Variability in shading behaviour of sheep

Abstract

During summer, a flock of 20 mature Merino sheep on irrigated pasture made virtually no use of shade, although similar sheep on adjacent pastures used shade regularly. In the following year on dry pasture and under comparable climatic conditions, the same experimental animals shaded frequently. In the second year. individual animals had consistent patterns of shade use, some animals shading for approximately 40% of the time, others scarcely at all. Unexpectedly, the extent of shade use was not significantly related to daily environmental heat load. For individual animals, the use of limited shade was not related to their position within a dominance hierarchy or a leadership rank in the flock. The results indicate that, even in summer, shading is not of high priority for all sheep. Animals vary in their inclination to use shade. This inclination may be modified by factors including possibly, microclimate in the pasture, preference for particular camp-sites, and aversion to human observers.