高黎贡山赧亢白眉长臂猿春季食物选择

2007年3月9日—4月28日,在高黎贡山赧亢跟踪观察白眉长臂猿(Hoolock hoolock)的春季食性及取食行为,将其行为分为食果、食果汁和食叶。采用瞬时扫描法记录白眉长臂猿的取食行为,取食的种类、部位和地点等。在其活动区域内,以取食树为中心设置20m×20m的利用样方和以随机方式设置同样大小的可利用样方各19个。在样方内收集与取食树及食物资源相关的6个因子的数据。统计食物种类和资源量、选择指数、取食点的选择性等。结果表明,赧亢白眉长臂猿春季取食的食物共10种,其中果实类植物3种,果汁类植物1种,嫩叶类植物6种。10种食物中,白眉长臂猿对印度木荷(Schima khasiana)的果实和缅甸木莲(Maglietia haokeri)的嫩叶呈弱选择,对其他8种食物资源均呈强选择。Mann-WhitneyU-检验结果表明,利用样方和可利用样方间的食物资源量及食物种类数均差异极显著,以利用样方的资源量大,每一样方食物种类较多。果实是赧亢白眉长臂猿春季的主要食物资源,而嫩叶是补充。呈强选择的食物并不一定是取食频次高的食物;反之,取食频次高的食物也不一定呈强选择。白眉长臂猿常选择易处理的果实和粗灰分含量少的嫩叶,且果实是它摄取水分的主要来源。白眉长臂猿通常选择食物资源和种类相对集中的区域取食,这可以减少动物因寻找食物所耗费的能量,同时获得多种食物,满足其生理对营养的需求。

Food Selection of Hoolock Gibbon (Hoolock hoolock) at Nankang, Mt. Gaoligong in Spring

The spring diet of Hoolock Gibbons (Hoolock hoolock) was observed by tracking them at Nankang of Mt. Gaoligong from March 3rd to April 14th, 2007. Their feeding behavior could be divided into eating fruit, drinking juice and eating leaves. Feeding behavior, food species, part of food to be eaten and feeding sites of the gibbons were recorded by scanning samples. In their active regions, nineteen used plots (20 m×20 m) around the feeding tree as well as the same number of available plots by random sample were set. Data of six factors involving feeding tree and food resource were collected from the plots. Food species and their quantity, selective index and selectivity of feeding spots were calculated. The results showed that in spring at Nankang the gibbons ate 10 botanic species, three of them for fruits, one for juice and six for young leaves. Among 10 food species, only fruits of Schima khasiana and young leaves of Maglietia haokeri were under selected and the other eight species were over selected. The result of a Mann-Whitney U test showed that the food resource and food species were significantly different between the used and available plots. There were more food resources and food species in the used plots. Fruits were the main food resource of the gibbons in spring at Nankang and young leaves were the supplement. The over selected food was not always at a high feeding frequency; in contrast, the food with a high feeding frequency was not always the over selected food resource. The gibbons often selected fruits that could be eaten easily and young leaves containing less ash. The fruit was also the main water resource. Hoolock Gibbons usually chose regions full in food resources and food species, so they could spend less energy looking for food, and at the same time choose from several species which satisfied their nutritional needs.