云南无量山黑长臂猿对植物种子的传播作用

Seed dispersal by black crested gibbons (Nomascus concolor) in the Wuliang Mountains,Central Yunnan

2005年9月至2006年4月,对无量山一群黑长臂猿进行观察,研究黑长臂猿在植物种子传播中的作用。观察记录黑长臂猿一天的排便次数并收集粪便。通过直接观察和收集长臂猿粪便确定长臂猿取食的果实种类。以森林中采集的果实种子为对照标本,对粪便中的种子进行鉴定,并记录各种种子的数量,测量其长度、宽度和重量。结果表明观察期间黑长臂猿共取食31种果实,其中有1种在被取食时尚未成熟,另有2种果实的种子在取食后遭到破坏,还有1种植物的种子不能被长臂猿吞食而得不到传播,黑长臂猿可为27种植物传播种子。黑长臂猿个体平均每天排便2次,粪便的平均湿重为22.7g,每份粪便平均含有1种植物的种子;在不包含小种子(直径<3mm)的情况下,平均每份粪便中含有12粒种子。总的来说,黑长臂猿是有效的种子传播者。

Gibbons are the main frugivores in the forests of Southeast Asia, and consequently have long been considered to be good seed dispersers. The purpose of this study was to describe seed dispersal patterns of the black crested gibbon （ Nomascus concolor）. We studied one well habituated free-ranging gibbon group over 8 months in Wuliang Mountaia, Central Yunnan. When a gibbon defecated, the time and individual were noted and the feces were collected when possible. We tried to collect the whole feces, but it was very difficult because of the high canopy and the steep terrain. Seed species found in feces were identified by comparing them with seeds collected from trees in which gibbons fed. When entire defecations were obtained, we noted the species and counted the number of seeds ,larger than 3 mm . We also measured weight, length and width of each seed larger than 3 mm. We collected 60 entire feces ; mean weight of wet feces was 22.7 g. Each feces contained one seed species and 12 seeds larger than 3 mm. Individual gibbons defecated on average twice daily. Gibbons consumed seeds of 31 species and dispersed seeds of 27 of these. The largest seeds we documented in feces were of Symplocos ramosissima, averaging 21.2 mm long and 12.7 mm wide. Fruits with elongated seeds （high ratio of length/ width ） were more likely to be dispersed than round seeds （ low ratio of length/width ）.