Surprising Scientists: Giant Tortoise Devours Baby Bird

In a first, researchers in the Seychelles document the large reptile stalking and devouring a chick

The giant tortoise clumsily stalked and ate a lesser noddy tern chick, raising questions about their herbivorous diet.

A recent event has scientists wondering if giant tortoises are as herbivorous as previously thought. For the first time, researchers in the Seychelles documented a giant tortoise stalking and eating a young tern chick. The video, published yesterday in Current Biology, is the first time an event like this has been captured on camera.

“It’s totally surprising and rather horrifying,” study author Justin Gerlach, an ecologist at Peterhouse, Cambridge in England, tells Jason Bittel for the New York Times. “The tortoise is deliberately pursuing this bird and kills it, and then eats it. So yeah, it’s hunting.”

Before scientists on Frégate Island in the Seychelles witnessed the event in July 2020, giant tortoises were thought to be devoted herbivores. They can live for more than 150 years and grow to be over 500 pounds, sustained by a diet of grasses and woody plants in the Seychelles and Galápagos Islands. Though the reptiles have been known to occasionally munch non-veggie items like discarded shells and leftover bones, researchers didn’t suspect to see one gulp down a live bird.

“No one’s looked for it, because why would you? Tortoises don’t hunt,” Gerlach says to the New York Times. “You’re not going to just waste your time looking for a hunting tortoise.”

In the video recorded by Gerlach’s co-author Anna Zora, a female giant tortoise creeps toward a lesser noddy tern chick perched on a log. When the tortoise is within striking distance, the bird makes an attempt to deter her by flapping its wings and pecking her face. She lunges forward and snaps down on the chick’s head before swallowing it whole a few moments later.

“It really shows that we can still find really unexpected things from simple observation—not all scientific discovery is about expensive equipment and fancy laboratories,” says Gerlach to Gizmodo’s Issac Schultz.