Reproductive Characters and Mating Behaviour of Wild Nomascus hainanus

We report for the first time the reproductive behaviors of Hainan gibbons (Nomascus hainanus), based on 29 mo of field observations. Receptive females initiated courtship displays. Copulatory patterns involved the male mounting dorsoventrally from above and behind. Multiple intromissions with thrusting were brief, lasting <10 s per copulation. We observed multiple copulations ≤4 times/d, but could not confirm multiple ejaculations. We also observed postconception proceptivity and copulations in sexually active females. We estimated the gestation period to be 136–173 d. Infants became independent at 1.5 yr, and the natal group could drive out maturing offspring at ca. 5.5 yr. The interbirth interval is ca. 24 mo. Our limited data also suggest that mating activities peak in the rainy season. The Hainan gibbons are polygynous, with a 1 male-2 females mating system. We hypothesize that suboptimal habitat quality and limited forest area may contribute to the current mating structure, but more work needs to be done over a longer period to understand better the sociosexual behaviors of this critically endangered species.     

Group harmony in gibbons: Comparison between white-handed gibbon (Hylobates lar) and siamang (H. syndactylus)

The siamang (Hylobates syndactylus) is exceptional among gibbons in that its area of distribution almost completely overlaps those of other gibbons, namely the white-handed gibbon (H. lar) and the agile gibbon (H. agilis) of the lar group. The siamang has almost twice the body weight of the gibbons of the lar group (ca. 11 kg vs. 5–6 kg), and it has been suggested that distinct ecological and behavioural differences exist between the siamang and its two sympatric species. The siamang has been claimed to differ from the white-handed gibbon “in the closer integration and greater harmony of group life” (Chivers, 1976, p. 132). However, few quantitative data exist to support this hypothesis. In the present study, intra-group interactions in captive family groups of white-handed gibbons and siamangs (two groups of each species) were recorded by focal-animal sampling. These data failed to show a consistent association between species and most of the behavioural patterns recorded, such as frequency of aggression, percentage of successful food transfer, frequency of social grooming bouts, and duration of social grooming/animal/hr. A significant difference was found for only two of the variables: Individual siamangs in this study showed longer grooming bout durations, and made fewer food transfer attempts than lar individuals. Only the first of these two differences is consistent with the hypothesis mentioned above, whereas the lower frequency of food transfer attempts in siamangs is the opposite of what should be expected under the hypothesis. On the other hand, two of these behavioural patterns showed a significant correlation with the parameters group size and individual age: Both individuals in larger groups and younger individuals tended to show shorter grooming bouts and a smaller proportion of successful food transfers. Our findings indicate that social cohesion within these gibbon groups may be much more flexible according to and depending on social or ecological influences and less rigidly linked to specific gibbon taxa than previously assumed. A considerably larger number of gibbon groups would have to be compared to provide reliable evidence for or against species-specific differences in group cohesion. Another finding of this study—a positive correlation between the frequency of aggression and grooming—is discussed in the light of the functional interpretations commonly attributed to allogrooming behaviour in primates.     

黑长臂猿（Hylobates concolor）对人类和非人类捕食者的回避行为

捕食和避免捕在动物生存和进化过程中起着重要作用,本文报道了我们自１９９０年３月至１９９２年元月观察黑长臂猿对人类和非人类捕食者的一系列反映,在遇到人类（观察者）后,据离观察者的远近和受惊程度不同,它们表现出５种回避方式,而在遇到非人类捕食者时,成年雌雄性一起将捕食者引开,以保护其后代个体免遭捕食。文中还对这些不同的行为方式进行了讨论。成年雄性是群体的主要保护者,成年雌性在群体保护中也起到重要的作用     

Construction, Characterization, and Chromosomal Mapping of a Fosmid Library of the White-Cheeked Gibbon (Nomascus leucogenys)

Gibbons have experienced extensive karyotype rearrangements during evolution and represent an ideal model for studying the underlying molecular mechanism of evolutionary chromosomal rearrangements. It is anticipated that the cloning and sequence characterization of evolutionary chromosomal breakpoints will provide vital insights into the molecular force that has driven such a radical karyotype reshuffle in gibbons. We constructed and characterized a high-quality fosmid li- brary of the white-cheeked gibbon (Nomascus leucogenys) containing 192,000 non- redundant clones with an average insert size of 38 kb and 2.5-fold genome coverage. By end sequencing of 100 randomly selected fosmid clones, we generated 196 se- quence tags for the library. These end-sequenced fosmid clones were then mapped onto the chromosomes of the white-cheeked gibbon by fluorescence in situ hy- bridization, and no spurious chimeric clone was detected. BLAST search against the human genome showed a good correlation between the number of hit clones and the number of chromosomes, an indication of unbiased chromosomal distribu- tion of the fosmid library. The chromosomal distribution of the mapped clones is also consistent with the BLAST search result against human and white-cheeked gibbon genomes. The fosmid library and the mapped clones will serve as a valu- able resource for further studying gibbons‘ chromosomal rearrangements and the underlying molecular mechanism as well as for comparative genomic study in the lesser apes.     

