Black Mouse
In an incredibly unlikely encounter, a giant “vegetarian” turtle was filmed attacking a seabird – including biting its head and consuming the rest.
The event, involving the large reptile and a tern seabird living on Frigate Island in the Seychelles, was “completely unexpected”, according to researchers from the University of Cambridge Museum of Zoology, who attended the meeting. .
It was the first time that a turtle had been captured deliberately hunting prey in the wild.
Researchers believe this behavior was prompted by the large colony of tree-nesting nodule terns and the 3,000 turtles living closely on the island.
The chick likely fell from the tree above, landing on a log where the giant tortoise slowly approached, and during a seven minute encounter killed and fed on the bird.
In an incredibly unlikely encounter, a giant “vegetarian” turtle was filmed attacking a seabird – including biting its head and consuming the rest.
The ground beneath the colony is littered with birds and chicks that have fallen from their nests.
The “hunting camera” video shows the bird standing as the turtle approaches, suggesting that this type of interaction occurs frequently.
In most places, potential prey are too fast or agile to be captured by giant tortoises.
On the Galapagos and Seychelles Islands, giant tortoises are the largest herbivores and eat up to 11% of the vegetation.
They also play an important role in seed dispersal, vegetation breakdown and rock erosion.
This is what Anna Zora, responsible for the conservation of Frégate Island, claims, who filmed the hunting of the bird.
She said: “When I saw the turtle move in a weird way, I sat down and watched, and when I realized what she was doing, I started filming.”
The encounter was probably possible due to the recent extensive habitat restoration on the island which has allowed the tern colony to grow so dramatically.
“I couldn’t believe what I was seeing,” says study author Dr Justin Gerlach, director of biology studies at Peterhouse College, University of Cambridge.
The scene was shot in the forests of Frégate Island in Seychelles, an archipelago off the coast of East Africa.
“It was both horrible and incredible,” according to the researcher.
The event, involving the large reptile and a tern seabird, living on the island of Frigate in the Seychelles, was “completely unexpected”, according to researchers at the Cambridge University Museum of Zoology, who attended the meeting.
On the Galapagos and Seychelles Islands, giant tortoises are the largest herbivores and eat up to 11% of the vegetation
In the video, an adult female turtle heads straight for her target at a normal pace: a tern chick stranded on a log.
“He was looking directly at the tern and walking deliberately towards it. It was very, very strange and totally different from the normal behavior of a turtle, ”said Gerlach.
Slow and steady, the turtle is getting closer. As it approaches the bite distance, it reaches out its hand with its mouth open.
The chick tries to defend itself by pecking at the turtle, but its efforts are in vain.
It was the first time that a turtle had been captured deliberately hunting prey in the wild. Previously, they had been seen feeding on bones and snail shells for calcium
Once the chick reaches the end of the log with nowhere to go, the turtle crushes its jaws directly on the chick’s head.
The soft chick falls off the log. The turtle comes down and swallows it whole. The whole process takes seven minutes.
The island’s giant tortoises were seen consuming snail bones and shells, but it was speculated that they weren’t hunted, and this was done to boost calcium levels.
“It has always been impossible to tell if the turtle directly killed the animal, or if it had just sat on one of them and found it conveniently run over,” says Gerlach. “Why refuse a little free protein? ”
Researchers believe this behavior was caused by the large colony of tree-nesting nodule terns and the 3,000 turtles living close together on the island.
The chick likely fell from the tree above, landing on a log where the giant tortoise slowly approached, and during a seven minute encounter killed and fed the bird
He said in the video that it looked like the turtle had captured chicks on logs before, as if this was something that happened on a regular basis.
When the chicks fall, their instinct is to avoid the ground at all costs, “which is probably why the chick stayed on the log even as the turtle got closer,” Gerlach said.
He added: “It seemed to me that this individual had already hunted successfully; he seemed to know what he was doing.
Although this turtle appears to be an experienced hunter, questions remain about how many turtles hunt, how often they do so, how much food they get from it, and if this happens in other places as well.
“Could we see a population of turtles developing a new type of behavior with evolutionary implications, or is that just an interesting observation for now? Gerlach reflects.
He suspects that conservation efforts on Frigate Island may be behind the emergence of this unusual behavior.
Although seabird and turtle populations have been in decline for the past few hundred years, efforts on the island have revived the population of both to create a very unique combination of bird and sea populations. turtles.
Gerlach said conservation efforts “are recreating conditions for natural behaviors that people have not seen in hundreds of years.”
“There are a lot of stories of turtles eating snail shells so that calcium could make their own skeletons, but I don’t see why they couldn’t consistently eat snails, too,” he said.
The researcher said that despite all the unknowns, the effort the turtle makes to eat a tern is considerable, compared to munching on plants, which suggests that seabirds are a delicacy for reptiles.
The results were published in the journal Current Biology.