WAYS OF THE WILD.

Auckland Star, Volume LXVIII, Issue 234, 2 October 1937, Page 1 (Supplement)

WAYS OF THE WILD.

TORTOISES AND TURTLES. DISTRIBUTION AND SURVIVAL. (By A. W. B. POWELL) The death last week at the Auckland Zoological Park of a giant tortoise provides the museum with a valuable specimen of the largest living species of this interesting group of reptiles. Giant tortoises are found at the Galapagos Islands, and originally occurred on certain islands of the South Indian Ocean, notably Aldabra Islands, northwest of Madagascar, Reunion, Mauritius, Rodriguez, the Amirantes and the Seychelles. Our specimen was brought from the latter locality by the Orangeinoor in January last, but it is not a native of the Seychelles.

The Aldabra Islands were the original home of this, the elephant tortoise, but it was exterminated there early last century, the species fortunately surviving in the Seychelles, where it was previously introduced by the planters and kept in semi-domestication. By a fortunate chance, this early practice of taking tortoises from one island and depositing them jii another, more accessible, resulted in several escapes from utter extinction. A striking example is in the case of Porter's black tortoise, a native of the Galapagos. These islands, by the way, owe their name to "Galapago," one of the Spanish names for a tortoise. In 1813 a Captain Porter took a large number of Galapagos tortoises and distributed them among the chiefs of Fiji. Fortunately, many of these tortoises escaped into the interior, and with the extinction of tne species in its original home we still have the opportunity of studying it in the wilds of the Fijian Group. ■ Slaughtered for Food. At the beginning of last century the islands of the South Indian Ocean were heavily stocked with giant tortoises, but the early voyagers and colonists at Mauritius soon hopelessly depleted jiumbers by using them as food. Within the short space of 18 months 30.000 were transported from Rodriguez to Mauritius for that purpose. Giant tortoises were a boon to the early voyagers, for they could be carried in the hold of a ship without food for months' and were slaughtered as required, each "tortoise yielding, according to size, from 80 to 300 pounds of excellent and wholesome meat. The French traveller Leguat tells

us that in Rodriguez the tortoises covered the ground so tliickly in places that a man might walk a hundred paces or more by stepping from the back of one to that of another.

Although • the Auckland specimen survived but eight months, this is in accord with other attempts to introduce the species into temperate lands. Even with carefully regulated heating devices these tortoises seldom live long outside the tropics. The size of these tortoises is amazing, for they have been known to attain a length of four feet and a weight of 870 pounds. The carapace, or shell, of the Auckland specimen is 30£ inches long and 20J inches wide and the animal 6tood 18 inches from the ground. The Auckland specimen is estimated to be 35 to 40 years old. A huge example in the British Museum of Natural History, however, was known to have been more than 80 years of age when it died, and it weighed 870 pounds.

Force of circumstances or idiosyncrasies in the choice of food among the tortoises have in the course of countless generations led to changed habits and with them the spreading of s;>ecie» far and wide over the earth's surface.

Some eventually took to fresh water and originated the race of pond tortoises. From inland ponds and streams it was but natural that some should reach the estuaries and finallv the open sea. In the train of this migration from the land to the water followed profound changes in their structure, more especially in regard to their forelinrbs, and thus originated the turtles. The stumpy feet of the land tortoise gave place to the webbed feet of the pond and river tortoises and finally to the "flippers" of the marine types.

Occasional Visitors. There are no Xew Zealand native tortoises, but turtles occasionally reach our shores, especially the green turtle, ( helone mydas. In the Auckland Museum collection there is a specimen of this turtle which was harpooned near Manukau Heads by a party of Maoris. It is a young example, the total length being 2ft Oin. The late Mr. T. F. Cheeseman recorded a larger one with the carapace, or shell, alone 3t"t in length, which was caught in (ireat Exhibition Bay, to the south of Parengarenga Harbour. Xlris widely distributed green turtle is Fiie source of the far-famed turtle soup. The species is easily recognised by its smooth back, the shields being butting, not overlapping like shingles or roof tiles, as in other species. Also the beak is short and devoid of the hook at the tip. The food of this species consists of seaweeds, upon which it grazes, rising occasionally to the surface to breathe.

A second species of turtle is known from New Zealand waters as an occasional visitor, tlie leathery turtle. Dermochelys coriacea. two occurrences having been recorded by the late Mr. T. F. I'heeseman. one a little over Oft in length and the other *ver 7ft. The first was obtained off Cape Brett in May, 1892, and/the second two years Inter from between the Bay of Islands and Mangonui. Both were taken by Captain Subrit/.ky. of the schooner Medora.

Largest of All Living Turtles. 1 lie leathery turtle differs from all other turtles in the body not being covered with hard plates, but with a thick leathery skin, winch is quite smooth when the animal is adult, with the exception of seven conspicuous ridges, which run lengthwise along the whole of the lwck. It is the largest of all living turtles, examples over 9ft in length and weighing as much as 18001b having been captured.

The proper home of the leathery turtle is in the warmer parts of the Atlantic, Indian and Pacific Oceans. Its enormous paddles give it great swimming powers, and it ventures far out to sea and sometimes strays to very distant localities. Specimens have been stranded on the coasts of France and Holland, and several have reached England. In the temperate parts of the Southern Hemishere it had only once before been noticed—in 18i'r2. when a half-grown specimen was captured at Portland, on the coast of Victoria. Prolmbly both that and the New Zealand occurrences had wandered from the tropical Pacific Islands, where they a re occasionally seen, but never in large numbews.