CARNIVORA—FERRETS, STOATS, AND WEASELS.
The Mustelidae, or weasel family, is the most heterogeneous assemblage of all the carnivorous group. Though differing much among themselves, they possess certain important characters in common. One of the most familiar is the presence of anal glands, situated beneath the root of the tail, which contain a more or less noxious and evil-smelling fluid. The three members of the family which have been introduced into New Zealand belong to the genus Putorius, which receives its name from the Latin word putor, a stench. The most notorious example is the American species, the skunk, whose perfume is so strong that David Harum records how a man who killed one went into the woods for a week and “hated hisself.”
Of all intentional introductions to this country that of the animals of this family is the most unfortunate and undesirable. The history of the business is, to my mind, a depressing one, for it shows what people are prepared to do to save their own pockets, whatever the effect may be upon others. These animals have not done what was expected of them—namely, suppressed the rabbits, or even kept them in check, but they have exercised a most baneful influence on the bird-life of the country. The characteristics of the three species are somewhat similar. They have been called vermiform animals, for they have a singularly worm-like appearance. The body is long, narrow, and cylindrical in shape, while the legs are relatively extremely short. The neck is also very long, and bears a small, flattened head; the eyes are small, savage-looking, and glittering.
The ferret is closely allied to the polecat, but is a domesticated variety, and is zoologically interesting, because it is a true-breeding albino, having white fur and pink eyes. It originated in Africa, and retains this characteristic of its warm origin: that it is unable to endure great cold; hence if it goes wild in New Zealand it usually survives only in warm and sheltered localities. It is from 12 in. to 15 in. long, and is a stouter animal than either of the others. Though a semi-domesticated animal, it never shows the slightest affection for its master, and has usually to be kept in confinement. My son, Dr. Allan Thomson, tells me that about Kekerangu, in Marlborough, wild ferrets are at present very numerous.
I have no record of the introduction of the true polecat (Putorius foetidus) into these Islands; but some five or six years ago Mr. Anderton, curator of the Portobello Marine Fish-hatchery, shot two animals which were too large for stoats, being about 18 in. long. They were not ferrets, in that they were brown-coloured. Unfortunately he did not keep the bodies, their smell, for one thing, being so offensive; so their specific character was not determined.
[J. Macdonald, photo.
Fig. 9.—The Ferret.
The stoat is about 1 ft. long and is somewhat distinctively coloured. “In summer the upper parts vary from yellowish-brown to mahogany-brown, while the underside is white tinged with sulphur-yellow, except on the throat, which is pure white. The tail is tipped with black. The brown upper and white under surfaces are separated by a perfectly distinct line of demarcation, which extends from the snout to the root of the tail, dipping down at the limbs, so as to include the outer surfaces of the latter in the dark area. In winter, on the other hand, the skin is—with the exception of the tip of the tail, which always remains black—pure white, tinged here and there with sulphur-yellow. Intermediate states between full winter dress and full summer dress are often found.” In winter, when the fur is white, the animal is known as the ermine, and white stoats are well known in winter in the South Island. The favourite food of the stoat consists of rats and mice, but it is fond of birds, and thus is a danger in a poultry-yard. It occasionally attacks lambs. These creatures seem often to kill for the mere sake of killing. In my boyhood days I at one time kept a large number of rabbits in an enclosure. One night a stoat got in and killed the whole lot—over a dozen—and left each with a hole in the back of its head. These animals are fairly abundant over New Zealand at the present time.
[J. Macdonald, photo.
Fig. 10.—The Stoat.
One is frequently asked what is the difference between a stoat and a weasel. According to one authority, the one “is stoatally different from the other, and weasely distinguished.” But this does not help us much. The weasel “in length, from snout to root of tail, does not exceed 8 in. The tail is about 2 in. long. The fur is light reddish-brown above, and white below.” The size and black-tipped tail best distinguish the stoat. The weasel is a good climber, and makes use of its skill in this accomplishment to prey upon birds, their eggs and young. Rats and mice are its favourite food.
[J. Macdonald, photo.
Fig. 11.—The Weasel.
