Locomotion behavior of cao vit gibbon(Nomascus nasutus)living in karst forest in Bangliang Nature Reserve,Guangxi,China

The cao vit gibbon is a critically endangered species.Only approximately 110 individuals remain in degraded karst forest along the China-Vietnam border.Karst forest is unusual gibbon habitat.Currently,the canopy height of cao vit gibbon habitat is approximately 10 m.Research on the locomotor behavior of gibbons living in this particular forest type might provide important insight into locomotor stability and variability of gibbons.We used 5 min scan samples to record the locomotion mode,support use and canopy strata of gibbons in 3 groups for 2096 h between January 2008 and December 2009.Although cao vit gibbon habitat has a lower canopy in comparison to that of other forests inhabited by gibbons,cao vit gibbons displayed a similar overall locomotor pattern to other gibbon species(Symphalangus syndactylus,Hylobates lar and Hylobates agilis)in which brachiation dominate their locomotor behavior.Cao vit gibbons spent most of their time travelling on inclined branches(2-10 cm)in the middle stratum through the forest canopy.Adult females appear to more often employ safer modes of locomotion(bridging more often and brachiation less),while adult males choose riskier modes(leaping more and climbing less).As gibbons increased in body weight,as they grew from infant to adult,they tended to use larger supports.This research documented that locomotor behavior in Hylobatidae is strongly determined by anatomical characters,but cao vit gibbons also show the ability to use various supports,enabling them to survive in karst forest.

邦亮东黑冠长臂猿日食性与活动节律的季节性变化

日食性变化和活动节律是动物行为的重要方面,通过对日食性变化与活动节律的研究,可以了解食物、温度和光照时间等环境因素的变化对动物行为的影响,以及动物在行为上的应对策略。2009年1-12月,在广西靖西县邦亮东部黑冠长臂猿自治区级自然保护区内,采用瞬时扫描取样法对2群东黑冠长臂猿觅食行为和活动节律进行了研究。结果显示,东黑冠长臂猿的活动和食性在旱季和雨季都具有明显的节律。鸣叫只发生在12:00之前,但旱季的鸣叫时间偏晚。在日节律上,东黑冠长臂猿在离开过夜树后和进入过夜树前各有一个取食高峰,07:00喜欢取食果实和无花果,16:00也选择更多的果实,但无花果较少,13:00-15:00取食更多的叶和芽。在10:00-12:00,其用于休息和社会活动的时间增加。在雨季,东黑冠长臂猿以果实和无花果为主要食物,并且花大量时间觅食无脊椎动物;但在旱季,其食物以叶和芽为主。与之相适应,东黑冠长臂猿在旱季通过减少移动增加休息来节约能量开支和应对低温,同时它们增加取食的时间以获得等价的能量和营养。雨季时社会行为的比例明显高于旱季,而且其高峰出现在08:00-10:00,但旱季社会行为主要出现在11:00-14:00。在雨季东黑冠长臂猿没有出现休息高峰,相反在旱季10:00左右出现一个明显的休息高峰。上述行为节律体现了东黑冠长臂猿对环境季节性变化的良好适应,使其能够在寒冷并且退化的喀斯特森林中生存繁衍。