THE INTRODUCED ANIMALS

New Zealand Listener, Volume 15, Issue 382, 18 October 1946, Page 30

THE INTRODUCED ANIMALS

Ths article was to have concluded H. SORENSEN‘S account of wild life in the Campbell and Auckland islands, but he has responded to an appeal for just one more. This will appear in our next issue and will be ! "positively the last appearance" of a most popular feature-at least, until after the author mokes another trip to the Deep South.

duced to the sub-antarctic islands now form part of the wild life of the region, it seems not inappropriate to include them in this series. Some were introduced with the high ideal of providing food for castaways; some were left when attempts at. colonisation~ failed;* others arrived by accident. Those that survived have seriously disturbed the balance. of nature on the southern islands and it is to be hoped that steps can be taken very soon to have them exterminated, letting the islands revert to their natural state before it is too late. The use of the "Great Circle route" in the days of sail accounts for the large number of wrecks on the Auckland Islands for these were almost squarely on the route ships had to take. The rough weather and poor visibility so often encountered in those latitudes often prevented accurate bearings being taken and a ship only a little off her course could come to grief. Had the Derry Castle for instance, been only 100 yards to the north she would not have struck Enderby Island and the resulting: wreck with its great loss of life wou uld not. have occurred. The first ‘cattle landed on the Auckland Islands were those introduced by Captain Enderby when he made the unsuccessful attempt to found the Enderby settlement in 1850. These cattle were all killed ‘off by sealers. In 1894 cattle were landed by the Hinemoa on Enderby and Rose Islands in Port Ross. A number still live and breed on Enderby and it was from this place that the coast-watchers on the Aucklands drew their main supply of fresh meat. The cattle are really wild and the beefhunters almost had the positions reversed on occasions, they themselves becoming the hunted. Only the help of modern firearms saved the day at times. The stunted rata forest of Enderby Island is fast being reduced by the cattle, which also feed on the kelp washed ashore on the beaches. On Campbell Island there are about a dozen head of cattle, of seemingly Ayr-shire-Shorthorn cross. They were probably introduced in the sheep-run days and are not increasing greatly. They stop on one corner of the island and do not shift from there. _ Sheep and Goats Sheep were liberated on the Aucklands at. various times since 1890 but apparently failed to survive. This failure is most fortunate in the case of Adams Island which to-day is one of the few untouched and unspoiled islands in the sub-antarctic. ». Sheep were also liberated on the Campbells about 1890. In 1896 the island was taken up as a sheep run, some thousands of sheep were introduced, and a dwelling-house, wool-shed, yards and dip were built. In 1903 it was recorded that there were about 4,500 sheep and in 1907 about 8,000. The distance from the market and, probably, the unfavourable weather, caused the run to be deserted in 1927, several thousand sheep being left behind. Little remains to-day \ the various animals intro-

to show the enterprise of the past. The shepherd’s cottage, the wool-shed and yards, are almost flattened to the ground. Old roofing-iron, broken and rotting timber, grindstones, broken chains, enamelware and other debris of civilisation lie in heaps, mute reminder of work begun in high hope and abandoned hurriedly. There are now about 2,000 sheep on the island which, despite inbreeding, are still recognisable as a Merino-Romney cross. Long-tailed, of course, and carrying up to four fleeces or the remnants thereof, they look a bit woebegone. Nevertheless they are surprisingly agile, as those who have hunted them can testify. They are healthy, too. No disease has been noted among those killed for mutton, and no trace of footrot is evident. It is doubtful if they will survive a great length of time, however, for the lambing percentage has dropped to about 30. Much of the native edible verdure has been eaten off and various introduced grasses barely hold their own in favoured localities. The attempts made to acclimatise goats on southern islands are of interest. Captain Enderby landed some on the Aucklands in 1850 and Captain Norman landed more on Enderby and on the main island in 1865. Several were placed on Ewing Island in Port Ross in 1895

and they were later found to be plentiful on near-by Ocean Island. Captain Fairchild placed goats on the Campbells and later, in 1890, they were seen there. At a later day they had disappeared and apparently had died out. It seems strange that a hardy animal like a goat should die out while sheep should acclimatise themselves. To-day a hundred or so goats seem confined to the northern coast of the Auckland Islands but they are nowhere common. Their extermination should not provide a difficult task. Marauding Wild Pigs But, if the goats will be easily exterminated, the wild pigs which now overrun the main Auckland Island will provide a formidable task. The Campbells are clothed mainly in tussock but the Aucklands have a dense rata forest, with thick heavy scrub extending high into the hills. Through this scrub it is almost impossible to crawl or force a track, and pig-hunting in such country will be very difficult. The pigs are very numerous and do much damage to the beautiful native plants as well as to the birds. It will be readily appreciated that pigs, rooting among the burrowing petrels, will soon wipe them out. But their depredations do not stop with the smaller birds, for whole colonies of the beautiful and endemic Auckland Island shag have been destroyed, and the shy mollymawks are now compelled to nest only on steep slopes inaccessible to marauding pigs. Their introduction to the Aucklands came early in the history of the group. Captain Bristow discovered the islands in 1806 and in the following year liberated pigs there. Fresh stock was liberated at later dates. In 1865 Captain. Norman placed pigs on the Campbells but fortunately they failed to survive.

Wild dogs were reported on the Macquaries in 1820, but they later died out. They would be taken there by sealers as were those seen by Captain Musgrave when he was wrecked on the Aucklands in 1864. Here, too, they appear to have quickly died out. Cats, also, were seen on the Macquaries in 1820 and there arose in later years a mysterious story of "cat-rabbits" on the island, the peculiar animal supposedly resulting from a cross between a rabbit and a cat! Although biologically impossible and utterly absurd, the story persisted for some time. Needless to say no specimens were ever obtained. To-day wild cats are plentiful on the Aucklands and take a heavy toll of bush birds and the smaller burrowing petrels. They are in lesser numbers on the Campbells but do little damage there because there are now no native land birds and few small petrels. They certainly take large numbers of rats and probably do a certain amount of good in this respect. Rabbits, Rats, and Mice There are no written records of when rabbits were liberated on the sub-ant-arctic islands but presumably this took. place early in their history. On Enderby and Rose Islands, both in Port Ross of the Aucklands, rabbits are found. Those > on Enderby are known, at least recently, | as "French blues." Certainly they are not a grey nor does blue quite fit as a description of them. The fact remains they are very handsome and the posses- | sors of beautiful coats of a rich bluegrey shade. They are quite plentiful | and have reduced much of the island to_ a short turf. Despite ovet-crowding they | are quite healthy, but those on Rose. Island, a different race, are suffering from various rabbit diseases. I have a single record that rabbits were once liberated on the Campbells. Fortunately they failed to survive there. But rats are plentiful-only too numer-ous-on the Campbells. Their introduction was probably accidental just as it has been to most parts of the world. Strangely enough the rat is not found on the Aucklands although there are numerous mice there. The mouse was recorded from the Campbells but apparently died out. Rats on the Campbells are a decided nuisance, to put it mildly. They eat everything one would expect them to eat and many things one would not expect they would touch. Whilst we were coast-watching there, they ate our boots, our parkas and oilskins, they hollowed out onions and even ate the putty out of the boat! Only repeated trapping and poisoning kept them down-in the vicinity of the camp. Elsewhere they. ranged from seashore to mountain-top, moving in and burrowing all round a dead sheep or* seal and subsisting on grass roots, seeds and berries as well as shellfish ‘at other times. All the rats killed seemed healthy and in good condition.