The history of the introduction of these vermin into this country is characteristic of the acclimatization methods of the past. Ferrets have been introduced from early times by dealers in birds and animals. The first authentic record is that of the Canterbury Acclimatization Society, which received five in 1867. They were apparently not liberated, nor were subsequent introductions for some time. When rabbits began to increase to an alarming extent various suggestions were made as to the importation of what was called “the natural enemy.” The fox is the real natural enemy of the rabbit, but this was too risky a proposal to be made. The Victorian Government had already allowed some idiots to introduce foxes into that country in order to allow them the pleasures of fox-hunting, and the result has not been encouraging. One well-known public man in New Zealand proposed to introduce Arctic foxes “because their fur would be so valuable.” When it was pointed out to him that they would probably prefer lamb to rabbit, he replied that, as they did not know anything about lambs in their native haunts, it was improbable that they would take to eating them in New Zealand. Fortunately his proposal was not given effect to. Meanwhile sheepowners brought pressure to bear on the Government, and as a result steps were taken to obtain ferrets. Numbers of these were introduced in 1882, and in the following year Mr. Bailey, Chief Rabbit Inspector, recommended the introduction of stoats and weasels. To show the scale on which these recommendations were carried out, I summarize from Mr. Bailey’s reports as follows:—
(a.) In July, 1883, it is stated that since March, 1882 (fifteen months), the Agent-General had made thirty-two shipments of ferrets from London, numbering altogether 1,217 animals. Of these, only 178 were landed, at a cost of £953. Of 241 purchased in Melbourne, 198 were landed, at a cost of £224. Thus the total number landed was 376, and the cost £1,177, or £3 2s. 7d. per head. The natural increase was 122, but 157 died of distemper. At this period it would seem as if the Government kept a perfect menagerie of these animals. In the same year a substantial bonus was offered to any one who would introduce a certain number of stoats or weasels in a healthy condition.
(b.) In 1884 he reports “nearly 4,000 ferrets were turned out; 3,041 in Marlborough alone, and about 400 on Crown land in Otago.” The rest appear to have been sold to private individuals. It is evident that there was no study of the suitability of a semi-domesticated subtropical animal becoming acclimatized in this country, and, as a matter of fact, the ferret has not gone wild in the South Island to any great extent. Mr. Bailey also stated in this report that “an agent has been sent Home to procure stoats and weasels.” Mr. Rich, of Palmerston, imported some of these latter in a sailing-vessel, but how many I cannot learn.
(c.) In 1885 two lots of stoats and weasels were received from London—viz., 183 weasels (out of 202 shipped) and 55 stoats (out of 60). Of these, 67 weasels were released at Lake Wanaka on a peninsula of 8,000 acres, on which they reduced the rabbits, but by no means exterminated them; 28 weasels were liberated at Lake Wakatipu; 15 weasels near the Waiau River, in Southland; and 8 stoats at Ashburton. The rest were sold at Wellington, Christchurch, and Dunedin.
(d.) In 1886 the Government introduced two lots. Of these, 82 stoats and 126 weasels were distributed in about equal lots to the Wilkin River, the Makarora, at the head of Lake Ohau, and on the Waitaki; and 32 stoats and 116 weasels were distributed between Marlborough and West Wairarapa. A private shipment of 55 stoats and 167 weasels was also received for Riddiford’s station in West Wairarapa. The localities selected for these animals were those in which rabbits were most abundant. Mr. Bailey also reported that “ferrets were turned out by thousands,” but the success was only partial.
In the same year a meeting was held at Masterton to consider the administration of the Rabbit Act, and the best means of dealing with the pest. One of the resolutions carried was, “That the introduction of ferrets, stoats, and weasels in large numbers is in the opinion of this meeting the only means by which the rabbit pest can be successfully put an end to, and that every owner of land infested with rabbits should either turn out ferrets in proportion to his acreage or contribute to a fund for the breeding and purchase of ferrets, stoats, and weasels to be turned out in the district. That the landowners present form themselves into an association for the purpose of providing the natural enemies.” An association was accordingly formed with this object in view, large sums of money were subscribed, and hundreds of stoats and weasels were introduced into the district. Several of the acclimatization societies took strong exception to the action of the Government and of the sheepowners directly concerned; but as the societies were themselves directly responsible for the rabbits to a large extent their protests were ineffectual.
