§ THE EARL OF LISTOWELasked Her Majesty's Government—
- (1) How much annual damage is done by (a) rats, (b) rabbits:
- (2) How much money is being expended annually on research into (a) rats; (b) rabbits:
- (3) By whom is this research being undertaken:
- (4) What are the lines on which this research is being carried out.
§ LORD CARRINGTONThere is no reliable basis for assessing the annual damage done either by rats or by rabbits. An estimate was made in 1949 that the loss of food caused by rats and mice was about two million tons a year. The damage done by these pests is still considerable, although the indications are that the constant drive against them is yielding results. As to the damage done by rabbits, I would refer the noble Earl to the reply I gave to my noble friend Lord Rennell on 11th November last on this subject. As your Lordships are aware, I have recently introduced a Bill in this House seeking further powers to assist in destroying wild rabbits.
The annual expenditure on research is at present about £5,000 each on rats and rabbits. Research on rats is being undertaken by the Ministry of Agriculture and Fisheries; and on rabbits by the Ministry and the Nature Conservancy. A study is being made of the ecology and behaviour of ship rats under natural conditions. These investigations will shortly be carried a stage further in an animal watching house. An investigation is also being made of the distribution and behaviour of common rats in sewers with a view to improving control measures. On the general problem of rat destruction, a study is being made of the behaviour of rats in relation to baits, and tests are being made of a new anti-coagulant material for killing rats.
Recent research on the rabbit carried out by the Ministry has been mainly in the direction of trying to improve control measure but work is also being undertaken to assess the quantity of the damage caused by rabbits. Damage assessment studies have already been made 483WA in relation to winter and spring wheat and to pasture, and similar studies are contemplated for other crops. On the control side, special attention has been paid to gassing techniques. In particular a study has been made of the structure of rabbit burrows in relation to the penetration of fumigants, and chemical estimations have been made of hydrogen cyanide concentrations in burrows following pump gassing. In conjunction with these studies a small petrol-driven power machine has been developed which has been demonstrated to be more effective against rabbits living in extensive warrens than the ordinary foot pump. A study has also been made of rabbit repellants.
With the possible establishment in this country of myxomatosis, investigations are being planned to provide information on many unknown aspects of that disease. These will be carried out as a co-operative project by research staff in the Ministry and others in outside organisations and will result in an increase in the expenditure on rabbit research given above.
The research on the rabbit carried out by the Nature Conservancy is on different lines from that of the Ministry and includes a survey of the present rabbit situation on existing national Nature Reserves and on certain other sites of scientific importance; investigations on 484WA the habits and population of rabbit communities in the wild state in Great Britain; and a study of the effects of rabbits in herbage, shrub and tree growth.