Watch: New video reveals “horrifying and amazing” tortoise behavior

However, as a new study of a tortoise attacking a tern chick proves, you may want to add methodical hunter to that list.

A warning here: This story is not for the faint of heart.

Some tortoises will even munch on bones and carrion they come across in the wild.

But in a video shot by Frégate Island deputy conservation manager Anna Zora, a tortoise is seen deliberately hunting, killing, and eating a tern chick.

In the video, the tortoise walks slowly toward the tern chick — a type of seabird — cornering it on the edge of a log, before biting its head and later swallowing the bird whole.

It’s the first time this kind of hunting behavior by a tortoise has been captured on video.

According to the research team, the tortoise’s open jaws and retracted tongue are signs of deliberate aggression rather than normal feeding.

Frégate Island’s unique ecology may also play a significant role in the story of the tern and the tortoise.

Conservation efforts have led to high bird and tortoise populations, bringing the animals in closer contact with each other than would be possible in other places.

When tern chicks fall out of nests, they instinctually avoid the ground. The tortoise trapping the chick on the log may indicate that it’s not the first tern it’s gobbled up.

One video doesn’t prove whether this hunting behavior is widespread or newly emerging, but other tortoises have been observed snacking on birds on Frégate Island.