DIETS OF MAMMALIAN HERBIVORES IN AUSTRALIAN ARID, HILLY SHRUBLANDS - SEASONAL EFFECTS ON OVERLAP BETWEEN EUROS (HILL KANGAROOS), SHEEP AND FERAL GOATS, AND ON DIETARY NICHE BREADTHS AND ELECTIVITIES

The diets of euros or hill kangaroos (Macropus robustus), domestic she ep (Ovis aries) and feral goats (Capra hircus) in hilly, shrub rangela nd in southern Australia were examined in a 12-year study. Levels of d ietary overlap between these herbivores, their foraging in relation to resource availability, and the potential for competition in different conditions were also examined. The diet of euros was based around gra sses. In dry seasons some shrubs were also eaten but in severe drought grass formed more than 80% of their diet. While grass was important t o sheep in wetter conditions, they ate much shrub in dry conditions. F eral goats had broad diets but their preference for browse was high. I n drought, euros had only a modest dietary overlap with sheep and goat s. Data for dietary niche breadths and electivities pointed to only li mited competition between the herbivores. (C) 1996 Academic Press Limi ted