When they hear noises that are too loud, such as airplanes, some lizards tend to ingest larger quantities of food, according to a new study. This is a defence mechanism against stress, but it is not enough to protect them completely, especially during the breeding season.

In times of stress or when confronted by situations that generate a feeling of anxiety, many people seek comfort through food. The phenomenon is so widespread that it has been given the term “stress eating”.

And while the parallel may seem surprising, humans aren’t the only ones who take refuge in food in a bid to soothe these emotions. Researchers from Utah State University have found that some species of lizards adopt a similar pattern of behaviour.

The reason, however, turns out to be somewhat different: these reptiles react in this way when confronted with the harmful effects of noise pollution caused by humans.

The authors of this study analysed blood samples from lizards of the “aspidoscelis neotesselatus” species, which is found mainly in the United States, particularly in the state of Colorado, and is commonly known as the Colorado checkered whiptail.

In the course of their research, they found that cortisol and ketone levels were particularly high after airplanes passed close to these lizards. They also deduced that to protect themselves from these loud noises, the reptiles tended to adapt their behaviour and ingest larger quantities of food.

The researchers thus concluded that the Colorado checkered whiptails seem to have found a way to compensate for the potentially negative effects of noise from aircraft, which frequently fly over their habitat area given its proximity to a military base.

But “they still appear to suffer a metabolic cost driven by the stress response via ketone accumulation”, particularly observed in the smaller animals, and even more so if the noise disturbance occurs during the breeding period, the study states.

Lizards are not the only species to be harmed by anthropogenic noise disturbances. According to this study, “Mexican spotted owls have also shown to initiate a significant response to noise disturbance as low as 68 decibels”.