This story ends well for the penguin. Based on this photo (below, recently taken by Laurielle Penny), however, it looks like things could have been a heck of a lot different. In the foreground is a Chinstrap – a mid-sized penguin of about 10 pounds; in the background is a Leopard Seal – a marine behemoth (up to 1300 pounds) that has a particular affinity for mid-sized penguins like Chinstraps. How, then, did this Antarctic encounter play out with so little fanfare?

Chinstrap and Leopard Seal

Being so out in the open and, as a result, so visible to the seal might seem like a problem for the penguin. Leopard Seals are, after all, powerful swimmers that can usually move quicker than the flightless birds. A penguin underwater, however, can maneuver with torpedo-like bursts of speed and abrupt changes in direction. A Leopard Seal could well catch up to and capture a penguin in an all-out chase, but energy-wise, it would come at a cost. It may then be to this Chinstrap’s advantage that it is in such an unobstructed position in relation to the seal and in a patch of open sea. The chase might just not be worth the while for this seal.

Leopard Seal

A hulking predator with major energy needs still needs its calories, though, so what is the alternative to jumping in the water and chasing this Chinstrap? Well, interestingly enough, the alternative may well be another Chinstrap – that is, another Chinstrap in a vastly different situation.

In the Antarctic summer, where you see one Chinstrap, you likely see a few more – 100, 000 or so more in some colonies. Parents in a mated pair share incubation and chick-tending duties, so adults are forced to come ashore…and then return to the sea to feed. That’s where Leopard Seals come back into the picture. A big part of why Leopard Seals endure as apex predators in the southern seas is their diverse repertoire of hunting techniques. In addition to chasing, they will also stalk, flush, and ambush – and a mid-sized penguin jumping back into the sea for its own hunting foray is the perfect situation for an ambush. More than likely, it will be a procession of penguins jumping back into the water to feed. In a colony of more than 100, 000 penguins, these processions are hardly rare. A successful ambush begins with the Leopard Seal lurking just beneath the water’s surface before lunging for its prey’ legs and thrashing it back-and-forth. It’s a quick and violent death for the penguin that requires far less energy for the Leopard Seal than an open water chase.
Chinstrap Penguin
With this broader knowledge of both Leopard Seal and Chinstrap behaviour, it’s much clearer why the seal in our photo may have paid limited attention to the penguin and why the penguin might have felt safe enough to continue its pursuit of krill so close to its primary predator. There may well be even more to the story and further questions are certainly left for us to consider. Had the seal just consumed a larger prey item such as a fur seal pup? Was the penguin an aberrant individual with a higher propensity for risk-taking? Even if definitive answers never materialize, pondering such questions is one of the great joys of observing the behaviours and interactions of animals in the wild.