Ecology and management of introduced ungulates in New Zealand

Abstract

Some fifteen species of ungulates are established in a wild or feral state in New Zealand : red deer (Cervus elaphus), fallow deer (Dama dama), Japanese or sika deer (C. nippon), Sambardeer (C. unicolor), Javan rusa deer (C. timoriensis) , wapiti (C. canadensis), Virginia or white-tailed deer (Odocoileus virginianus), moose (Alces aloes), chamois (Rupicapra rupicapra), thar (Hemitragus jemlahir cus), feral goat, pig, horse, cattle and sheep. For each of these species an account is here given of the liberation, spread since 1948, and present distribution. Some species (e.g. moose and sambar) are still confined to the vicinity of their original points of liberation, but other species (e.g. red deer and chamois) have spread into a variety of habitats and are still increasing in range and numbers. Information is presented on the effects of various ungulates on soils and vegetation. These effects are more serious in the beech (Nothofagus) forests than in the podocarp/mixed harwood forests because in the latter type, with more plant species available and better natural regeneration, an equilibrium is reached more gradually and at an earlier stage of depletion of vegetation. A combination of two or more ungulate species accelerates the rate of change. The end result in any case is a markedly different plant cover that protects the soil less efficiently. A brief history of the management of these ungulates is given and the methods, organisation and results of control are described. Of deer, for instance, over half a million were killed by Government hunters alone between 1932 and 1954, and the total number shot during that period cannot be less than 1,400,000 and could be as high as 3,000,000. A statistical analysis of the number of wild and feral ungulates destroyed between 1951 and 1958 suggests that there was no significant decline of the populations during that period.