In late 1986 an official deer hunting regime in the Murchison Mountains, Fiordland, was compared with two commerical aerial hunting regimes in the adjacent Stuart Mountains by measuring the density of deer faecal pellet groups. Overall densities in the Stuart Mountains were twice those in the Murchison Mountains. Official hunting appeared to be more effective than commercial hunting at reducing and controlling deer densities in heavily forested catchments, but not in catchments with less extensive forest cover.
A significant recovery of food plants preferred by introduced deer (Cervus elaphus) occurred between 1969 and 1984 on 57 permanent plots in the alpine grasslands of northern Fiordland. During this period the deer population was reduced markedly by hunters operating from helicopters.
Deer density indices were estimated in 1969, 1975, and 1984 in the core of the Wapiti Area of Fiordland National Park. Between 1969 and 1984, density above timberline was reduced to near zero by commercial airborne hunting, with smaller decreases in the forest. Overall density declined by 81%. An estimated 2007± 385 deer were present in the 850 km2 survey area in 1984, with an average density in the forest of 3.47±0.66/km2. The highest densities remained in the most completely forested sub-area (Catseye).
Forest types of the Wapiti, Doon and Glaisnock catchments, ranked in order of proportion of preferred food species for deer, paralleled a gradient of landform stability. Seral forests and low altitude silver beech forests were preferred deer habitat because they contained the largest proportions of highly preferred species. They often occurred on unstable landforms such as debris cones, colluvial sideslopes, and terraces with recent and compound soils, assumed to be of high nutrient status.