Pacific Nature Notes

Written for “PIM”

By Charles Barrett, FRZS

Robber Crab Again

WRITING from Kuala Lumpur, Malaya, R.D.L. comments on my notes con cerning the robber crab, a creature that has interested generations of nat uralists. Its habit of climbing trees, as my correspondent points out, was known nearly forty years ago, C. W. Andrews having recorded it in 1909.

A plate in F. W. Christian’s book, “Eastern Pacific Lands,” gives a good portrait of Birgus lateo, with this caption; “A variety of land crab that goes around by night, climbs the palm trees, and with its huge and powerful claws nips off the coconuts from the mother-cluster, and descending, tears off their husks, breaks the shell, and devours the creamy kernel.”

Definite proof that the papaka, as it is called by the natives of Mangareva and Paumotu, breaks unbroken coconuts is still lacking, R.D.L. declares, “and no reputable observer has succeeded in seeing it done.” . . . Consider this statement by Dr. A. Alcock, FRS, who spent four years with the Royal Indian Marine Survey Ship “Investigator”: “Its specific name latro, or robber, is derived from tales of its climbing coconut trees to steal nuts. This seems to be a mistake, though it certainly does eat fallen coconuts when it can get them, tearing away the husk and hammering open one of the eye-holes of the shell with its large nippers, and then extract ing the pulp with the small hind pair of nippers, in the way described by Dar win” (“A Naturalist in Indian Seas.”) I once had a pet robber crab —at least, it was kept in captivity for a week or two. It did not become at all friendly, and was always ready to use its nippers freely when handled.

Cuscus As A Pet

“i'ANE objection to the Phalanger (Cus cus) as a pet,” R.D.L. observes, “is its strictly nocturnal habits. I have kept the Solomon Islands species (P. orien talis) and found it to sleep all day and be very active at night—an undesirable habit in a pet.”

Quite true; but other marsupials, notably the Australian possums, which are noc turnal in their habits, are favoured as pets. Often they become only semi-noc turnal through” being fed, and maybe fondled, in the daytime. Thus, my moun tain or silvery-grey possum was abroad by day as much as he was by night.

I must, however, admit that the cus cuses I have seen in captivity appeared to be disgruntled when disturbed from sleep or drowsiness at any daylight hour.

Still, they were interesting pets, usually docile and have “amusing ways.” My preference is for the brush-tail possum which, by the way, is nearly related to the cuscus. It is said that the latter, though mainly frugiverous, has also car nivorous tastes, and will eat any birds it can capture. The brush-tail possums definitely have this flesh-eating habit.

I have known a tame “silver-grey” to devour with relish a freshly-killed young rabbit.

The “Ghost Bat”

DESCRIBING a giant bat, seen by him in Papua, George R. (in New Ireland when he wrote to me) asks whether the ghost bat (Macroderma gigas) has ever been recorded from Papua-New Guinea.

So far as I know, this great-eared bat, related to the false vampire of India, has never been found outside Australia. Ap parently a rare form, macroderma, whose ghostly, bleached appearance is caused by the almost white membranes and pure white hair on the under-surface of the body, occurs only in South and Central Australia. Very few specimens have been

collected. However, numerous mummi fied “ghost bats” have been found in shallow caves in districts where the living Macroderma has not been seen for many years. I know one Queensland haunt of the species—Olsen’s Caves; but only a few “ghosts” were seen there on my last visit to the Caves, in 1945.

Communications from Nature students in the Pacific Islands are welcomed by our contributor—Mr.

Charles Barrett, “Maralena,” Mays bury Avenue, Elstemwick S 4, Victoria.

The creature described by George R., was undoubtedly one of the big fruit-bats.

“Some months ago, I was hunting after a deer or a pig on Vaigen Swamp, some ten miles from Port Moresby, and there, in broad daylight, I saw a huge ‘flying fox.’ Well over two feet in length, it had pale ‘ghostly’ wings, with a span, so far as I could judge, of much more than six feet. I could estimate it, too, having shot specimens of Gould’s mantled bats which had a wing-span of from five feet to five feet nine inches. I did not fire at my “ghost.” I carried a heavy (.375) rifle, and would have blown it to bits; more over, I had no means of preserving the body even had the specimen been col lected. The only species I could think of, which it might be, was Macroderma gigas.”

None of the scores of flying-foxes (museum specimens) I have seen measured more than five feet across the wings; and those with this impressive wing-span were kalongs, from Java, which, I believe, are the largest of all living bats. The grey-headed fruit-bat of Australia has a wing-spread of up to nearly four feet.

Flying-foxes are widespread in the Western Pacific islands —more widely than any other fruit-eating bats. Four or five species inhabit Australia. The curious tube-nosed fruit-bats range from Celebes and Timor to Queensland and the Solomons. Their descriptive name is not fanciful, for these ugly creatures actually have projecting tube-nostrils. The long tongued bats also deserve their name, the tongue in all species of Macroglossus being elongated and as protusable as that of a honey-mouse.

The mother bat, as is well known, carries her baby with her on long-dis tance flights to and from feeding-grounds, as well as roundabout the “camp;” the little naked creature clinging tightly to the front of her body. Twins are not “fashionable” among bats, but some species are known to produce them oc casionally: and there are even records of quartettes.

An American species became famous among naturalists specialising in bats, when it was proved by actual specimens —mother and infants—that quartettes were produced by Lasiurus borealis. Later, evi dence was forthcoming that, with this species, such big families were usual; and that the four young ones were habitually carried about by the female, clinging to her body.

I would like to hear from any reader of these notes who has visited a flying fox “camp,” and estimated the size of the population. The biggest “camp” I have seen was at Byfield, Central Queensland, where perhaps nearly 250,000 bats were at home in the daytime; at night they were miles away at their feeding-ground.

There may be even more populous flying fox communities in some Pacific lands.