高黎贡山赧亢白眉长臂猿春季栖息地利用

2006年3月24日—5月6日,在高黎贡山赧亢片区共设置利用样地与可利用样地各30个,跟踪观察白眉长臂猿栖息地利用行为。定性因子分析表明,白眉长臂猿偏爱在东坡(Ei=0.344)活动,可能与其能提供避风的温暖微生境有关;偏爱栓皮栎(Ei=0.455)和拟樱叶柃(Ei=0.068)等乔木,可能是由于这些树种的树冠面积大,可为白眉长臂猿提供连续的移动路线和大的活动空间。定量因子分析表明,利用和可利用样地中共有12个因子(坡度,乔木和竹平均高度,乔木平均胸围,乔木和灌木盖度,乔木、竹和藤本密度,距水源、道路和草果地距离)存在显著差异,说明白眉长臂猿对栖境的空间结构具有高度的选择性。判别分析结果显示,坡度、乔木平均胸围、竹密度、距水源距离和乔木平均高度是判别利用和可利用样地的关键因子,即为影响其生境利用的主要因子,判别正确率为98.3%。作为树栖灵长类,具有一定基面积的连续乔木[高度(14.14±3.19)m,胸围(90.72±26.12)cm]树冠层是白眉长臂猿的适宜生境;较大的坡度(39.98±8.10°)减少了来自地面的干扰;而竹林是白眉长臂猿春季重要的取食地。     

东黑冠长臂猿鸣叫声谱分析

2007 年9 月至2009 年6 月,利用Sony TC - D5 Pro2 录音机、Sony C - 76 指向性话筒和Sony 录音磁带对广西邦亮自然保护区3 群东黑冠长臂猿的鸣叫进行了录音,对每群录音效果较好的5 个声音用Signal/ RTS 4.0 软件进行声谱分析。结果表明:东黑冠长臂猿叫声的频率较高,最高频率已经达到甚至超过了5 kHz;雄性的鸣叫声由起始音(boom)、简单的重复音节(aa notes)、调节前音节(pre-modulated note)和调节音句(modulated phrases)组成,雌性长臂猿一般只会发出一种固定而刻板的激动鸣叫,二者互相配合组成结构复杂的二重唱。通常,二重唱由成年雄性发起和结束,并占主导地位。同时,将东黑冠长臂猿二重唱的声谱结构与近缘种西黑冠长臂猿和海南长臂猿进行比较,结果显示雄性和雌性的叫声、以及二者配合发出的激动鸣叫序列在三者之间都有明显差异。因此,从声谱特征角度可以有效论证这三种长臂猿独立物种的分类地位。     

海南长臂猿栖息地结构分析

海南长臂猿主要栖息在热带沟谷雨林和山地雨林的高树上,对别种林型颇难适应。沟谷雨林和山地雨林植物群落垂直结构明显,乔木层次在3层以上,富巨型木质藤本和附生、寄生植物,为猿类创造了良好的食物和鸣寝条件。猿群喜欢在山体中部和中下部沟谷、坡壁林缘地段活动,罕去高海拔山巅或山脊林区。若避免过甚的人为干扰,在海南岛现有自然林条件下,猿群有可能得到发展。     

Individuality in the songs of wild agile gibbons (Hylobates agilis) of Peninsular Malaysia

Recordings were made and analyzed of the female dominated duet songs by eight adult pairs of wild agile gibbons from two sites in Peninsular Malaysia. A statistical analysis of their songs revealed that individuality occurred throughout the females' songs from both sites. Individuality in gibbon songs may allow singing individuals to more efficiently and effectively locate and identify neighboring nonmate conspecifics.     

被动声学监测技术在西黑冠长臂猿监测中的应用

近年来, 被动声学监测技术被广泛应用于陆生哺乳动物的监测, 它能以较低的价格和非侵入的方式在特定区域进行野生动物无人值守监测, 面临的主要问题是需要人工收回数据和后期数据分析整理较为困难。本研究设计了一套被动声学监测系统用于西黑冠长臂猿(Nomascus concolor)监测, 监测系统在野外由太阳能供电, 使用自研的指向性拾音器阵列采集鸣声数据, 并通过无线网桥实时传输数据至管护局办公楼的服务器进行存储, 通过后台的鸣声数据管理系统辅助研究人员识别鸣声和辨认鸣声来源方向, 简化数据采集和处理流程。该系统在哀牢山国家级自然保护区枇杷箐科研监听点对两个西黑冠长臂猿群体进行了351天的连续监测, 特点为: 系统运行长期稳定, 数据通过无线方式传输便捷高效且不受季节天气影响。指向性拾音器阵列能有效分辨长臂猿鸣声来源方向, 弥补了传统监测设备难以分辨鸣声方向的缺陷。该系统与现有人工监测方法相比在数据采集的持续性、连续性、完整度以及鸣声数据处理智能化和监测成本方面均具有一定优势, 符合西黑冠长臂猿持续长期监测需求, 未来可作为西黑冠长臂猿自动化监测的解决方案进行推广应用。     

Construction, Characterization, and Chromosomal Mapping of a Fosmid Library of the White-Cheeked Gibbon （Nomascus leucogenys）

Gibbons have experienced extensive karyotype rearrangements during evolution and represent an ideal model for studying the underlying molecular mechanism of evolutionary chromosomal rearrangements. It is anticipated that the cloning and sequence characterization of evolutionary chromosomal breakpoints will provide vital insights into the molecular force that has driven such a radical karyotype reshuffle in gibbons. We constructed and characterized a high-quality fosmid li- brary of the white-cheeked gibbon (Nomascus leucogenys) containing 192,000 non- redundant clones with an average insert size of 38 kb and 2.5-fold genome coverage. By end sequencing of 100 randomly selected fosmid clones, we generated 196 se- quence tags for the library. These end-sequenced fosmid clones were then mapped onto the chromosomes of the white-cheeked gibbon by fluorescence in situ hy- bridization, and no spurious chimeric clone was detected. BLAST search against the human genome showed a good correlation between the number of hit clones and the number of chromosomes, an indication of unbiased chromosomal distribu- tion of the fosmid library. The chromosomal distribution of the mapped clones is also consistent with the BLAST search result against human and white-cheeked gibbon genomes. The fosmid library and the mapped clones will serve as a valu- able resource for further studying gibbons' chromosomal rearrangements and the underlying molecular mechanism as well as for comparative genomic study in the lesser apes.