Eagles that eat lion cubs

Martial eagle with a wingspan of nearly 2 meters targets lion cubs on the African grasslands despite the risk of being discovered and attacked by the mother lion.

In December 2012, guides in Kenya's Maasai Mara National Reserve witnessed a series of kills targeting one of the savannah's top predators. An adult martial eagle stalked a pride of lions for weeks, waiting for the right moment to swoop down and kill a total of three cubs. 'The eagle was really targeting the lions ,' said R. Stratton Hatfield, a doctoral student at Wageningen University in the Netherlands.

A martial eagle catches a three-week-old lion cub in the Mara North game reserve in Kenya. (Photo: Jes Lefcourt).

While lions may dominate their territories, this and many similar cases show that African lions ( Panthera leo ) are not always at the top of the food chain. In fact, martial eagles ( Polemaetus bellicosus ) are more likely to prey on lion cubs when given the opportunity, according to research by Hatfield and colleagues published in the journal Ecology and Evolution.

The wingspan of the martial eagle can exceed 1.8 meters. Adult females weigh more than 4.5 kg, while males typically weigh around 3.2 kg. Although similar in size and habitat to the golden eagle, martial eagles typically kill larger prey. They swoop down and sink their sharp talons into the spine at the back of the skull of their prey, sometimes taking down impalas or gazelles that weigh more than they do.

It was only recently that Hatfield's team discovered that martial eagles prey on other predators. The team collected information on seven cases, including a 2012 incident in which martial eagles hunted juvenile lions, resulting in the deaths of seven cubs and one near-death. Hatfield suspects that most of the cases involved adult female eagles, although two cases involved juvenile eagles. The earliest case occurred in 2008, when a photographer photographed an eagle eating a newly killed lion cub, while the most recent was in 2023, when a safari guide saw a juvenile eagle kill a lion too large to carry.

Despite their aerial hunting skills, martial eagles are often at risk of retaliation. In one failed attempt, a martial eagle swooped down to snatch a six-week-old lion cub from its mother. The lioness sensed the approaching danger and pounced on the eagle. The eagle dodged the attack and failed to catch the cub. Hatfield speculates that it did not see the lioness.

Amy Dikeman, a conservation biologist at the University of Oxford in the UK, wouldn't be surprised if eagles continued to target lion cubs if the tactic worked. Dikeman is the director of Lion Landscapes, a nonprofit focused on human-wildlife coexistence in Kenya and Tanzania. She said Hatfield and her colleagues' conclusions were reasonable. Eagles, she said, are just as much a threat to lions as hyenas or male lions from rival prides. Eagles are not a conservation threat to big cats. Martial eagles are not picky about their prey. Some even take the cubs of cheetahs and leopards. The threat often goes both ways. Lions may also prey on adult eagles or nestlings.

Martial eagles are listed as endangered by the International Union for Conservation of Nature. Like other large birds of prey in Africa, they suffer from habitat loss, poaching, electrocution, and persecution.