季节、性别和群体大小对鹅喉羚警戒行为的影响

Vigilance in Goitred gazelle(Gazella subgutturosa):effect of seasons,sexes and group size

动物通过集群降低个体警戒时间,从而增加采食等行为时间,这种现象被称为"群体效应"。除群体大小外,社会及环境因子如季节与性别也可能影响个体警戒水平。本文于2007年至2009年在新疆卡拉麦里山有蹄类野生动物保护区采用焦点动物取样法,通过测定鹅喉羚警戒行为比例、平均每次警戒持续时间及10min内警戒频率,研究了季节、性别及群体大小对鹅喉羚个体警戒水平的影响,并验证群体效应。结果表明:由于季节更替而产生的生物量的变化对鹅喉羚个体警戒水平无显著影响;在秋冬季除雄性外,鹅喉羚个体警戒水平均有随群体增大而降低的趋势,但这种趋势并不十分明显。性别则显著影响其警戒水平,夏季由于雌性羚羊处于哺乳期,因而其警戒水平显著高于雄性(P<0.05);受繁殖行为影响,冬季雄性比雌性警觉性更高(P>0.05);春秋季两性间警戒水平没有差异(P>0.05)。不同生理周期是导致鹅喉羚育幼期雌性及繁殖期雄性个体警戒水平发生显著变化的重要因子。

Animals receive benefits from their gregarious habit.As part of a group,individuals spend less time having to be vigilant,therefore more time on other behaviours,such as feeding.This phenomenon,called ＂group size effect＂,is considered the most dominant factor in an animal＇s demonstrated level of vigilance.However,in addition to group size,many other social and environmental factors also influence the degree of vigilance,including the season of the year and the sex of the individual.In order to examine vigilance behaviour of Goitred gazelles and to ascertain if a group size effect existed,the percentage of total time,vigilance duration,and vigilance frequency were recorded using the focal sampling method in the Kalamaili Mountain Nature Reserve during a two year period（2007-2009）.According to our results,we found that seasonal factors which lead to the changes of biomass weren＇t of substantial influence on a gazelle＇s level of vigilance.Gazelles decreased their vigilance level with increasing of group size in any season,though this trend was not so significant except for males in fall and winter.Sexes have significant influence on the vigilance behaviour of Goitred gazelle.Females were more vigilant in summer（P0.05）,because of the presence of young,and males were more vigilant in winter（P0.05）,because of their rut period.In spring and fall such differences between sexes were not significant（P0.05）.In comparison,the yearly breeding cycle was the most powerful factor,which significantly changed the degree of vigilance in females during birthing and males during rut.