The influence of forage and climatic conditions on range community preference of Shorthorn cattle in central Australia.
In central Australia, grazing preferences of Shorthorn cattle for seven major and four minor range communities were determined from 108 aerial surveys over 4 years during climatic conditions ranging from drought to the wettest on record. Principal component analysis was used to summarize the variation in patterns of choice between communities. Variation in use was related to changes in quality and quantity of forage. Sporadic environmental disturbances such as excessive rains, drying out of watering points or cold winds disrupted the pattern of grazing determined by forage conditions. Woodland and Flood plain were the most preferred communities, particularly during good forage conditions, while hills and mulga-perennial grass communities were refuge areas during drought periods. Gilgaied plains and foothill fans were moderately used mainly during good to moderate forage conditions. This preferential use of different communities under different forage conditions showed the benefit of a complex of communities in a grazing system in allowing cattle to seek the best forage to maintain body condition. In such a complex, grazing distribution could be used as an indication of condition of the forage. Use of less preferred communities, which would allow regeneration of heavily used communities, could be achieved by manipulating availability of water sites and choice of grazing areas.