Colorado checkered whiptail lizard eating a snack
carina hunting
Lizards exposed to loud noises from helicopters and fighter jets flying overhead eat less stress and spend less time in the sun.
Megen Kepas and her colleagues at Utah State University studied the behavior of checkered whiptails in Colorado (Aspidoscelis neotesselatus) lives at Fort Carson US military base near Colorado Springs. Apache, Chinook, Black and his Hawk helicopters and his F16 fighter jets operate from the base, so the researchers wanted to see if they influenced the lizard’s behavior.
To facilitate a study conducted in 2021, US military pilots flew over test areas on certain days and avoided them on other days. It was 112.2 decibels (about the size of a chainsaw at a meter away), but otherwise the maximum level was only 55.8 decibels. This is approximately the noise level of a refrigerator.
After observing their behavior for three minutes, the researchers caught a total of 82 lizards, which are considered species of special concern by Colorado Parks and Wildlife.
Lizards, an all-female species that reproduces asexually, spend less time moving around and more time eating when exposed to aircraft noise. Kepas and her colleagues then weighed the reptiles and took blood for hormone testing. It found that levels of the stress hormone cortisol increased after an aircraft flyover.
Researchers suggest that when a lizard’s stress level increases, the body’s energy needs increase, and it must spend more time eating to compensate. To mitigate the impact, they recommend that the U.S. Army limit the noisiest flyovers.
Richard Griffiths of the University of Kent, UK, said that while the finding was interesting, it could be useful to observe a control sample of lizards that had never been exposed to aircraft noise. increase.
He says the lizards usually scatter and hide when disturbed. Aircraft noise is probably so ubiquitous on the base that the reptiles there “have had to get used to it,” he says.
“If they’re used to this, and they’ve learned that these noises aren’t causing problems in terms of reduced viability, it just boils down to these physiological responses. You get a compensatory diversion of behavior to eating,” says Griffiths.
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