白掌长臂猿种

分布

白掌长臂猿分布在中国西南部、缅甸、老挝、泰国和整个马来半岛。印尼的苏门答腊岛上也有白掌长臂猿的踪迹。常见于热带森林。该物种的模式产地在马六甲。

特征

白掌长臂猿的毛色为黑色或褐色，手臂较长，手掌和脚掌部分为白色，脸部四周也长著一圈白毛。雄性和雌性的体型差别不大。

习性

白天活动，树栖性，栖息在雨林中，很少下地活动，而是通过长长的手臂在林闲穿梭。群居。食物主要是水果，也吃树叶、花蕾和昆虫。

繁衍

孕期为七至八个月，通常每胎一仔，幼白掌长臂猿一般要照料两年，八年完全成熟，野外平均寿命约为25年。

保护现状

作为濒危动物，白掌长臂猿面临多种威胁，主要包括人类的猎食、栖息地的减少等等。

中国国家重点保护动物等级：一级

中国濒危动物红皮书等级：濒危

分类

• 包括五个亚种：
• 马来白掌长臂猿 Hylobates lar lar
• 卡氏白掌长臂猿 Hylobates lar carpenteri
• 中部白掌长臂猿 Hylobates lar entelloides
• 苏门答腊白掌长臂猿 Hylobates lar vestitus

云南白掌长臂猿 Hylobates lar yunnanensis Ma et Wang于1986年命名。在中国大陆，分布于云南（南部）等地。该物种的模式产地在云南勐连,腊福。

The lar gibbon (Hylobates lar), also known as the white-handed gibbon, is an endangered primate in the gibbon family, Hylobatidae. It is one of the better-known gibbons and is often kept in captivity.

Taxonomy

• There are five subspecies of lar gibbon:
• Malaysian lar gibbon (H. l. lar)
• Carpenter's lar gibbon (H. l. carpenteri)
• Central lar gibbon (H. l. entelloides)
• Sumatran lar gibbon (H. l. vestitus)
• Yunnan lar gibbon (H. l. yunnanensis) (possibly extinct)

Physical description

The fur coloring of the lar gibbon varies from black and dark-brown to light-brown, sandy colors. The hands and feet are white-colored, likewise a ring of white hair surrounds the black face. Both males and females can be all color variants, and the sexes also hardly differ in size. Gibbons are true brachiators, propelling themselves through the forest by swinging under the branches using their arms. Reflecting this mode of locomotion, the white-handed gibbon has curved fingers, elongated hands, extremely long arms and relatively short legs, giving it an intermembral index of 129.7, one of the highest of the primates. As with all apes, the number of caudal vertebrae has been reduced drastically, resulting in the loss of a functional tail. Gibbons have tough, bony padding on their buttocks, known as the ischial callosities, or sitting pads.

Distribution and habitat

Lar gibbons have the greatest north-south range of any of the gibbon species. They are found in Indonesia, Laos, Malaysia, Myanmar and Thailand. Their range historically extended from southwest China to Thailand and Burma south to the whole Malay Peninsula in primary and secondary tropical rain forests. It is also present in the northwest portion of the island of Sumatra. In recent decades, especially, the continental range has been reduced and fragmented. Lar gibbons are likely extinct in China. However, if any populations persist, they would only be found in southwest Yunnan, their former range.

Lar gibbon are usually found in lowland dipterocarp forest, hill dipterocarp forest, and upper dipterocarp forest, including primary lowland and submontane rainforest, mixed deciduous bamboo forest, and seasonal evergreen forest.

Diet and dentition

The lar gibbon is considered frugivorous with fruit constituting 50% of its diet, but leaves (29%) are a substantial part, with insects (13%) and flowers (9%) forming the remainder. In the wild, lar gibbons will eat a large variety of foods, including figs and other small, sweet fruits, liana fruit, tree fruit and berries, as well as young leaves, buds and flowers, new shoots, vines, vine shoots, and insects, including mantids and wasps, and even birds' eggs. During the summer months, when figs and leaves are less available, insect consumption increases twenty-fold relative to the winter.

Its dental formula is 2.1.2.32.1.2.3, the generalized formula for Old World monkeys and apes (including humans). The dental arcade is U-shaped, and the mandible is thin and light.

Behavior

Lar gibbons are diurnal and arboreal, inhabiting rain forests. Lar gibbons are usually active for an average of 8.7 hours per day, leaving their sleeping sites right around sunrise and entering sleeping trees an average of 3.4 hours before sunset. On average, lar gibbons spend their days feeding (32.6%), resting (26.2%), traveling (24.2%), in social activities (11.3%), vocalizing (4.0%) and in intergroup encounters (1.9%), although actual proportions of activities can change significantly over the course of the year. They rarely come to the ground, instead using their long arms to brachiate through the trees. With their hooked hands, they can move swiftly with great momentum, swinging from the branches. Although they rarely come to the ground naturally, while there, they walk bipedally with arms raised above their heads for balance.

Conservation

Lar gibbons are threatened in various ways: they are sometimes hunted for their meat, sometimes a parent is killed to capture young animals for pets, but perhaps the most pervasive is the loss of habitat. Lar gibbon habitats are already threatened by forest clearance for the construction of roads, agriculture, ecotourism, domesticated cattle and elephants, forest fires, subsistence logging, illegal logging, new village settlement, and palm oil plantations.

Predation

Potential predators of lar gibbons in the Sikundur Monitoring Post include Sumatran tigers, Sunda clouded leopards, pythons (Python spp.) and grey-headed fish eagles.