Friends with Benefits: New study finds that garter snakes are socially organised

Snakes occupy a particularly negative position in human consciousness. They are seen as mindless, anti-social, malevolent creatures. Something to be feared and difficult to relate to. A recent finding, however, adds to the growing proof that the lives of snakes are far more complex – and far more social – than we typically give them credit for. Scientists worked with 12 years of data to come to the surprising conclusions that Butler's garter snakes actually form sex- and age-based social networks.

Turns out Butler's garter snakes are a lot more social than we thought.

The study, conducted by Dr. Morgan Skinner and a research team, and set to be officially published in February 2024 in the journal Behavioral Ecology, is part of a growing body of research about the often-hidden lives of snakes. The paper starts out by establishing that “very little is known about the social structure of snakes” which is likely because “snakes are often considered non-social animals and are particularly difficult to observe in the wild”. After all, unlike typical subjects of social research – think orcas, humans, rodents, etc. – snakes do not openly congregate. They much rather prefer hanging out far from prying eyes and predators. So, how did this research team manage to get a look at these socialising serpents?

Surprisingly, they did not employ any radically new technologies or methods to access the cryptic creatures. Rather, the team ‘visualised’ social networks of garter snakes using computer programs based on conventional catch-and-release data collected in a separate study. This separate study took place from 2009 until 2020 and was initially carried out to monitor the population of garter snakes in an area undergoing road construction.

Snake are not considered social animals and little is known of their social behaviour in the wild, however, a new study shows that Butler's garter snakes are socially organised.

The reptilians were captured, weighed, measured, and had their sex determined before being relocated 50 metres away, outside of the construction zone. Importantly, the exact location and time of the capture was also recorded. Skinner and his team determined that if multiple snakes were captured within 50 metres and 14 days of each other they likely have some kind of association. This is because snakes have a keen sense of smell and pick up on the scent trail of other snakes that have been in the same area within two weeks. Using this criterion, the team analysed how commonly snakes ‘associated’. 

The scientists’ data analysis illuminated some quite interesting patterns. First, the social structure of garter snakes is not randomly organised. Rather, snakes seek out and prefer to hang out with other specific individuals – basically, they have common acquaintances. Second, garter snakes associate most with other snakes of the same sex and similar age. Older female snakes have the most ‘friends’ and are often the central figures in their communities. In fact, other younger snakes follow older females around. The team also found that as males age they become less social. The researchers suggest that sexually mature males may try to reduce direct competition with other males and thus prefer to hang out alone. That being said, some males – especially younger ones – do still routinely socialise. 

One of the most fascinating discoveries from the research is that being part of a snake community may come with health benefits. The scientists observed that snakes who were part of a social network had a better body condition compared to snakes who were loners. This finding suggests that there is an evolutionary incentive for garter snakes to associate together. The researchers proposed that snakes might benefit from community membership through greater protection from predators, temperature regulation, and/or being able to share and receive useful information (like good spots to shelter). That being said, the study’s authors emphasise that this relationship is one of correlation, not causation. Although it may be the case that snakes benefit from social ties, it could also simply be that healthier snakes tend to congregate whereas less healthy snakes prefer to be alone – perhaps to avoid competition. 

The study – “the most extensive field study of snake sociality ever carried out”, according to an article in Science – marks a new era of snake research. “It’s a whole new avenue of research that I don’t think people have really given any thought to”, Dr. Robert Mason of Oregon State University told Science. It proves that snakes may not be the anti-social loners they are often portrayed as and it offers a creative, simple, methodology to study the hidden lives of these generally shy reptiles.

Header image: Jen Goellnitz