High altitude ecology: Hare numbers and diet in an alpine basin in New Zealand
- Animal Ecology Division, D.S.I.R., Lower Hutt
The number of hares (Lepus europaeus) and their diet above the tree line in a 3100-acre basin at 4000-6000 ft. were assessed by tracking in snow, observing from a hide, and counting and analysing faecal pellets. About 8 hares lived on 300 acres of north-facing slopes, feeding chiefly on Chionochloa tussock and shrubs in winter and Poa colenso, in summer. These are dominant species of the grassland and hares are causing little damage relative to the 40-60 deer (Cervus elaphus) and chamois (Rupicapra rupicapra) present. The decay rate of faecal pellets decreased with altitude from a half-life of 7 months at 2000 ft. to over 3 years at 5000 ft. Population assessment by pellet counts involved so many variables and unknowns that it was better to count the hares, or their tracks or carcases, directly.