Pumas vs. Penguins: The Surprising Land Grab in Patagonia
The Battle for Territory: Pumas vs. Penguins
When you think of predators that penguins might fear, killer whales, sharks, and seals might come to mind. Perhaps polar bears, if you've mixed up the Antarctic and Arctic. But few would consider pumas as a threat to penguins.
However, researchers from the University of Oxford have discovered a surprising territorial dispute in the Patagonia region of Argentina, where pumas are increasingly preying on penguins. Over the past century, Magellanic penguins have migrated to the Argentinian mainland from Atlantic islands, largely due to the absence of terrestrial predators. But this safety from predators has been short-lived.
The Return of the Pumas
Cattle-ranching was largely abandoned in southern Argentina in the 1990s, allowing pumas to recolonize their historical ranges in the area. This brought them into contact with Magellanic penguins for the first time, and the penguins, being largely defenseless, became an easy target for the large carnivores.
Over a four-year period, pumas in the Monte Leon national park on the Patagonian coast killed more than 7,000 adult penguins, accounting for almost 8% of the adult population. In many cases, the pumas are not killing the penguins for food, leaving their carcasses mostly uneaten. This suggests that the pumas are engaging in 'surplus killing', a behavior where predators kill more prey than they need for food.
The Impact on Penguin Colonies
The penguin colony in the park was under threat, but more from low breeding success and reduced survival rates of young penguins than from the puma threat. The data behind the study was collected from 2007 to 2010, but has only now been analyzed to examine the impact of puma predation. Researchers say that the largest colonies in the region are likely to be resilient to puma predation, but smaller colonies may be at greater risk.
The Surprise of New Behaviors
Scientists often find themselves surprised to observe new behaviors when changes in human activity lead two species of animal to be brought together in the same territory for the first time, or for the first time in centuries. For example, a killer tortoise was observed for the first time in 2021, with footage recorded in the Seychelles of a tortoise hunting and then devouring a tern chick. The species had previously been considered a strict herbivore.
The Controversial Question
This raises the question of whether the hunting is a newly developed behavior in the tortoises, or whether they are reviving a lost art. Conservation efforts in the islands have led tortoise and seabird populations to increase to levels not seen in centuries. This controversy invites discussion and encourages readers to share their thoughts in the comments.
