Foraging behaviour of goats and sheep in the Caatinga of Brazil.
The seasonal feeding patterns of sheep and goats was quantified by estimating the time spent per feeding station, and the proportion of foraging time spent by goats and sheep in the bipedal stance and feeding at several heights in the quadrupedal stance. The animals grazed caatinga vegetation, a mix of deciduous trees with an annual herbaceous understorey that is strongly influenced by wet and dry seasons. Goats and sheep grazed in different layers of vegetation. Sheep spent 36% of their foraging time grazing at or near ground level, compared with 18% for goats (P <0.05). Goats stood on their hind legs for 1% of their foraging time in the dry season and for 8% in the wet season. There was no nutritional advantage to goats in using a bipedal stance, compared with quadrupedally grazing sheep, because in the season of nutritional stress (the dry season) there was little or no forage in the bipedal foraging zone.