Selection of upland swards by red deer (Cervus elaphus) on Rhum.
Abstract
In 1965-67 the use of sward types by red deer on Rhum was assessed from faeces counts within a 750-ha study area and by observations of deer dispersion in daytime. Ground with herb-rich grasslands and species-poor grasslands was used most in summer and flushed grasslands most in winter. Seasonal use of heaths and bogs fluctuated irregularly in different parts of the study area, but some parts were little used at any time. Coastal areas and the lower parts of the glens were grazed heavily in winter and high ground around 2 hills in summer. Grasslands covered one-third of the study area but sustained 60% of all grazing; heaths and bogs covered the remaining area and were grazed correspondingly less. Herb-rich grassland was more abundant on ground used by hind groups than by stag groups and was selected by hinds in summer. Stags were less selective than hinds and used species-poor and flushed grasslands most, but these were common on their ground. Mean seasonal densities of feeding deer on grassland sward types ranged from 0.2 to 0.8 deer/ha and on heaths and bogs from 0 to 0.2 deer/ha. Red deer on Rhum showed the same broad preferences for sward types as did Soay sheep and hill sheep on comparable range elsewhere.