Herbivore diet in a semi-arid Eucalyptus populnea woodland. 2. Feral goats

Abstract

The diet of feral goats was recorded by direct observation in a shrub-dominated Eucalyptus populnea woodland between Nyngan and Bourke, N.S.W., on 7 sampling occasions over 2 years. Different nutritional opportunities were provided by the effects of rainfall on 4 contrasting grazing treatments. The goats foraged evenly over the paddocks and encountered most foods with the same frequency as they occurred. With unlimited quantities of forage available the goats spent 63% of their time grazing and only 28% browsing. Most browsing took place under dry conditions when pasture quality was low. When forage was in short supply the goats accepted some shrubs not normally eaten, and these plants died; other woody plants were consumed erratically or not at all. Acacia aneura was the only woody plant which was both palatable and resilient to goat browsing. Goats mostly ate the same plant species as sheep and with the same preference, but tended to eat more browse and less forbs than sheep in dry times. The browse consumed was principally the same as consumed by sheep, demonstrating sequential competition for dry-season fodder. Goats demonstrated a potential for overgrazing in dry times, indicating that stocking rates must be adjusted at such times to avoid pastures becoming extinct.