RODENTIA--RABBITS.
Everybody in New Zealand knows something about rabbits; a great many
know a good deal about their habits, their value for fur and for
gastronomic purposes, and their destructiveness; but very few know
about the history of their introduction.
Probably every one knows that the rabbit (_Lepus cuniculus_) is a
burrowing-animal, which thrives particularly in more or less dry
regions. A wet climate does not suit it, and although there are regions
in New Zealand where rabbits are to be met with but only rarely, yet,
as a general rule, they are particularly abundant where there is a
limited annual rainfall. They increase at a great rate, the female
producing several litters of young in a season, and commencing to breed
when about six months old. The young are born blind and naked, and are
housed by the mother in a warm nest which is lined with fur pulled from
her own body.
Rabbits have long been domesticated, and several well-marked breeds
have been developed. For example, in the “lop-eared,” the ears are
large flaps pendent on each side of the head, and often touching
the ground. They are of many colours--white, black, brown, and
fawn--sometimes of one nearly uniform hue, but more often mixed. It is
clear that many of our New Zealand wild rabbits are descended from tame
ones, for they still retain their mixed colours. Albinos, with white
fur and pink eyes, form a distinct variety by themselves, and breed
true. The Angora rabbits have long fur, and are nearly always albinos.
The introduction of the rabbit into New Zealand has produced such
far-reaching effects and wrought such changes throughout the country
that it requires more than the sober language of the naturalist to
describe them. One thing is quite certain--namely, that the animal
was deliberately introduced into the country not by one individual,
but by numbers of persons, and by several acclimatization societies.
But no one will accept the blame for their introduction, so I may as
well detail all the facts known to me about their early history in New
Zealand.
According to the Rev. Richard Taylor, author of “Te Ika a Maui,”
the early missionaries were the first to introduce rabbits into the
country; but, unfortunately, he gives no dates. If he is correct,
however, they were almost certainly brought from New South Wales to the
far northern part of the colony between 1820 and 1830. They probably
never increased to any great extent, for, though there are rabbits in
a few localities north of Whangarei (I will specify localities later),
they are scarcely a pest there.
I am told that Jerningham Wakefield reported them as being placed on
Mana and Kapiti Islands, in Cook Strait, in 1840 or 1841, but I cannot
find any verification of the record. The first definite notice I have
discovered is in Mr. Tuckett’s diary of his expedition to the South
Island, which is printed as an appendix to Dr. Hocken’s “Contributions
to the Early History of New Zealand.” Speaking of the country between
the mouths of the Clutha and Mataura Rivers, Tuckett writes, under
date the 19th May, 1944, “Palmer has grown wheat and barley as well as
potatoes, and has plenty of fine fowls and ducks and some goats....
Returning from Tapuke [Taukupu], we landed on the island, and, with
the assistance of a capital beagle, caught six rabbits alive and
uninjured.” He does not say whether any were liberated on the mainland,
nor whether it was possible for those on the island to get ashore.
Mr. James Begg, who has given me some very valuable information as to
the earliest attempts to introduce these animals, tells me that “when
Willsher and party settled at Port Molyneux in the early ‘forties’
they sent to Sydney for rabbits, but whether they obtained them or
not I am unable to say. From early days there was at least one colony
of rabbits on the upper Waitaki. These remained quite local in their
habits, and did not increase to any great extent. They were finally
overwhelmed by the invasion of the grey rabbit from the south. The
late Mr. Telford, of Clifton, introduced some rabbits and bred them in
hutches till they numbered about fifty. They were then liberated on
Clifton, near the banks of the Molyneux, but died out in a short time.
This was about the year 1864. Mr. Clapcott also liberated some at the
old homestead at Popotunoa Station [Clinton], but they also failed to
thrive, and disappeared. It is probable that there were other attempts
to acclimatize rabbits, all more or less unsuccessful.”
