Farmed red deer home range, habitat use and daily movement patterns in a Southland, New Zealand, tussock grassland over calving and lactation.

Considerable expansion of deer farming has occurred in New Zealand’s South Island high country. On these farms, red deer breeding hinds are usually continuously grazed (set-stocked) at low population densities in large highly-modified native tussock grassland paddocks over their calving and lactation seasons. This study determines how these hinds use the tussock grassland over this critical period, identifying the most essential resources for the hinds and also some potential long-term consequences of their behaviour on the grassland ecosystem. This was achieved by tracking 9 GPS collared hinds over 2 years on a high country deer farm in Te Anau, Southland, New Zealand. The home ranges of the hinds varied widely, occupying between 15–52% of the grasslands total paddock area. Vegetation dominated by naturalised exotic pasture species covered the greatest area (>60%) of 8 out of 9 hinds home range. In contrast, tussock-dominant vegetation home range coverage was far more variable (0.4-46%), with several indicators suggesting this vegetation type was being used as a substitute for pasture areas under high intra-specific competition between the deer. Both pasture- and tussock-dominant vegetation was used in proportion to its availability. In contrast, shrub-dominated vegetation was used less than in proportion to its availability, indicating this vegetation type was not being put under as much foraging/grazing pressure. This has implications for this vegetation type’s further paddock ingression over time. However, shrub-dominated vegetation did consistently form a small proportion (8-17%) of each hind’s home range, and its usage increased particularly in the mid-afternoon when hind daytime movement activity was generally low. Indications were that this vegetation was used by hinds for sheltering in while resting or nurturing their calves, which has potential implications for paddock soil nutrient transfer over time. There was clear evidence that certain paddock topography was also being mainly selected for by the hinds, namely steeper and higher altitude areas of the paddocks. Based on these finding, some potential methods for aiding in management of these extensive tussock grassland paddocks under deer grazing are suggested.