Snaring New Zealand Wallabies

Auckland Star, Volume LXXI, Issue 70, 23 March 1940, Page 2 (Supplement)

Snaring New Zealand Wallabies

RECENTLY as a member of an Auckland Museum field expedition I had the opportunity of taking part in an investigation into the present status of the marsupial introductions originally made at Kawau Island by Sir George Grey over 70 years ago. These introductions took the form of four species of wallabies and the common opossum. It was found that all the species have done well in their new home, so well in fact that in the eyes of the settlers the presence of these animals is no longer appreciated. Certainly they are attractive creatures, but their toll of vegetation, grass and particularly fruit crops is only too evident. Three of the wallabies are generally distributed, but the fourth, the brushtailed rock wallaby, is locally distributed only in several small colonies on the somewhat inaccessible eastern side of the island. This is the most wary and agile of all the species, and in consequence, there is little local knowledge of its habits except that it, is nocturnal and that on being disturbed it can scale dill's or reach "the lops of poliutukawa trees with lightning speed. Astonishing Agility The descrJption'is thoroughly in accord with this animal's habits in its original home which is the ranges of eastern Australia to as far north as Eockhampton. An Australian authority states that "the agility of the rock-wallaby in its natural haunts is positively astonishing. Xo living creature could be more accurate in its judgment, and no other animal would dare to perform such rapid 'stunts' without bringing the fore-limbs ■ occasionally into action. When hotly pursued, the rock-wallaby will make for a tree at top speed, and without hesitation, spring as high as possible up the. ; trunk, then finally gain a fork or large • limb and sit tight, perched at right angles to tho bough, gripping only with the padded soles of the feet." The three other Kawau wallabies are all ground forms, showing no particular agility as far as jumping is concerned; in fact, they will make long detours in : order to find a break in a fence rather . than jump. This habit makes trapping : a fairly simple and efficient procedure. < As a preliminary to trapping, brush is . piled lengthwise against the fences, leaving here and there gaps of about a foot : in width. Soon tho wallabies get used i '14—,—: _—

to using these gaps in their nocturnal wanderings, and once they have formed the habit the time is ripe for setting the traps. These are in the form of a long, springy sapling, set at an angle in the ground; a cord fastened, at the end has a toggle about a foot down and then a noose. An ingenious platform of sticks held down by two forked sticks and set by using the toggle as shown in the sketch, completes the trap, tho noose

ByA. W. B. Powell

lying open on the platform. As soon as the wallaby attempts to cross the trap, tlie platform gives way, the. toggle is freed and the sapling springs upward, lnssooing the animal with the noose. The species so caught arc usually the Duma, wallaby, locally called the small brown and the black striped wallaby, known also as the silver grey. The larger black tailed wallaby is usually 100 strong to remain trapped—he is a handsome boast, standing about three feet in height, greyish brown and with a thick, conspicuously black tai. His native home is South-eastern Australia, as also is the black striped species. The Dania wallaby, however, is from Southwest Australia, and the islands off that coast. Colouring Changes As I rcjnarked in a previous article, seventy years of acclimatisation in New Zealand has wrought changes in these animals. In 1930, Jlr. A. S. Le Soucf wrote an interesting paper based upon a comparison between Kawau and Australian skins. He found that in each case a different coloration of the coat had resulted from the fur becoming longer and softer, with the overlay of black hairs more pronounced. In the case of the black-tailed wallaby lie found that the fur on the buttocks was a much brighter foxy red than in Australian examples. Xot" only has the Kawau habitat wrought changes in these introduced Australian mammals, but the native fauna and flora has been modified also. Just what the position may be, say, in another seventy years, it is diflicult to forecast. Research into the effects of acclimatisation in N'ew Zealand is urgently required, and Kawau Island should offer a promising field to any student of animal ecology. " <~