Activity behavior of goitered gazelles in an arid environment

Abstract

The daily activity pattern in ruminants consists mainly of alternating foraging with bouts of resting, while other behaviors usually play a minor role in the daily activity budgets of ungulates most of the year. Interactions of both intrinsic and extrinsic factors force animals to adopt compromises to form optimal time proportions for foraging and resting to satisfy their daily energy demands. This paper considers the impact of ambient temperature, pasture conditions, body-size, and the effects of lactation and animal growth on the daily activities of goitered gazelles (Gazella subgutturosa). My study found: 1) temperature was the most significant factor leading to the greatest daily hour-to-hour variations in activity, as well as significant monthly changes in activity fluctuations; 2) seasonal improvement of forage conditions did not have a distinctive effect on daily activity; 3) the effect of body size, lactation and fawn growth also did not noticeably change activity fluctuations; but 4) factors related to hiding behavior had a significant impact on goitered gazelle activity. Though goitered gazelles are a sexually dimorphic species, they did not demonstrate any significant deviation between males and females in their daily activities in contrast to typical dimorphic ruminants. The goitered gazelles' hiding behavior may provide a possible explanation for this distinction, as other previously observed dimorphic ungulates were mainly species where fawns followed their mothers from birth. Among other influences, ambient temperature and features of their hiding behavior were the most significant factors influencing diurnal activity of goitered gazelles, while age and sex had a weaker impact on daily behaviors.

Keywords: Ambient temperature; Body-size effect; Daily activity; Dimorphic ungulates; Forage conditions; Hiding behavior.