Effects of gender and group size on the time-activity budgets of adult breeding ostriches ( Struthio camelus) in a farming environment

Abstract

The behaviour of ostriches in a farming environment has not been described in any detail despite its importance in the development of efficient husbandry systems and in safeguarding welfare. This study describes the time budget of adult ostriches on a farm in Britain and examines the effect of time of day, gender and group size on behaviour. Adult ostriches ( N = 26) in breeding condition, maintained outdoors, were studied to determine their diurnal time-activity budget in the UK during the months of July and August. Males and females from pairs (1M 1F), trios (1M 2F), a small group (group 1: 3M 8F), and a large group (group 2: 7M 15F) were observed in nine time periods of 2 h duration between 04:00 and 22:00 h. Overall and diurnal time-activity budgets for males and females in the four group sizes were produced. The typical budget consisted of six predominant behaviours: standing, pacing (walking near enclosure boundaries), walking, sitting (head up), feeding (on concentrate feed), and foraging (from the pasture). There were 21 other behaviours recorded, including preening, aggression, sexual displays and mating, each of which occupied less than 5% of the time budget. The results between individuals were highly variable. In pairs and trios (pooled data), significant differences were found between males and females in foraging and feeding (females more than males) and pacing and walking (males more than females). These differences are considered to reflect the increased energy requirements of females during the reproductive cycle, and the territorial nature of males in the breeding season, respectively. No significant gender differences were found in groups 1 and 2. Temporal behaviour patterns were observed in feeding, foraging and sitting in all group sizes.