Many people feel extremely surprised by the horror hunting of coconut crabs – climbing the tree to break the wings of birds, then butcher them.
What do you think crabs eat? You would probably say they eat small animals like worms, snails… But if someone said that there is a species of “giant” crab that eats meat, but is actually bird meat – would you believe it?
If you don’t believe it, visit the remote Chagos archipelago in the Indian Ocean to witness the horrifying scene – crabs slicing birds – which researcher Mark Laidre of Dartmouth College (UK) calls the “terrible end”.
Coconut crab – ruler of the “island of fear”
The species of crab we want to mention here is the coconut crab (Birgus latro) or thief crab – the largest invertebrate crab living on the ground.
As noted, coconut crab can weigh up to 4 kg, its claws can reach up to 1m long. They live alone in underground caves on some islands in the Indian Ocean.
Peeling coconuts to eat becomes too simple with this giant crab
This crab is famous for climbing trees, using its strong claws to crush coconuts to eat. That’s why they are called coconut crabs. Until now, this crab species was thought to only eat carrion, but researcher Mark Laidre discovered the horrifying truth, coconut crabs also know how to go to bird nests to hunt and eat them.
Specifically, in March 2016, Laidre witnessed this giant crab climb to the top of a tree, sneaking close to a red-footed seabird sleeping in a nest on a tree branch near the ground.
The crab then slipped its claws into the nest, broke one of the birds’ wings, and knocked them off the tree. After the first attack, the giant crab slowly crawled to the ground, approached the bird and broke the remaining wing. The bird had its wings broken, lying on its back on the ground trying to resist weakly.
Within 20 minutes, 5 other coconut crabs also pulled together. Perhaps their keen sense of smell prompted them to go where the smell of blood was.
The first attacker drags the still-living bird to a corner and the other crabs rush into each other to fight for prey.
A few hours later, the crabs tore the young bird to pieces and ate most of them. Laidre said: “This scene is really terrible”.
The video helps you visualize the scene of coconut crabs cutting meat and eating birds:
Many people wonder why it only takes 1 claw to break the sweet bird’s wings. According to Shichiro Oka of the Okinawa Churashima Research Center (Japan), coconut crabs easily break the wings of a large bird.
By 2016, he discovered that the claws of coconut crabs when clamped can produce a force of 3,300 newtons – equivalent to a strong bite of a lion or tiger.
Oka said: “Coconut crab’s claws can generate 80-100 times more force than their body mass. This individual crab weighs about 2kg, so it’s not difficult when they break the bird’s wings so quickly and neatly.” .
It is known that this is the first time that researchers have recorded the scene of coconut crabs hunting and killing a vertebrate species.
That shows that they can completely dominate the ecological environment here and make other species – like sea birds – not dare to live here anymore. Because even in the nest on the tall tree branch, the bird also turns into a delicious meal of this giant crab.
Thinking this was just a hypothesis, who knew Laidre had probed and discovered that seabirds had completely disappeared on the island where coconut crabs lived and vice versa.
Now Laidre and colleagues plan to place more video cameras at the entrance to the crab burrow to find out if this predatory behavior is transient or permanent. That is really interesting.
