Giant tortoises were long believed to be herbivores, but a newly released video features graphic evidence that's not true. The tortoises, who live only in the Seychelles and the Galápagos Islands, apparently even hunt, say the researchers who recorded one such animal in the Seychelles stalking, attacking, and ultimately eating a baby bird in July of last year. It's the first time such an incident has been caught on video, the New York Times reports. Seabird chicks such as the tern seen in the video are helpless if they fall out of their nests, and there had been rumors tortoises may have eaten them, but this is proof.
The video also indicates it has happened before, as the tortoise eats the bird without extending its tongue to draw the food in, as it normally would. This seems to show the animal is aware the bird presents a danger that grass or fruit would not, scientists say. The Guardian explains that while giant tortoises were previously known to eat carrion from dead birds, goats, or other tortoises, that was thought to be only opportunistic feeding; they also eat bones and snail shells for calcium. Island systems often lack the mineral, which is needed to build eggshells, and scientists say this may be a way giant tortoises have evolved to make sure their species will continue. (Read more giant tortoise stories.)