Why did the lion swim across crocodile-infested waters? It was his only remaining option to find a mate, according to a study in Ecology and Evolution.

That report was based on observations of lion behaviors driven by skewed sex ratios in a Uganda national park. The swim — across a channel over half a mile wide — may be the longest recorded by a lion.

The swim’s length, as well as its obstacles (the waters contained plenty of hippos as well as crocs) shows the lengths that lions will go to find a mate, when the pickings are slim.

“Skewed sex ratios mean males have to search harder and take bigger risks to find females, as evidenced by swimming,” says the study’s co-author Alexander Braczkowski, from Griffith University in Australia.

Limited Lion Mating Options

The lead lion, Jacob, was running out of options. He had problems protecting his pride. He had lost several fights with males for the few female lions on one side of the channel. And the risks he took were even bigger because Jacob was physically compromised. Between 2019, he had been gored by a buffalo, snared by a poacher, and severed a leg in a steel trap. He had also lost much of his family to poisoning.

Jacob and his swimming partner, brother Tibu, must have almost certainly heard female lion calls from across the channel. And they were probably also aware of the dangers the journey presented. Although lions dominate the land, they are vulnerable when swimming.

“They fare pretty badly in water,” says Braczkowski. “They can’t really do much in the water compared to hippos and crocs, which feel the most comfortable in the water!”

Braczkowski was concerned when watching the swim live, via drone camera. He remembers asking his camera operator Luke Ochse to bring the drone in, or risk losing it in the water. But he was more concerned about Jacob and Tibu than the drone.

“I was scared that a crocodile might grab the brothers, but they seem to be stronger swimmers than we all thought,” says Braczkowski.

Read More: Male Lions Fend Off Other Males and Hyenas When Their Pride Has Cubs

Big Cat Tenacity

Although Braczkowski was primarily investigating the effect of lion behavior when their population was dominated by males, he couldn’t help but be impressed by Jacob’s tenacity, with whom he had been following for years.

Braczkowski first began filming Jacob in 2017 for a National Geographic and Disney Plus documentary called “Tree Climbing Lions.” Braczkowski has been running a long-term study of African lions and other predators in Queen Elizabeth and several other Ugandan National Parks.

He marveled after Jacob survived one trial after another. “Maybe it’s his genes, maybe it’s his spirit — I do think he is the most resilient lion in Africa,” Braczkowski says.

Lions in that part of Africa need all the resilience they can get. Increasing human population pressure and poaching have led to the lion population almost halving in five years.

Read More: The Fast, Furious, and Brutally Short Life of an African Male Lion

Article Sources

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Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.