Recovery of Northern Fiordland Alpine Grasslands after Reduction in the Deer Population

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 showed a strong preference for grasslands characterised by Chionochloa pallens and large-leaved herbs. These occur on fertile soils, and have shown the most recovery, especially at low altitude (c. 900-1100 m a.s.l.). Little change occurred in the less-favoured grasslands characterised by C. crassiuscula and C. acicularis on infertile soils. Several studies suggest the vegetation preferred by deer was some of the best former habitat of the takahe (Notornis mantelli), an endangered rail. Little competition from deer would now occur if takahe were reintroduced on to these sites, providing intensive aerial hunting continued.