In the case of the giant tortoise, its hunting behavior appears to be a collision of ecological quirks. Terns nest in the trees of Frégate Island, which is both tropical and heavily forested. But the ground is home to its other predators, like lizards and crabs. This means that the forest floor is lava for any chick who is not yet able to get away from danger. The instinct of the bird tells it to perch on a tree, at all costs. That’s why in the video, you can see her backing up along the branch as the turtle approaches, instead of just jumping into the leaf litter and escaping. “You have a source of meat, but it’s also something that a turtle can’t escape – and almost anything can run faster than a turtle, ”says Gerlach. “Because it’s a nest of trees, it wants to stay off the ground, because the ground is where all the danger is. ”
What appears to be an unfair fight is actually quite dangerous for the turtle. He has a thick shell to protect his body, but his eyes are exposed. And the chick was pecking like his life depended on it, because he does a lot. “They don’t like things to come close to their eyes,” says Gerlach. “They’re pretty careful about it – that’s the only vulnerable part of them. So this turtle is putting itself in danger. Losing one eye and surviving becomes all the more difficult: lose two and you will die soon.
So it is not an easy meal, nor a simple opportunism. The turtle hunts like she knows what she is doing, Gerlach said, supporting the chick until it reaches the edge of the log and the bird’s instinct tells her not to go any further.
But is a turtle’s digestive system even equipped to handle meat? “No one watched this at all,” Gerlach says. “They don’t eat meat, why would you want to search?” ”
Nonetheless, since a certain degree of scavenging is common in herbivores, he believes they must be able to extract amino acids and minerals from meat. After all, he says, animal protein is relatively easy to digest. “Digesting plant matter is a difficult evolutionary task to do,” he says, because plants are made of hard materials like cellulose.
What is a tragedy for a chick is actually a promising sign for the birds of Frigate Island as a whole, says Gregory Pauly, curator of herpetology at the Natural History Museum of Los Angeles County, who was not involved in the new article. This means the birds are back and the turtles are more than happy to enjoy it. “The number of turtles and birds in this region has declined due to habitat destruction, the introduction of species such as rats and large grazing mammals, and exploitation by humans. He wrote in an email to WIRED. “Thus, the ability to observe even predatory interactions like the one described was not even available until recently, as the bird population has rebounded through habitat restoration efforts.”
How many turtles can hunt like this? How often do they do it? “We really don’t know if this is just an interesting sighting, or if it is actually a really important development in the island’s turtle ecology and also in the ecology. of the island, ”says Gerlach. “So we’re at the ‘Lots of Questions’ stage. “
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