Stressed rattlesnakes are found to be calm in the company of a nearby person

When animals suffer acute or chronic stress, they produce more hormones that cause changes in the nervous system, immune response and behavior. Some animals, if they are in the presence of conspecifics, are able to modulate their response to buffer pressure. This is known as social buffering.

There is some research showing that snakes can exhibit complex social behaviors. However, social support in reptiles, as well as in other asocial organisms and solitary collectors, has not been studied extensively. Now, researchers in the US have examined whether the venomous snakes that inhabit Southern California use social support to relieve acute stress.

“We show that when two snakes are together and subjected to a stressful situation, they can withstand each other’s stress response, just as humans do when they experience a stressful event together,” said Chelsea Martin, a PhD student at Loma Linda University and author of the study. first of the new Frontiers in Ethology Study. “This dampening of the stress response has not been previously reported in any reptile species.”

A prop snake

When exposed to stress, the presence of a snake companion significantly reduces changes in the snake’s heart rate. Because the researchers worked with wild-caught rattlesnakes, they were able to show that social buffers most likely exist in nature and can persist in captivity.

“Our test snakes came from individual and communal overwintering populations. We found no differences in populations of snakes that did or did not overwinter within groups,” said Martin. “We also did not observe differences in social support between the sexes.”

Mountain rattlesnakes hibernate communally, which could be an indicator of a stronger social network than lowland rattlesnakes, which usually overwinter alone. It is also known that female rattlesnakes congregate during pregnancy and remain with the newborn cubs. Testing for these variables helped the researchers establish that the tendency to buffer was equally pronounced in both populations of female and male snakes.

Snake in a bucket

For their study, the researchers assessed social buffering in 25 wild-caught south Pacific rattlesnakes in three scenarios: when the snake was alone, in the presence of a leash serving as an object of dead control, and when the snake was in the presence of a same-sex companion.

Measuring a rattlesnake’s heart rate should be a reliable indicator of acute stress levels and social buffering. To get the data, the researchers equipped the snakes with electrodes near their hearts and attached the sensors to heart rate monitors. They then placed the snakes in a bucket – a dark, closed testing environment.

After a 20-minute adjustment period, the snakes were artificially disturbed. Then Martin et al. measuring the increase in a snake’s heart rate from the start, the time it took for their heart rate to return to normal, and the time they spent crunching.

Improved image for rattlesnakes

“Our results provide insight into snakes’ social behavior patterns,” says Martin. “But it might also enhance the image of the rattlesnake. In the public eye they are often slandered. Our findings can help change that,” he added.

The scientists also point out some of the limitations they are working on. For the duration of the experiment, the snake pairs were kept in a very confined space. Therefore, they did not examine whether the stress buffering response occurs when the snakes are close to, but not in physical contact with, one another. Another unknown variable, which future researchers hope to test, is whether the familiarity between two snakes influences their social buffer responses.