From the point of view of a naturalist the failure of these attempts
is very interesting. It shows that there is a vast difference in the
aggressive power of the various breeds, for the country on which these
various lots of rabbits failed to make good has since been completely
overrun by other rabbits. It may be that they were unable to establish
themselves until a certain amount of clearing had been done, and till
a considerable number of wekas had been destroyed by tussock fires and
other means. Whatever the cause, it is the case that no rabbits were
able to establish themselves freely in New Zealand before 1860.
Dr. Menzies, who was at the time Superintendent of the Province
of Southland, is usually credited with having been the successful
introducer of them to the south of the South Island, an achievement
the credit of which has not been very eagerly sought after. They were
liberated on the sandhills between the ocean and the New River, a place
known as Sandy Point.
According to Mr. Huddlestone, silver-grey rabbits were first introduced
into Nelson in or about 1865; but there is no record as to what came of
this importation. Sir George Grey also appears to have introduced them
at or about the same time, for in the annual report of the Canterbury
Acclimatization Society in 1866 it is said that “an enclosure has been
set apart for the silver-grey rabbits presented by Sir George Grey,
which have thriven well and increased to a great extent, and _have
been distributed to members far and near_.” Later in the same year the
society passed this minute: “The suggestion of giving as a reward for
the destruction of hawks and wild cats some silver-grey rabbits was
approved.”
There is a very popular impression that the Otago Acclimatization
Society has no responsibility in connection with the rabbit plague.
Well, here are the figures taken from one of their own reports: “In
1866 the society liberated sixty rabbits, twenty-three in 1867, and
eighteen in 1868. There is no record as to where these came from.”
These are the only records I have been able to secure so far as to
the introduction of rabbits into this colony, but there is still a
source of information to be searched--namely, the publications of
the Provincial Government of Southland. But there can be no doubt, I
think, that what happened in the south happened elsewhere at every
port where settlement took place, and that private individuals at
Nelson, Wellington, New Plymouth, and Napier also imported rabbits.
But when the animals became a pest, and their increase was recognized
to be a calamity to the country, every one was desirous of repudiating
the responsibility for their introduction. Thus the framer of the
annual report of the Canterbury Society for 1889, not having read
the statement in the report for 1866, says, concerning “the rabbit,
that great scourge to our large runholders--that the introduction of
these cannot be laid to the charge of this society.” Similarly, Mr. A.
Bathgate, of Dunedin, in 1897, wrote, “It is to them [the Provincial
Government of Southland] that we are indebted for the presence of the
rabbit.”
The repudiation of the responsibility for the rabbits is almost
as funny as that for the sparrows. As soon as an animal turns out
differently from what was expected of it, and becomes a pest instead of
a blessing, then no one will admit having had anything to do with the
initial mistake of bringing it into the country.
From 1866 onwards the spread of the rabbits was phenomenal. I quote
part of Mr. Begg’s account of this increase: “About the year 1874 they
began to make their presence felt in an unpleasant manner. By 1878 they
had reached Lake Wakatipu, leaving a devastated country behind them.
At the same time they had reached as far east as the Clutha River, and
in a few years later had overrun the greater part of Otago as well as
the whole of Southland. Those were evil days for farmers in that part
of New Zealand, and especially for the squatters, who occupied large
areas of grazing-country. The fine natural grasses on which the sheep
and cattle grazed were almost totally destroyed. Sheep perished from
starvation by hundreds of thousands, and it is no exaggeration to say
that the majority of the squatters were ruined. On the old Burwood
Station the number of sheep fell in one year from 119,000 to 30,000.
