red deer

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.

The diet of the North Island kokako (Callaeas cinerea wilsoni) was studied in three central North Island habitats, Pureora, Mapara, and Rotoehu, for three years. Possum (Trichosurus vulpecula) diet was less intensively studied for part of the same time in Pureora and Mapara. A literature review was made of the diet of possum, red deer (Cervus elaphus), and feral goat (Capra hircus). There is considerable overlap between the diets of kokako and the three mammalian browsers; leaves and/or fruit of some species are eaten by all four, e.g.

There has been considerable ongoing debate about the extent to which the impacts of introduced deer on native vegetation have replaced those of moa, and since the 1980s there have been major changes in thinking about the impacts of deer and ratites on ecosystems. Although it has long been known that deer caused a predictable sequence of changes in forest understorey composition, recent work has shown that the foliage of species preferred by deer contains lower concentrations of fibre – and decomposes faster – than avoided species.