These animals have not exterminated the rabbits; they do not even keep them in check in most parts. They have, however, helped in the practical extermination over wide areas of many species of indigenous birds, for they have penetrated into quite unsettled and unbroken parts of the country, where apparently they feed on the avifauna.
Every one who has had any experience of these vermin has his own view as to their usefulness or otherwise, but it is seldom that careful observers put their experiences down on paper. I have collected some evidence on this subject, and give here a few of the observations which have been recorded.
Mr. George Mueller, Chief Surveyor of Westland, in his report on the “Reconnaissance Survey of the Headwaters of the Okuru, Actor, and Burke Rivers” (Reports N.Z. Survey Department for 1889–90, p. 50), says, “Several weasels and ferrets were caught and killed at the Okuru and Waiatoto Settlements, within about a mile from the sea-coast.... No rabbits were met with until near the Actor, nineteen miles from the coast, and they were only seen in numbers at the very headwaters of the Okuru.... Meanwhile the kakapos, kiwis, and blue ducks have nearly disappeared from the district.”
Mr. Richard Henry, writing from Lake Te Anau in September, 1890, says, “I have known the ferrets to take young paradise ducks out of a clutch often in 1888, and last year the same pair of ducks reared only two young ones; but away from the lake I have seen larger families. I found two black teal ducks killed by a ferret, though it is seldom any of their work is seen, for they always drag their prey under cover. The black teal are getting scarce.” Mr. Henry adds, “I think very few ferrets at liberty survive the winter for want of food.” My own opinion is that they cannot endure the cold.
Mr. Richard Norman, Albert Town, writing in the Otago Witness of the 2nd October, 1890, says, “I think that Mr. E. H. Wilmot’s experience in the Hollyford Valley, as recorded in the Witness a year or two ago, conclusively proves that the imported vermin kill the native wingless birds. He encountered there a ferret-warren, and the weka, kiwi, and kakapo were almost exterminated. In the Makarora Valley these used to be plentiful, but since the advent of the stoats and weasels they are very rare, and rabbiting tallies have not depreciated.”
Mr. Charles J. Peters, of Mount Somers, writes about these animals (1916): “Since the stoats and weasels became fairly numerous the rabbits have increased 100 per cent. and more. I have found weasels’ nests both in heaps of fencing-material and also in rabbit-burrows. These nests have always been made of skylarks’ feathers. I have also found parts of young hares at weasels’ camps, but never a sign of a rabbit.”
Mr. Yarborough, of Kohukohu (Hokianga), states that stoats and weasels do not seem to be so numerous now (1916) as they were some few years ago. At that time a great number of these intrepid little animals appeared on the eastern side of Hokianga Estuary, and were occasionally observed swimming across the river, which is about a mile wide. For the last year or more they have neither been seen nor heard of. The same observation has been made of the occurrence of these animals on the peninsula on which the Portobello Marine Fish-hatchery stands. Three or four years ago they were very abundant, but recently there are few to be seen.
In Taranaki a correspondent informed me last year that either stoats or weasels destroyed a litter of nine sucking-pigs in one night. Another informant states that “at Lee Stream, in the Taieri district, I saw a rabbit paralysed with fright and uttering squeals of terror, and on looking for the cause observed a stoat fully 10 ft. away walking deliberately towards its victim. The rabbit was killed by one bite on the neck. A few weeks ago a lady informed me that she had seen a somewhat similar occurrence at Brighton, but in this case the rabbit struggled to the lady for protection, and fell trembling at her feet, while the stoat disappeared.”
A few years ago stoats were fairly common in the suburbs of Wellington, and made great depredations amongst poultry, entering the fowlhouses at night. My son describes seeing a couple playing in a vacant section at Hataitai, and taking not the slightest notice of passers-by.