This was partly due to heavy snow, but the rabbits prevented any
recovery. It is doubtful if the same country to-day carries more than
40,000 sheep. From the year 1878 onwards immense areas of grazing-land
were abandoned, as the owners gave up the unequal struggle with the
rabbits. In the early days hunting with dogs, shooting, digging out the
warren, poisoning with various baits, and trapping were the methods by
which farmers tried to rid themselves of the pest. Later, wire netting,
the introduction of stoats, weasels, and ferrets, fumigating the
burrows with poisonous gases (such as carbon disulphide and hydrocyanic
acid), and the stimulus given to trapping by the export trade in frozen
rabbits, have been relied upon to reduce their numbers. In the writer’s
experience practically no progress was made in reducing the numbers
of rabbits till about the year 1895. From that year there has been a
steady diminution. For twenty years the rabbits had the upper hand,
and, though many millions were killed annually, no reduction in their
abundance was noticeable. In the last twenty years there has been a
steady decrease. Large areas of hill country in the wetter districts
are now completely clear of rabbits, though they still persist in
favourable situations. In the dry country in Central Otago they are
still very troublesome and very vigorous, and their evil effects are
there seen on hundreds of square miles of country, once the finest
grazing-land in New Zealand, now little better than a desert.”
It must not be assumed that every one regards the rabbit as a nuisance.
Many a successful farmer of to-day got a start as a rabbiter. The
killing of rabbits actually became one of the principal industries of
the province. Their presence directly led to the subdivision of large
estates, and may have been quite as effective in this direction as all
the legislation on the subject. Since the war rabbit-skins have become
extraordinarily valuable, so that, instead of landholders paying for
the destruction of rabbits, rabbiters offer premiums for permission to
go on to land to trap the rabbits.
The introduction of rabbits had a lasting effect on acclimatization
generally. Before their advent partridges and pheasants had become
numerous, but they have entirely disappeared in Otago. In the effort
to cope with the rabbits the country was annually sown with poisoned
grain. This had a disastrous effect on both native and imported game.
Had rabbits not become a nuisance it is unlikely that weasels and
other vermin would have been introduced. These animals are largely
responsible for the decrease in the numbers of native birds, and also
make the successful introduction of new varieties more difficult.
The economic waste caused by the vast increase of rabbits in New
Zealand is incalculable, and certainly represents a loss in the
stock-carrying capacity of the country which probably runs every year
into millions of pounds. It is not only that they eat up food which
would support some millions more sheep than are at present reared, but
they destroy large areas of country, and yield very little return for
the damage they do. The annual export of approximately three million
rabbits, valued at (in pre-war times) about £70,000, and of some eight
millions of skins, valued at about £115,000, is all the return they
give, but it represents only a small proportion of the pest. In all
parts where rabbits abound their destruction entails a heavy expense
on the occupiers of the land. There are no data available to enable
any one to estimate how many rabbits are destroyed every year, but far
more are killed by phosphorus than by trapping. The latter method alone
furnishes any statistical data; the former is an unknown quantity, but
it represents a very large figure.
Probably the most ghastly exhibition of the work of rabbits is to be
found in the grass-denuded districts of Central Otago, parts of which
have been reduced to the condition of a desert. It is improbable that
this state of affairs could have been brought about by rabbits alone.
Before their advent the runholders who had possession of the arid
regions, in which the rainfall probably averages 10 in. to 12 in.
annually, and certainly never exceeds 15 in., were doing their best
to denude the surface of the ground by overstocking with sheep and
by frequent burning. The latter was resorted to because many of the
large tussock-forming grasses, especially such as the silver-tussock
(_Poa caespitosa_), yielded coarse and rather unpalatable fodder, but
after burning the tufts a crop of tender green leaves sprung up, which
were very readily eaten. Unfortunately the burning not only got rid
of most of the coarse growth of the tussocks, but it also swept off
the numerous bottom grasses which occupied the intervening spaces,
which were the mainstay of the depasturing flocks. Even before the
rabbits arrived the work of denudation of the grass covering had been
proceeding apace through the causes mentioned. Thus Buchanan, writing
in 1865, said, “It is no wonder that many of the runs require 8 acres
to feed one sheep, according to an official estimate.” Mr. Petrie
thought this an unduly severe estimate, “as in the mid-‘seventies’ the
sheep-runs of Central Otago were reputed to carry at least one sheep to
3 acres, or somewhat less.”
