The coasts of Argentina have for decades been the scene of an epic clash between local pumas and rancheroswhose flocks were an easy fast food for felines. In the end the war was obviously won by the humans, who made the pumas disappear from the coast by hunting them.
The big cats returned only in 2004, with the birth of Monte León National Park, and since then something has changed in their habits, as described in a study published in Proceedings of the Royal Society B. The protagonists of this change, which is revolutionizing the ecosystem and the way pumas inhabit it? Tens of thousands of penguins.
The return of the pumas. With the disappearance of pumas from the Argentine coasts, Magellanic penguins have begun to populate the area: they spend most of their lives at sea, but every year, between September and April, they return to shore to breed. And they do it in large quantities: in the Monte León park alone there are more than 40,000 pairs concentrated in a couple of kilometers of coast. Upon their return, the pumas therefore discovered that, at least for a few months a year, their old home is now transformed into a all you can eatwith abundant prey and above all very easy to hunt.
The study. Researchers at Fundación Rewilding Argentina witnessed the first cases of predation in 2023, when they published a study that described them as “minor”, more anecdotal than anything else. When in doubt, however, the team installed 32 camera traps and tracked the movements of 14 adult pumas with the use of GPS collars, to find out if their interactions with Magellanic penguins were more frequent than they thought.
More food, less beating. The answer, of course, is yes: pumas spend a lot of time hanging around the penguin colony, and episodes of predation are numerous. This is radically changing the way pumas inhabit the Argentine coasts: they spend much more time near the sea, and above all they don’t fight with each other. Pumas are usually solitary and very territorial animals, which often clash with invading rivals; the “coastal” felines, on the other hand, have shown that they can tolerate each other much more, and that they know how to share the territory without “slaughtering each other”.
The colony resists (for now). The reason is easy to understand: when food is plentiful, concentrated and easy to access, it is useless to waste energy fighting with rivals, because there is nothing to defend.
A hypothesis confirmed by the fact that the other Argentine pumas, those who have not changed their diet and still feed mainly on guanacos, have not lost an ounce of their mutual aggression.
And what about Magellanic penguins? The latest data say that the Monte León colony is still numerous and is actually growing compared to past years: at least in the short term, they do not seem to be damaged by the increase in predation.
