Rattlesnakes: Social Creatures?

Summary: Rattlesnakes are solitary animals. Are you sure? Join Kiersten as she turns what we know about rattlesnake lifestyles on its head. 

 

For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean

 

Show Notes:

America’s Snake: The Rise and Fall of the Timber Rattlesnake by Ted Levin

“Social Lives of Rattlesnakes”, by Rulon Clark. Natural History, March 2005.

“Kin Recognition in Rattlesnakes,” by Rulon W. Clark. Proc. R. Soc. London B (Suppl.) 271, S243-S245 (2004), DOI:10.1098/rsbl.2004.0162

“Social Security: can rattlesnakes reduce acute stress through social buffering?” By Chelsea E. Martin, Gerad A. Fox, Breanna J. Putman, and William K. Hayes. Front. Ethol, 06 July 2023, Vol 2, 2023. DOI:doi.org/10. I 3389/fetho.2023.1181774

Music written and performed by Katherine Camp

 

Transcript 

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Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.

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Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 

This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.

The title of this episode might be a bit of a shock to you. Why are we talking about social structure in snakes? They’re solitary animals, right? Well, social structure is the sixth thing I like about rattlesnakes and it totally flipped the script on these interesting reptiles.

In general, when we think about reptiles we think of solitary animals that do not share territory, dens, or any part of their life with other reptiles of the same species. This is especially true of snakes. But maybe we’ve been wrong about this assumption. Those of you that have listened to the reproduction episode already know that mothers will share a den with their young after they’ve been born until their first shed. This was a completely unexpected behavior when we first discovered it, so we shouldn’t be too surprised to learn that rattlesnakes are social in other ways, as well.

Recent research has shed light on the social behaviors of snakes outside the natal den and, I hope you’re sitting down for this episode, because it’s going to rock your world!

In the March 2005 issue of Natural History magazine, an article titled “Social Lives of Rattlesnakes” was written by Rulon Clark. Most likely many people scoffed at the title and if they read the article at all, they certainly didn’t believe the information contained within. 

Quoting form the article, Clark says “Timber rattlesnakes live as long as thirty years in the wild, and they seem to live as stable, cooperative community members. They appear to form lasting relationships with other individuals, follow similar paths through the woods, bask together before shedding their skins under the same fallen log, and sometimes follow each other from one den to another.” I can just hear the scoffs and see the bug=eyed disbelief, but since this article was published more studies based on Rulon Clark’s research have proven him right. 

Let’s take a look at what Mr. Clark wanted people to learn about rattlesnakes when he wrote this article. Timber rattlesnakes are of great concern to anyone who loves rattlesnakes. They are native to the east coast of the Untied States and have been in decline for a very long time. Many rattlesnake researchers focus their interest on these snakes so that we can learn everything about them before they disappear forever. 

Certain northeastern states are the only stronghold left for the Timber rattlesnakes. Now you probably don’t expect an ectothermic animal to live in an area that has weather cold enough to snow every year, but they do. The way they survive is to hibernate in a den that keeps them protected from the elements. They share these dens with other Timber rattlesnakes. Let me say that again. This animal that is often thought of being solitary, shares hibernation dens with other individuals of the same species. They head to den sites around mid-October and they usually emerge in early May. Genetic research done on some of these denning sites has shown that the groups that overwinter together tend to be closely related kin.

Okay. Okay. I can hear you doubting this. Maybe you think the snakes are just returning to a place they know is a safe denning site that other clutch mates also know about. That could be true and it is probably one of the reasons that siblings are often found in dens year after year, but  that doesn’t explain why they may be found in the same sunning sites or shedding together under the same fallen logs.

There is evidence that snakes do recognize their own kin. In experiments performed with snakes born in captivity to wild caught mothers, female Timber rattlers were found to spend more time closer to related females than unrelated females. The test subjects did remain together with their mother and siblings until they shed for the first time, which typically takes a bout a week. Then the individual snakes were separated from each other for two years after they shed their natal skin. Three separate clutches were used. After two years of isolation,   rattlesnakes were placed in an enclosure with plenty of room to stay away from each other if they chose. They tested the snakes in pairs, Female and female kin, female and female non-kin, male and male kin, and male and male non-kin. They distance between them was recorded several times a day. 

Results showed that female kin choose to spend time closer together than   non-kin. 

Socializing with your kin is one thing but what about individuals that are not your relatives? There is plenty of evidence of that too. Timber rattlesnakes have been seen sunning themselves together, pregnant females congregate and birth in the same areas, they leave chemical trails that neonates can follow to find winter hibernacula, and social rattlesnakes emit an alarm pheromone when predators encroach. All of these things point to adaptations of a societal lifestyle. 

A scientific paper published in July of 2023 asked the question of whether rattlesnakes can benefit from emotional support. Okay, they didn’t exactly say that but they did ask if rattlesnakes could reduce acute stress through social buffering. According to PubMed Central, social buffering is the phenomenon by which the presence of a familiar individual reduces or even eliminates stress and fear induced responses. 

Using Pacific rattlesnakes caught in the wild, the researchers handled them, which is a known stressor for wild caught rattlers, and then placed them in a container alone, or with a coiled rope, or with another Pacific rattlesnake. Monitoring their heart rates with electrodes, the researches timed how quickly the snakes relaxed into a normal heart rate again. The snakes placed in the enclosure with another snakes recover from their stressful encounter faster than the ones left alone or with the copied rope. 

It blew my mind when I read this paper! I hope that this episode about rattlesnakes has changed the way you think about this reptile because it’s my sixth favorite things about them.  

If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 

 

Join me next week for another episode about rattlesnakes.  

 

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This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.