Mr. Petrie, who has reported to the Department of Agriculture on these
grass-denuded lands of Central Otago, knows more about this subject
than any one else who has written on it, and I quote him at some
length. He says, “Before the rabbit invasion began the hill-slopes
carried a fairly rich and varied covering of tussock and other grasses,
and, except on the steeper rock and sun-baked faces, had not been
seriously depleted even in the early ‘nineties.’ The earlier stages of
this depletion may now be seen in several of the Central Otago ranges,
as on the spurs of the Rough Ridge and the Morven Hills districts.
The northern slopes of the spurs are almost, in many instances,
entirely bare of grass, while the southern shaded slopes still carry
a fair amount of pasture. The grass covering generally stops abruptly
at the bottoms of the valleys, even when those are not worn into
water-channels. The vastly greater depletion of the pasture on the
northern slopes is easy enough to understand. They are more exposed to
the sun and to the frequent violent parching north-west winds; they
lose their covering of snow earlier in spring than the southern slopes,
and are thus more closely grazed at a critical season for the pasture;
and sheep at all times show a preference for feeding on the warmer
sunny slopes. When the pasture on the exposed slopes fails, that on the
shaded slopes has to feed all the stock that is about, and unless the
stocking is reduced to meet the new conditions the remaining grasses
are sooner or later eaten out. The desert, with all its problems, is
then established.”
In his account of how desert conditions arise in Central Otago Mr.
Petrie refers only to the effects produced by sheep, because it is the
loss in sheep-carrying capacity which is so serious; but later on,
after describing a typical specimen of the country, and showing that
in inaccessible situations a considerable variety of vigorous grasses
live on, he adds, “This is one of the facts that go to indicate that
the extermination of the grasses in this desert country is mainly due
to eating out by overstocking, rabbits as well as sheep being included
among the stock carried.... The desert and the greatly denuded lands
are not wholly destitute of vegetation. In most of their lower areas
greyish, flattened, firm, nearly circular patches of scabweed (_Raoulia
australis_ and _R. lutescens_) are thickly dotted about the bare
ground. Though otherwise useless, these moss-like composite plants help
to keep the soil from being blown or washed away, and when old supply,
in the decayed centres of the patches, spots with some amount of humus
where grass-seeds can more readily settle and grow.” These plants are
never eaten by either sheep or rabbits.
In regard to other native plants, rabbits have nearly exterminated the
wild spear-grasses (_Aciphylla squarrosa_ and _A. Colensoi_), which
used to be so abundant. They particularly attack these plants when the
ground is covered with snow. Mr. Petrie, writing me three years ago,
said, “When I first visited inland Otago, in 1874, _Aciphylla Colensoi_
was most abundant. In riding about it was almost impossible to deviate
from well-beaten tracks or roads because the spines pricked the legs
and feet of the horses.” In later years these plants have become
rare. Captain Hutton, writing me in March, 1892, said, “As to the
extermination of the wild-spaniards (_Aciphylla_), I believe it to be
due to rabbits. When I was in the Nelson District in 1872-73 there were
no rabbits on the eastern side of the Upper Wairau near Tarndale, but
they were abundant on the western side. Spaniards were abundant on the
eastern side, but almost destroyed on the western. The rabbits seemed
to burrow under the plants, and then eat the roots.”
Several species of _Celmisia_ (notably _C. densiflora_) have been
greatly checked, and others are almost exterminated. Mr. B. C. Aston,
in his ascent of the Kaimanawas in 1914-15, found that at a height of
4,200 ft. _Panax Colensoi_ was nearly exterminated by rabbits, which
had ring-barked all the young trees. This mischief is done after heavy
falls of snow, when the rabbits are driven down from the tussock-land
into the gullies of the scrub and forest zones. Trees of _Panax
Edgerleyi_ from 19 ft. to 20 ft. high were found to be ring-barked and
dead.
