I cannot find when sheep were next brought into New Zealand, but as soon as settlement began they were freely imported from New South Wales. In those early days fences were very rough, and little or no attempt was made to keep sheep within enclosures. They were therefore allowed to roam freely over the open country, and were mustered at only rare intervals for shearing, tailing the lambs, culling, &c. It was inevitable, therefore, that numbers escaped the musterers, especially in high and inaccessible country, and that thus wild sheep became very common in the mountainous districts of the South Island.
Wild sheep are still abundant in some of the wilder parts of the country, and are especially numerous in the high limestone country of Marlborough. Much of this country is a _terra incognita_, for it is most inaccessible, except in certain rare states of the river-gorges, and very few people know anything about it. Mr. Aston, who recently visited this region on a botanical quest, says, “On the north-west side of Isolated Hill is a gently sloping tussock-land, stretching down towards the Ure River, on which are hundreds of wild sheep in small flocks of about half a dozen in each. All--rams, ewes, and particularly the lambs--are, as far as we could see, in excellent condition. Some were curiously marked and coloured. One had a brown body, black legs and face, and white forehead. The rams had large horns, and all were tamer than ordinary domestic sheep. Their food appears to consist of the silver-tussock (_Poa caespitosa_)--which was well eaten down--spear-grass, and several other native plants and shrubs.” In another part of his account he adds, “These sheep destroy the mountain-ribbonwood trees (_Gaya Lyallii_) by eating the bark, which we watched one stripping off in large sheets.”
In the district of Strath Taieri, in Otago, some forty years ago certain sheep on one of the runs--probably the progeny of a single ram--were found to be evidently short-winded. Apparently the action of the heart was defective, for when these sheep were driven they would run with the rest of the flock for a short distance, and then lie down panting. The result of this peculiar affection was that at nearly every mustering these short-winded sheep used to be left behind, being unable to be driven with the rest. Sometimes they were brought on more slowly afterwards, but if it happened to be shearing-time they were simply caught and shorn where they lay. As a result of this peculiar condition a form of artificial selection was set up, the vigorous, active sheep being constantly drafted away for sale, &c., while this defective strain increased with great rapidity throughout the district, for whenever the mobs were mustered for the market, shearing, or drafting, these “cranky sheep,” as they came to be called, were left behind.