The real-life rivalry of bats and penguins

In the wild, penguins aren’t notorious mobsters, but they are fierce protectors—and will fight bats if they need to. 

In the Atacama Desert of southern Peru, Humboldt penguins can become the target of vampire bats, whose main source of food is the blood of other animals.

Although vampire bats in this region typically choose to prey on nearby sea lions, they sometimes hunt penguin chicks, who put up less of a fight than other prey. Also, compared to older penguins, they are much more oblivious to the dangers vampire bats pose. 

“Vampire bats are very cautious when they are feeding because they have to feed on a much larger animal almost every night of their life,” says Gerald Carter, an associate professor of ecology and evolutionary biology at Princeton University.

Bats and penguins typically live in completely different areas of the world. Vampire bats normally don’t fare well in cold temperatures, preferring to live in both arid and humid locations like rainforests or deserts. However, they’re comfortable enough in the dry west coast of South America, where Humboldt penguins also reside. These two species may have silently been at odds for a while—some experts believe penguins might at one time have been the bats’ primary food source.

“Vampire bats have probably long fed on aggregations of breeding sea birds and other animals along the coasts of Latin America before livestock were introduced,” says Carter.

Because Humboldt penguin populations are decreasing, conservationists consider the species especially vulnerable to the risk of extinction. Vampire bat populations in the area, on the other hand, are considered stable by the International Union for Conservation of Nature.

Vampire bats’ attacks on the vulnerable penguins can lead to blood loss or the spread of diseases like rabies, both of which could weaken penguin chicks or endanger other members of the rookery. But that doesn’t mean these penguins are without ways to defend themselves.

Humboldt penguin adults have multiple ways of shooing these  old enemies away, either by vocalizing their displeasure directly to scare the bat into flying off, kicking dirt in the bats’ faces, or in some cases, by weaponizing their poop. It’s a tactic that Humboldt penguins are well known for, but the technique can be hit or miss.

Of course, while getting projectile-sprayed with poop would make any persistent predator pause, more times than not, it’s the chicks who are left bearing the brunt of the mess, waddling away to rinse off in cold waters.