In a good many rabbit-infested districts, particularly in the North
Island, these animals have aided very materially in producing a certain
amount of erosion and washing-down of alluvium by burrowing extensively
in the banks of rivers and small streams. When floods came down, these
undermined portions were commonly swept away where the firmer banks
resisted the impact of the water. Dr. C. A. Cotton, of Wellington,
considers that this action has caused a slight rejuvenation of erosion
in certain districts and river-systems. Cattle, sheep, and goats
assist in this work, but rabbits are the most active agents in it. The
Rev. A. Don, writing to me in 1901, said, “The rabbits, by stripping
the ground of vegetation and burrowing into the faces of the slopes,
are converting what were once nice green hillsides into shingle-slopes,
because when once the face is so bared and its surface broken it begins
to slip.” Mr. Petrie also refers to this process in his report, as
follows: “The soil on the grass-denuded slopes, which is by no means
infertile, being no longer held together by the roots of plants, is
being rapidly removed by wind and rain, and pebbles and angular stones
are now closely dotted over great stretches of hillside that not many
years ago were covered with soil. On the steeper slopes, indeed, the
soil is being rapidly sluiced down into the gullies and thence into the
river, and deep, narrow, chasm-like watercourses are being dug out.”
I was at one time under the impression that in this new country, where
the causes--especially the natural enemies--which kept them in check
in their original home were wanting, and there seemed to be nothing
to arrest their development in any direction, there might arise new
varieties of rabbits, with modified habits, structure, &c. Particularly
did it seem likely that colour variations would thrive unchecked, and
the traveller passing through certain districts in Otago is certainly
surprised at the number of conspicuously coloured animals to be seen.
I was down at Romahapa recently and saw some rabbits at the edge
of the bush, and among a dozen of them there were some with white,
buff, and black. I was informed also that there are a number of them
in the district with a white ruff round the neck. Other observers
bear me out in the prevalence of coloured varieties among the wild
rabbits. Thus Mr. W. H. Gates, of Skipper’s, a keen observer of nature,
writing me two years ago, said, “As for colour, they are of all
colours--grey-and-white, tan-and-white, grey with a black ridge down
the backbone, grey with a white ring round their necks, cream with a
darker shade down the backbone, and buff.” Other observers speak of
the prevalence of black, black-and-white, and yellow rabbits. Grey is
certainly the best colour to hide a rabbit in sandy ground covered
with somewhat dry herbage, and in a district like Central Otago, where
rabbits are as “thick as locomotives”--as a certain Gaelic acquaintance
of mine with a limited knowledge of English and of locusts put it--one
can almost walk over the rabbits, as long as they sit still, without
seeing them. The warning white tail of the rabbit is a danger-signal to
other rabbits, for whenever a rabbit is running for shelter its white
scut warns all the others which it passes to run also. To find out with
some approximation of accuracy whether my idea of the prevalence of
coloured rabbits was correct or not, I applied to Mr. R. S. Black, of
Dunedin, who is a very large exporter of rabbit-skins, for information.
Mr. Black informed me that, while they are of all colours, yet 95 per
cent. of the skins exported are grey. The other colours appeal to the
eye, but they are not so common, after all.
That the rabbits of aberrant colours should survive is not to be
wondered at, seeing that in this country there are no foxes, and
neither owls nor hawks large enough or active enough to tackle a
full-grown rabbit. The common harrier hawk takes a considerable toll
of young rabbits, but is quite unable to keep them in check. In many
districts wild cats live mainly on rabbits.
I have from the far north an interesting record of a curious habit
among rabbits. Mr. Yarborough, of Kohukohu, writing in August, 1916,
tells me that rabbits became quite common in a district near Kawakawa,
at the head of the Bay of Islands, many years ago. Recently they have
reached the eastern side of the Hokianga River, and it is not unusual
to see them occasionally. Then he adds this interesting statement:
“I have never heard of any rabbit-burrows, as they appear to breed
among the rocks and roots of trees.” Another observer from an adjacent
district says that these animals are not uncommon near Kaikohe, where
they do make shallow burrows. The comparatively heavy rainfall of
Hokianga, amounting to from 60 in. to 70 in. in a year, has no doubt
a good deal to do with the comparative scarcity of the rabbit in that
part of New Zealand.