This thievish crab seemed marked by his star—doubtless of the Cancer constellation—to play a deceptive part in the crustacean world, for not only had he practically abandoned the water as his element, learned to climb trees, and to eat food utterly foreign to his natural appetite, but he had a habit of hiding his tail when the rest of his body was in full view. He would stick it in any convenient hole, under a log, or even in the cocoanut-shell he had emptied. He was over-conscious and seemingly ashamed of it, like an awkward man of his hands at a wedding.
The kaveu’s descent from the hermit-crab family might explain his tail-concealment custom, for the hermit concealed his entire body in a borrowed shell, and so, perhaps, the robber-baron was but showing an atavistic remnant of the disguise instinct. The whole crab tribe seemed tainted with this fear of being merely themselves. Many of them picked up a piece of seaweed and stuck in on their projecting curved bristles, and let it grow as a kind of permanent bonnet. Others took pieces of live sponge, and fastened them to hooks on their backs. One clever chap stitched seaweed threads together to form a tube, and then crawled into it. And one masonic crab mixed a sandy cement and plastered its back with it until it looked like the floor of its pond.
These specious masqueraders selected colors, too, to suit their background, and the seaweed or sponge must match the environment or be rejected. Older and hardened backsliders invited oysters and other mollusks and worms that live in limestone pipes to dwell on their shells, and move about with them. I was convinced that these low-down-in-the-scale beings knew more about their environment, and practised “safety first” more assiduously, than did man himself. The biggest robber-crab in the Takaroa groves could not have got a humble hermit brother to volunteer to go to war against a crab colony, or risk his life to glorify the crab state.
Photo by Dr. Theodore P. Cleveland
Robber-crab ascending tree at night. One of the few photographs taken of
the marauder in action
In carrying a cocoanut, the robber crab held it under some of its walking legs, and retired, raised high on the tips of its other members a foot from the ground. Its body measured two feet long by eighteen inches wide. It did not use its claws in ascending the tree, but clung with the sharp points of its legs; and I saw it go up steep rocks upon these. The remarkable strength of this mollusk was proved when one was placed in an ordinary tin cracker-box, which it could not take hold of, and a few hours later had twisted off the lid. Nohea said that they were not easy to trap, and that more than once a Paumotuan, who had climbed a tree in the night to procure nuts, to his great horror had had his hair seized by a crab. He said that usually they bit off from six to ten nuts upon each ascent of a palm.
Photo from Dr. Theodore P. Cleveland
Where the Bounty was beached and burned
“The kaveu likes to eat the young turtles when they are hatched and making their first journey to the water,” Nohea informed me. “The crab, knowing where the eggs are buried, watches them as they mature in the sand.”
I told Nohea of the crabs I had seen in Japanese waters, some stretching seven or eight feet, and another which bore a human face upon its back. To see one of the latter crawling upon the sand was to see what apparently was a human mask moving across the beach. The Japanese said that these crabs were never known until after a fleet of pirates had been destroyed, and the leading villains beheaded upon the sea-shore.