Vigilance is recognized as the response to potential predation threats. Many factors influence vigilance behaviour, and the effect of group size has had a great deal of attention in recent years. The group size effect hypothesis proposes that there is a negative relationship between group size and vigilance, which has been proven ture for many birds and mammal species. However this relationship has not been investigated for a number of other species including the the Equus kiang. The E. kiang is the largest wild ass in the world, and endemic to the Tibetan Plateau. Previous studies have reported its distribution and reproduction, but information about their behaviour especially their daytime activity budgets is still very limited. Also unknown is if the distinctive habitat of the Tibetan Plateau makes their behaviour different from other Equidae species. So in this paper, we discuss our behavioural observations of the daytime activity budgets and the group size effect on vigilance for the E. kiang population in the Arjinshan National Nature Reserve, Xinjiang, China. The results indicate that group size has a significant effect on the vigilance levels: with an increase in group size, both the group scan level decreased and group scan frequency increased. Our results also showed that E. kiang spent most of their time feeding (51.41
± 2.74 %), followed by moving (22.49 ± 1.40 %), standing (19.62 ± 6.74 %), resting (18.41 ± 2.13 %), and other activities (8.64 ± 0.72 %). Their feeding behaviour showed three distinct activity peaks during the day: early morning (8:00-11:00), midday (14:30-15:30), and around sunset (18:00-19:30). During the peaks of activity, E. kiang spent most of their time feeding, and during the period of inactivity, E. kiang spent most of their time resting and standing. So the group size effect was supported for E. kiang by this study, and our results are consistent with research on other Equidae species.
In this paper, play behaviour of goitered gazelles is considered for the first time. Young gazelles demonstrated play activity most often, followed by adult males and sub-adults, then adult females. Locomotor play (running, jumping) was the most frequently observed play behaviour, while social play (fighting, sexual play) was noted considerably less often and mostly with males. Adult gazelles played mainly in May and gazelle young in June, and primarily in the evenings (19:00-20:00). Most acts of play lasted from several seconds to a half-minute. Young gazelles played often during their suckling period or, at least in the presence of their mothers. Adult females frequently became involved in their young’s play, while males played during grazing or butting. In describing goitered gazelle play patterns, we tested five hypotheses: practice-exercise, surplus energy, locomotor play ontogeny, different play types for specific stages of aging, and the social function of play. Our data for playful behaviour of goitered gazelles supported four of the five hypotheses, but contradicted the fourth listed above, which states, at least for Cuvier’s gazelles, that locomotor play appears and disappears earlier than social play. The cause of this difference in results may lie in the different conditions under which groups were observed or the different extent of the studies.