Environment and the Sheep

Abstract

The wild ancestors of domestic sheep have evolved specialisations to exploit a diverse range of habitats and can survive in extreme environments, from the desert to the Arctic and sub-Antarctic. They can cope with poor quality diets, foraging on a wide range of plant types including cactus, fruit, lichens and seaweed. A consistent feature of wild sheep habitats, however, in addition to food and water sources, is escape terrain, as their main defence against predators is flight to cover. Seasonal and diurnal migrations about their home range occur in response to forage availability and safety. In domestic sheep, when given the opportunity to express these behaviours, similar habitat preferences and movements about the home range occur. Selection for breed traits and adaptation in domestic sheep has led to breed differences in environmental adaptation, seasonality responses and ability to cope with low food availability. Behavioural differences are also seen between breeds in social behaviours, antipredator responses, fearfulness, shelter-seeking and grazing behaviours. In general, the more specialised and selected breeds show the greatest tolerance for crowding and are the least responsive to predators or other fear-eliciting stimuli. The environments in which domestic sheep are kept do not accurately represent the wild situation, thus the ability of sheep to cope with thermal extremes, poor food availability and predation by behavioural means may be impaired.