Distribution and diet of chamois (Rupicapra rupicapra) in Westland forests, South Island, New Zealand

Chamois (Rupicapra rupicapra) are usually considered an alpine species in New Zealand, but also occur in forests in areas such as Westland. A postal survey of commercial helicopter-based hunters indicated that chamois are present within Westland forests from timberline to sea level and are most abundant within an area of about 1600 km(2) extending from the Wanganui River in the north to the Karangarua River to the south. The diet of 40 chamois shot in spring and summer was determined by analysis of rumen contents. Of 66 food items identified to genus or species level, five averaged >5% of dry weight of the rumen contents; these were Carmichaelia spp. (14%), large leaved Coprosma spp. (12%), Weinmannia racemosa (11%), Griselinia littoralis (9%), and Melicytus ramiflorus (7%). The proportion of grasses in the diet was significantly lower in summer (3%) than in spring (8%). These results suggest that unmanaged chamois populations have the potential to affect regeneration of plant species important to the Westland Metrosideros umbellata—Weinmannia racemosa forest community.