A Marine Subsidy Reshapes the Ecology of a Large Terrestrial Carnivore

Efforts to restore wildlife populations are increasing worldwide, yet many of these initiatives take place amidst significant ecological change. In extensively altered ecosystems with novel species compositions, returning wildlife may alter their behaviors and interactions with other species. In Patagonia, the extirpation of terrestrial predators following European colonization, including the puma, facilitated the establishment of colonies of Magellanic penguins along Argentina’s Atlantic coast. More recently, the establishment of a national park in coastal Patagonia has fostered the recovery of pumas and resulted in an unexpected predator-prey relationship between pumas and penguins. Using a suite of animal movement metrics and generalized spatial mark-resight models, we tested how access to the penguins affects puma behavior and abundance. Consistent with the resource dispersion hypothesis, pumas that predated penguins adapted to this novel and abundant resource by increasing their site fidelity when the penguins were present, while expanding their space use when penguins were absent. This behavioral adaptation led to frequent encounters among pumas, particularly females, suggesting greater social tolerance. Further, the park now supports the highest density of pumas recorded to date. Our work shows how the restoration of large carnivores in novel ecosystems can lead to novel interactions that transform their behaviors.