Here’s Why It’s Actually Good for Them

Cannibalism is often viewed as a rare and unnatural occurrence in nature, particularly among snakes. However, a recent study published in Biological Reviews has uncovered that cannibalistic behavior in snakes is far more common and complex than previously thought. The research, which analyzed over 500 reports across various snake species, reveals that cannibalism has evolved independently at least 11 times throughout snake history.

The Surprising Discovery Behind Snake Cannibalism

The study published in Biological Reviews has revolutionized how scientists view snake behavior. Over 503 reports from 207 snake species across different continents were reviewed, revealing that cannibalism is not a rare anomaly but a recurring strategy in various snake families. The study, led by Bruna Falcão from the University of São Paulo, provides compelling evidence that cannibalism among snakes may occur as an adaptive response to environmental stressors such as food scarcity. Falcão told LiveScience,

“For us humans, we don’t think of cannibalism as something common –– it’s something weird and disgusting. But for snakes, it’s good for them; it’s good for their ecological fitness. … It’s strategic.”

The research shows that cannibalism is widespread in snake species across the world, from those in captivity to those living in the wild.

Why Do Snakes Resort to Cannibalism?

Cannibalism in the animal kingdom is often linked to a need for survival, whether through food shortages, population control, or opportunistic predation. Snakes are no exception. The study found that snake species from families like Colubridae, Viperidae, and Elapidae often engage in cannibalism, especially during times of food scarcity. This behavior is particularly notable in species with flexible diets, such as generalist eaters who are able to consume a wide variety of prey.

One of the key findings of the study is that cannibalism is most commonly observed in snakes during stressful conditions. These stressors can include limited access to food, competition with other snakes, or even environmental changes that make hunting for traditional prey difficult. As Falcão explains,

“None of us expected that … snakes could be so cannibalistic, and no one was talking about it. The more we were searching, the more cases we found.”

This reflects how researchers are now beginning to understand that cannibalism can be a strategic, survival-based response rather than an unusual, incidental event.

In captivity, where snakes are confined to small spaces with limited food sources, cannibalism seems to be even more common.

Evolutionary Advantages of Cannibalism in Snakes

Cannibalism in snakes is not simply an act of desperation; it can offer significant evolutionary benefits. Snakes that engage in cannibalism can help control their populations by removing weaker individuals, thereby ensuring that only the fittest survive. This behavior also plays a critical role in maintaining ecological balance in their habitats. In times of limited resources, consuming other snakes can provide the necessary sustenance for survival, particularly in environments where food is scarce.

While it might seem counterintuitive, cannibalism helps maintain a healthy population by reducing competition and ensuring that only the strongest snakes survive to reproduce. This process also helps regulate the snake population in relation to the available resources, preventing overpopulation and its negative effects on the ecosystem. However, experts like Xavier Glaudas, who was not involved in the study, are cautious about the relationship between generalist species and cannibalism. “In regard to the idea that cannibalism could be more common in generalist species, I am a bit more skeptical about the data presented,” Glaudas  told Live Science. This skepticism highlights that while cannibalism is widespread, the underlying causes are still being debated.