Chamois movements and habitat use in the Avoca River area, Canterbury, New Zealand

Abstract

Chamois subpopulations in the Avoca River area, Canterbury, New Zealand, had different migrant or resident behaviour, and aggregated into discrete high-use areas (varying in size from 1.7 km²–7.1 km²) that were defined by suitable terrain and vegetation. Chamois favoured patchy alpine grasslands and bluff grasslands above the timberline, but also used montane grasslands and shrublands on the lower slopes. They fed mostly on herbaceous vegetation and short-sward grasses (Poa spp.), but ate more shrubs (Dracophyllum spp.) in winter. High summer numbers declined by 20–54% in winter because of the diminished food supply. Resident females and sub-adults overwintered mainly in the area and more males than females migrated. Long-range movements up to 61.4 km extended throughout a 6000 km² area of Canterbury and Westland. Mean distances travelled were 18.7 km for males, 18.2 km for females, and 21.6 km for unknowns. Distances travelled for each sex were not significantly different, though females travelled less often than males. Migrant chamois had summer or breeding ranges in the study area, but wintered near the main divide or in Westland, travelling along major migration routes between these range areas. The main migration was composed of mainly females and young, and coincided with the snow-free period (November-March). A later breeding season migration comprised only adult males. Movement patterns of chamois reflected adaptation of the species to markedly different environments on either side of the main divide. These patterns could only be interpreted on a broad regional scale, in contrast to local patterns found in Europe. The large seasonal movements in the study area are as dynamic and wide-ranging as during the establishment phase 60 years ago.

Keywords:

• chamois
• Rupicapra rupicapra
• Harper-Avoca
• population density
• population dynamics
• migration
• habitat selection