Researchers captured the moment a former vegetarian broke through the hierarchies to eat meat – and what made it even more “terrible” was that he was a tortoiseshell.
Scientists have captured on video the moment a giant Seychelles tortoise – thought to be a herbivorous species – attacked and ate a tern baby, which they say was the first intentional attack on any wild turtle species. is document. .
“This is completely unexpected behavior and has never been seen before in wild turtles,” Justin Gerlach, director of the study at Peterhouse, Cambridge, and affiliated researcher at the University of Cambridge’s Museum of Zoology, said in a statement on Monday. )
“The giant turtle chased the baby tern with a log, eventually killing and eating the baby tern,” Gerlach, who led the study, published Monday. Revista Current Biology.
“It was a very slow encounter, with the tortoise moving at its usual slow pace—the whole conversation lasted seven minutes and was pretty terrifying.”
Anna Zora, conservation manager for Fregate Island and co-author of the study, captured the moment, which happened in July 2020.
“When I saw the turtle moving strangely, I sat down and watched, and when I realized what it was doing, I started filming,” Zora said in the statement.
Gerlach says CNN That the way the tortoise moved towards the hatchling suggested that it was “seasoned”.
“He’s moving very deliberately – he’s not just going astray, he’s watching this turn and he’s walking in exactly that direction, clearly intending to do something. Doing it with intent. He knows what he is doing, he has done it before.”
Although turtles are considered herbivores, they have been observed eating carrion in a “timely manner” as well as snail bones and shells for calcium.
“It is quite common for vegetarians to essentially eat some dead animals as a source of free protein. But this is their first video evidence that there has been intentional killing for eating,” he said.
Still, the team can’t say for sure how common this behavior is among turtles and plans to study them further.
Giant tortoises are the largest herbivores in the Galapagos and Seychelles Islands and eat up to 11% of vegetation, the researchers said. Gerlach said turtle behavior is unlikely to have a significant impact on tern populations.
Experts said the new hunting behavior was caused by the “unusual” combination of a tern colony with nesting trees and the giant tortoise population on the Seychelles’ Fregate Island, which is home to about 3,000 turtles.
This isn’t the first time unusual lethal attacks have been observed between animal species in the wild – chimpanzees were first seen killing gorillas in the wild in 2019.
“It’s probably not unusual for animals to surprise our expectations by eating things that are unexpected, which may be unique,” Gerlach explained.
“We should try to avoid making too many assumptions about what animals will do or what they’re doing. And that really shows the value of observation. By observing and recording what animals are doing, you can get a complete picture of what animals are doing.” We can find kind of unexpected things, things we might not otherwise find – it must be by chance,” he said.
(Translated text. read original in English.)