Antipredator strategies and social factors may influence vigilance behaviour in herbivores. Vigilance can differ between sex/age classes, but information is contradictory in the existing literature. We investigated sex/age differences of vigilance in fallow deer Dama dama, in a Mediterranean area. Females (> 1 year old) showed a lower proportion of time foraging and a greater alertness rate than males (≥ 1 years old). Decrease of vigilance with increasing group size was observed for females and adult males, but not for young and subadult males, suggesting that group-size effects on vigilance were not consistent across individuals of different sex/age classes. Most likely, females tended to reduce the predation risk for their offspring through a comparatively greater duration and frequency of vigilance. Young/subadult males showed a greater alertness than adult males, which may depend on intraspecific competition in larger groups. Both antipredator and social factors could explain sex/age differences of vigilance in fallow deer.

中文翻译：

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食草动物在觅食，警惕和警觉方面的性别/年龄差异

反掠食者的策略和社会因素可能会影响食草动物的警惕行为。性别/年龄段之间的警惕性可能会有所不同，但是现有文献中的信息是矛盾的。我们调查了小鹿达马黄雀的警惕性/年龄差异，在地中海地区。与男性（≥1岁）相比，女性（> 1岁）的觅食时间比例较低，机敏率更高。女性和成年男性观察到警惕性随着组规模的增加而降低，而男性和成年男性则未观察到，这表明不同性别/年龄组的个体对警惕性的组规模效应不一致。雌性很可能通过相对较长的警戒时间和频率来降低​​后代的捕食风险。年轻/亚成年男性比成年男性表现出更高的警觉性，这可能取决于较大群体的种内竞争。反掠食者和社会因素都可以解释小鹿警惕的性别/年龄差异。