California ground squirrels caught hunting other animals in a shocking, rare footage | Watch

These ground squirrels of California, so familiar in the backyard where they can often be seen nibbling on seeds and nuts, have recently been documented in a behaviour that scientists term "shocking": hunting and eating other animals. For decades, the bushy-tailed rodents had been considered strictly granivorous; most of their nutrition and energy came from plant-based foods. But a joint study by researchers from the University of Wisconsin-Eau Claire and the University of California, Davis has found that these squirrels are actually opportunistic omnivores and can prey on voles if the circumstances provide. Observations from June to July revealed that nearly half of the captured interactions involved active hunting, particularly during periods of peak vole populations. This discovery challenges long-standing assumptions and opens new questions about the ecological adaptability of this common species.

California ground squirrels display unexpected hunting behaviour in the wild

According to the study published in Springer Nature Link, the behaviour was first observed by undergraduate students doing fieldwork in local Californian parks. Jennifer E. Smith, the lead researcher and associate professor of biology at UW-Eau Claire, said that she was surprised to observe squirrels hunting voles. "We had never seen this behaviour before," Smith said. "Squirrels are one of the most familiar animals to people. Yet here was a completely new behaviour, revealing that there's still so much to learn about even the most common creatures around us."

From June 10 to July 30, the researchers monitored 74 interactions by squirrels and found 42% involved the direct predation of voles. Notably, the peak of carnivorous activity coincided with an explosion in vole numbers reported. This would hint that food availability is a strong driver of dietary choices among squirrels.

California ground squirrels reveal a flexible survival strategy

Findings of this study show that California ground squirrels are much more behaviourally flexible than previously believed. According to Sonja Wild, a postdoctoral research fellow at UC Davis, these rodents behave like other opportunistic omnivores such as raccoons, coyotes, and even humans. “These squirrels are incredible opportunists,” Wild said. “When food availability changes, they can adapt quickly, exploiting new resources to survive and thrive.”

By preying on voles, squirrels gain access to a rich source of protein, which may be particularly important during times of low plant-based food or high competition. This behavioral flexibility allows them to adapt to changing environments-a valuable trait in increasingly human-dominated landscapes.

California ground squirrels reveal a more complex role within local ecosystems

This rather omnivorous-like behaviour fundamentally changes scientific understanding regarding the carnivorous habits of California ground squirrels. Now viewed by scientists not just as harmless seed-eaters, but taking on a far more dynamic ecological role, their presence could very well have significant effects on local vole populations and other predators that share their environment. This study raises some fundamental questions, such as how frequently squirrels hunt, whether this behaviour is seasonal, and if it has a hereditary component.

Moreover, such an ability to turn to other diets, as the environmental ones change, may allow these squirrels to persist in a rapidly changing habitat where human activity has altered the ecosystems and affected the traditional sources of food.