Scientists captured the moment on video when a giant Seychelles turtle, previously thought to be a vegetarian, attacked and ate a tern chick in what they say is the first deliberate hunting document on any turtle species. wild.
“This is totally unexpected behavior and has never been seen before in wild turtles,” Justin Gerlach, director of studies at Peterhouse, Cambridge and an affiliate researcher at the University of Cambridge’s Museum of Zoology, said on Monday.
“It was a very slow encounter, with the turtle moving at its normal, slow pace: the whole interaction took seven minutes and was pretty awful.”
Anna Zora, head of conservation at Frégate Island and co-author of the study, captured the ordeal, which took place in July 2020.
“When I saw the turtle move in a strange way I sat down and looked, and when I realized what I was doing I started filming,” Zora said in the statement.
Gerlach told CNN that the way the turtle moved toward the chick suggested she was “experienced.”
“She moves very deliberately: not only does she walk, but she looks at this sternum and walks straight towards it, with the clear intention of doing something. This suggests to me that she does it with intent. She knows what she’s doing, she’s done it. before, ”he said.
Although turtles are believed to be vegetarians, they have been seen as “opportunists” eating carrion, as well as bones and snail shells for calcium.
“It’s quite common for herbivores to eat some dead animals as a source of free protein, basically. But that’s the first video evidence they deliberately killed for food,” he said.
However, the team cannot say for sure how common this behavior is among turtles and plans to study them further.
Giant turtles are the largest herbivores in the Galapagos and Seychelles islands and eat up to 11 percent of their vegetation, the researchers said. Gerlach added that the turtle’s behavior is unlikely to significantly affect scrap metal populations.
Experts said the new hunting behavior was caused by the “unusual” combination of a colony of terns nesting trees and a population of giant turtles living on the island of Frégate in the Seychelles, where about 3,000 turtles live.
“It’s probably not uncommon for animals to surprise our expectations by eating unexpected things that can only be unique,” Gerlach explained.
“We have to try to avoid too many assumptions about what animals will do or what they do. And it really shows the value of observation. Just by looking at and recording what animals do you can find really totally unexpected things, things we haven’t been able to discover. deliberately: it must be by chance, ”he said.