CONTROL OF RABBITS

Press, Volume LXXXIV, Issue 25609, 25 September 1948, Page 5

CONTROL OF RABBITS

Many Problems To Be Faced VIGOROUS POLICY NECESSARY A circular to hand this week seeking orders from the United States for rabbit-proof wire-netting will serVe as a reminder to many farmers, particularly those on the high country, how, in the past, they have been lulled into a false sense of security by using netting as protection against rabbits. American mills can supply unlimited quantities of galvanised wire-netting, including widths from 12 inches to 72 inches, mesh from three-quarters of an inch, and from 12 to 20 gauge. Even if import licences /were available, it is doubtful if many, if any, farmers would avail themselves of a chance of purchasing it for rabbit fences.

The problem of controlling the rabbit 10-day is so big, that to attempt to fence off land with wire-netting .would be courting disaster. Present indications are that the rabbit will only be controlled by a vigorous, well coordinated killer policy. In the ’eighties Canterbury was menaced by an invasion of rabbits from the south. It was thought in those days that the Waitaki river would prove to be an impassable barrier, but the rabbit had crossed rivers before. Almost simultaneously the rabbits were pouring into the Amuri county from Marlborough. A wire-netting fence, about 80 miles long, was erected in the south, and in the north the Hurugui rabbit fence ran inland 50 miles from the sea.

R. M. Burdon referring in his book “High Country,” to the southern fence, writes: “If such a fence could have been made across flat and unbroken land, it might, if continually watched, have formed an impassable barrier; but the rabbits made their attacks not on easy but on difficult country. Wherever the fence crossed a mountain stream, floodgates were necessary; and when that stream came down in swollen spate it washed them away and left gaps through which rabbits might pass. Wherever the fence ran oyer steep hills, rocks would become dislodged from above and, gathering momentum, would crash down on to it, or the running shingle would slip away beneath it. If natural forces failed to make a breach, the rabbit, always anxious to explore new country, would burrow beneath. Caretakers were employed to patrol the fence and to destroy any rabbits found within half a mile of it on the Canterbury side; but in spite of these precautions a few got through and reinforced those that had got in before the fence was made. The invasion was not entirely stopped, but it was at least checked.” Methods of Control Many methods of controlling the rabbit have been tried, and it appears that poisoning by phosphorised pollard is the most effective. Members of the New Zealand Rabbit Destruction Council who toured North Canterbury recently claimed that it had been a very effective method, particularly in' Hawke’s Bay, where a killer board had saved hundreds of thousands of acres which could easily have been overrun.

Strychnine has been used with telling effect in many Darts of New Zealand, but yielding to commercial interests which claimed that the carcase was affected and became unfit for sale, many rabbiters employed other methods, such as trapping, nets and ferrets and fumigation. A Marlborough rabbit board, operating in hard country, difficult to supply, has been using dehydrated carrots from the Marketing Department’s plant at Riccarton in recent months. It has been possible to take a larger quantity of carrots than pollard or oats* and when the carrots have been in water for the required time so much more bait is available. A big station near Hanmer Springs has also used dehydrated carrots. Until such time as commercial interests can be ignored, boards will find it difficult to make an all-out attack on the rabbit. A report prepared by the Department • of Agriculture in Dunedin and presented to a meeting of the Southland Council of Rabbit Boards showed that no one, generally, accepted the responsibility of dealing with the problem ‘during the main breeding season, in the spring and summer months.

“Ninety per cent, of the bal€s are offered during the months of April and October, during which period the rabbit skin sales are held twice a month,” the report said. “The remaining 10 per cent, is offered during the months from November to March, when the skin sales are held once a month.”

The report, prepared to prove th<t the rabbit was attacked as a means of profitable employment and not with the idea of extermination, said that the annual harvest was reaped when the most remunerative prices prevailed. An analysis of the approximate sources of supply of rabbit skins showed that 40 per cent, came from Otago, 33 per cent, from Southland, 20 per cent, from other parts of the South Island, and 7 per cent, from the North Island. As long as the value of the skins remained the incentive for the de-

struction of the pest towards elimination could not be real. “High skin values and liberal subsidies induce ‘pot-hunting’ rabbiting, and the residual position cannot be gauged by the number of rabbits destroyed. It is

quite safe to record that no permanent work results.” Value of Skins To dispel any idea that increased values, by current market value with or without subsidies, led to any spectacular improvement in the destruction of rabbits, the department prepared a table of figures showing the quantity and value of rabbit skins exported from New Zealand for the period 1937-47:

A survey of the number of bales handled by the trade a year, the average number being 4000 ( 480-5001 b per bale), would show that for the fiveyear period, 1943-47, the total number of bales accounted for was 2855 above the average total, said the report. In the previous five years the corresponding -figure above the average was 829. The approximate number of bales of rabbit skins handled by the trade in the years 1938 to 1947 was: 1938, 3821 bales; 1939, 3992; 1940, 4200; 1941, 4629; 1942, 3326; 1943, 4154; 1944, 4417; 1945, 4787; 1946, 5026; 1947, 4471. “Subsidies were first paid from the equalisation fund on August 11, 1942, and during the appropriate periods have continued up to March 2, 1948,” the report concluded. “During that period, in round figures, £600.000 has been paid in subsidies on rabbit skins. This monetary figure gives an interesting comparison with the net increase in destruction of 2000 bales plus some unmarketable smalls. Furthermore, the net increase cannot all be attributed to subsidies. The high current market values, culminating in the record prices in the winter of 1946, need to be taken into consideration; also the propaganda and commercial advantakes in the rabbit carcase trade. This greatly increased activity in the collection of rabbit carcases and extended widely the operational zones of rabbit collection lorries, which reached territory never explored for this purpose before.” I

Value Year. Number. £ ' 1937 .. 12,050,428 557,132 1938 10,268,012 247.390 1939 .. 11,190,294 262,904 1940 .. 10,412,156 401,716 1941 .. 13,403,673 1,006,238 1942 .. 11,818,761 745,742 1943 .. 12,200,284 903,241 1944 .. 13.886,065 ’ 974,909 1945 .. 17,670,078 1,204,791 1946 .. 15,755,939 1,451,301 1947 (9 months) 9,602,719 558,090