In Argentina’s Monte León National Park, the recovery of pumas, the top terrestrial predator, has created surprising behavior that transforms our understanding of the species’ social structure. The pumas preying on Magellanic penguins along the Patagonian coast show a novel ecological interaction with significant consequences. The findings have been published in The Royal Society’s flagship biological research journal.
December 17, 2025—COMODORO RIVADAVIA, AR As the population of pumas (Puma concolor) recovered in a coastal sheep ranch turned national park, researchers discovered an unexpected ecological interaction: the pumas began preying on penguins, triggering surprising changes to the behavior of the apex predator. The findings have been published in the article, “A Marine Subsidy Reshapes the Ecology of a Large Terrestrial Carnivore,” in the journal Proceedings of the Royal Society B: Biological Sciences.
In 2004, when conservationists Doug and Kris Tompkins donated 170,000 acres to the Argentine government to create Monte León National Park along the Patagonian coast, thousands of Magellanic penguins inhabited the property. Following the park creation, other wildlife began to rebound, including Patagonia’s largest terrestrial predator, the puma.
Over several years, Mitchell Serota and Dr. Arthur Middleton, Associate Professor at the University of California Berkeley, worked with Dr. Emiliano Donadio, National Geographic Explorer and the Science Director of Rewilding Argentina, to study the novel interaction between penguins and pumas. Their team captured, collared, and monitored 14 adult pumas across the park and deployed a large camera trap array to estimate puma density and assess their behavior. Together, these methods allowed the researchers to quantify how pumas moved, interacted, and responded to the seasonal arrival of penguins.
Analyzing four years of GPS and camera data, Dr. Serota found surprising results. During the penguin breeding season (September to March), pumas preyed heavily on penguins which had dramatic effects on puma movements and social interactions.
Pumas that preyed on penguins interacted with other pumas up to five times more than those that did not, suggesting that the abundant, clustered prey resource made them more tolerant of each other. The penguins anchored pumas to smaller territories: when penguins seasonally migrated, pumas responded by quickly expanding their movement. In addition, the results revealed that penguins, together with guanacos, help support an abundant and healthy population of pumas, highlighting the importance of native prey to native predators.
Penguins, historically not abundant to the coast of Patagonia, represent a novel prey for pumas. European settlements brought the eradication of predators, including foxes and pumas, allowing penguins to colonize the continental coast and form large breeding colonies. When Monte Leon became a national park, pumas recovered and found a new easy-to-catch prey.
“This study shows how a single, abundant prey species can reshape the behavior and ecology of an apex predator,” says Dr. Serota. “As carnivores recover in landscapes that have changed since their absence, they may adapt in ways that challenge our long-held assumptions about these solitary predators.”
Dr. Donadio emphasizes the broader implications: “When pumas kill and consume penguins, they are obtaining nutrients that originated in the ocean. The large number of penguin carcasses decomposing on land releases marine nutrients into the soil, linking two different realms — ocean and land — and likely benefiting a myriad of other species beyond pumas.”
Sebastian Di Martino, Conservation Director of Rewilding Argentina, is optimistic about the findings, saying, “The recovery of large predators and their prey in the Patagonian steppe can remedy the imbalance that humans have caused in ecosystems. In Monte León, as in other national parks in Argentina, nature is following its course, now with all the necessary ingredients in place.”
This research was a collaborative effort between the University of California Berkeley, Rewilding Argentina, and the Argentine Research Council (CONICET) with logistical support from the Argentine National Parks Administration and funded by the National Geographic Society. Rewilding Argentina is non-profit organization that seeks to restore the functionality of degraded ecosystems through rewilding and the creation of protected areas.