens of thousands of bats each year in North America alone. Generally, bats, most of which are migratory species, are killed by collisions with turbine blades, although this Why is not clear These creatures are drawn to them.
It’s not all bad news; There are ways to help bat colonies survive. Scientists Tested A vaccine for WNS, for example. And Research Shows that reducing the speed of wind turbines at night during certain times of the year reduces collisions.
But these methods can be expensive — underscoring the value of studies that reveal, with greater clarity, the value of investments in conservation in both dollars and human lives.
“At the end of the day, scientists and policymakers have to justify allocating resources” to things like fixing bridges and schools, or “fixing” bats, Manning said. “All of these have different returns associated with them.”
“And if we don’t try to show the benefits of ‘fixing’ the bats,” he said, “those benefits will be discounted.”
