Restored Pumas Develop Unexpected Taste for Penguins in Patagonia

In the decades before Monte León National Park was established in 2004, pumas had been hunted to near extinction along the Argentine Patagonian coast. Livestock farmers, exhausted by losses to their sheep herds, had systematically eliminated the big cats from the region. The creation of the park finally halted the pressure, and slowly, pumas began filtering back into territory they had abandoned generations before. What no one anticipated was what they would find waiting for them: Magellanic penguins, nesting in dense colonies along the shore.

Mitchell Serota, an ecologist then at UC Berkeley, arrived in Patagonia to study how wildlife responds when human pressure lifts from former ranchland. Penguins were not part of his original research design. But the fieldwork quickly revealed otherwise. Between September 2019 and January 2023, his team deployed thirty-two camera traps throughout the park and fitted fourteen adult pumas with GPS collars. The data was unambiguous: pumas were repeatedly detected near the penguin colonies, and this behavior was not peripheral to how they hunted and moved through the landscape—it was central to it.

Magellanic penguins spend most of their lives at sea, making them an unlikely prey item for a terrestrial carnivore evolved to hunt deer, guanacos, and hares. Yet for a puma, the situation presented something almost surreal: an exceptionally rich food resource, compressed into a tiny area, but available only seasonally. The abundance of penguins did not trigger a population boom among the pumas. Density remained steady at roughly thirteen individuals per one hundred square kilometers, whether penguins were present or not. What shifted instead was the social fabric of the population itself.

Pumas that hunted penguins crossed paths far more frequently than their counterparts hunting traditional prey. Yet despite this increased overlap, territorial conflicts were fewer than expected. Emiliano Donadio, scientific director at Fundación Rewilding Argentina and a co-author of the study published in Proceedings of the Royal Society B, observed that these pumas had become remarkably tolerant of one another's presence. The explanation lay in the nature of the food supply itself. When prey is abundant and localized, defending territory becomes economically pointless. Social tolerance—a trait rarely associated with these notoriously solitary and aggressive cats—suddenly became the practical choice.

The shift toward penguin predation, however, was not entirely surprising. Jim Williams, a biologist with decades of experience in wildlife management and author of a book on pumas, notes that apex predators routinely target the most abundant and vulnerable prey available. Penguins satisfied both criteria. Patagonia also offers pumas a unique advantage: they occupy the top of the food chain with no competitors. Unlike African lions, they need not hunt in groups to bring down massive prey. Unlike their North American cousins, they face no grizzlies, black bears, or wolves forcing them into hiding. The landscape permits boldness.

Despite the predation pressure, the penguin colony has remained stable or even grown since the park's creation, according to available records. Researchers have not yet determined how many birds individual pumas kill, making precise measurement of long-term impact difficult. What is clear is that penguins have fundamentally altered where, when, and how pumas hunt. The next question concerns the ripple effects: what does this shift mean for guanacos, Patagonia's dominant herbivores and the pumas' traditional prey?

These findings challenge a foundational assumption in ecological restoration—that returning species will recreate the ecosystems they left behind. The landscape a predator returns to is never the one it abandoned a century earlier. It is profoundly altered, and the species must adapt to it. Out of these mismatched reunions, entirely new ecological relationships emerge. The pumas of Monte León are not restoring the past. They are building something unprecedented.