A researcher who worked on the Chagos Islands in the Indian Ocean in 2016 says he witnessed a large coconut crab attack a sleeping seabird, which then became dinner.
Chasing its prey back down onto the floor, the crab finished the poor bird off by breaking its other wing.
He told the New Scientist: "At that point, when both its wings were broken and it was on the ground, it couldn't go anywhere". This brutal crab-bird dissection probably isn't a one-off, either: According to Laidre, the birds tend to stay away from certain crab-infested islands, ostensibly to keep from being massacred.
This predator crab is filmed pinning down the bird with its huge claw.
Once the bird was paralysed on the ground, other grabs arrived to help dismember the bird in scenes the veteran scientist described as "pretty gruesome".
Mr Laidre, of Dartmouth College in New Hampshire, plans to set up cameras by the crabs' burrows to explore their predatory habits.
Coconut crabs are the largest land-living arthropods in the world and an adult can measure three feet across with legs extended and weigh up to nine pounds.
Previous year research by Shin-ichiro in Japan found the crabs' claws can pinch with a force of 3,500 newtons, which is comparable to a lion's bite.
In addition to coconuts (which aren't a major part of their diet), these omnivorous creatures are known to eat carrion.
"The crab in the video seems to be about two kilograms, so it would be able to easily break the bird's bones", he added.