Energy dynamics in the C4 species dominated montane subtropical grassland at Nilgiri Biosphere Reserve, the Western Ghats, India

The energy dynamics in Thiashola grassland, a montane subtropical vegetation in Nilgiri Biosphere Reserve, the Western Ghats, India is studied for a period of one year. The study revealed that the energy content in unit biomass of C₃ and C₄ species has not varied significantly. However, the C₄ species in total due to higher net primary production, entrapped 8.5 times greater solar energy (28.82 kcal/m²/day) than that of their C₃ counterparts. Of the total energy fixed, the C₃ and C₄ species, respectively channeled 4.07 kcal/m²/day and 13.3 kcal/m²/day to the aboveground standing live compartment. The transfer rate of energy to standing dead compartment from standing live part were 3.22 kcal/m²/day and 10.36 kcal/m²/day for C₃ and C₄ species, respectively and both the C₃ and C₄ together transferred 4.81 kcal/m²/day of energy from standing dead to litter compartment. The total dissipation of energy from the system is determined to be 4401.11 kcal/m²/yr and the surplus quantity of 38.37% of energy is accumulated in the aboveground parts of both C₃ and C₄ species which indicates the availability of substantial amount of energetic fodder to the wild herbivores in the Thiashola grassland.     

圈养白头叶猴春季昼夜活动节律

2008 年3 ～5 月,采用瞬时扫描法,对上海动物园5 只白头叶猴的行为进行24 h 昼夜连续观察。结果表明:春季圈养白头叶猴一天的活动起于06∶ 00 左右,结束于18∶ 00 或18∶ 30。白天白头叶猴的主要行为为休息、取食和移动,平均频次依次是13.79 次、4.75 次和2.18 次。夜间的主要行为为休息、移动和抓挠,平均频次依次是22.13 次、0.43 次和0.26 次。不同个体昼夜活动节律差异很大。其中,移动、理毛、玩耍和其它行为的差异显著。夜间无理毛和玩耍行为,移动行为在夜间21∶ 00, 00 ∶ 30, 03∶00 和04∶ 30 出现高峰。在22∶ 30, 01∶ 00, 02∶ 00, 03∶ 30, 04∶ 30 和05∶30 则出现抓挠高峰。这预示白头叶猴夜间休息时处于一个“轻睡眠”状态。同时,雌雄白头叶猴昼夜移动行为差异显著。     

Influence of two different diets on fluid and particle retention time Javan langur (Trachypithecus auratus auratus)

In captivity, langurs (foregut fermenting primates) often suffer from digestive disorders, and in particular display soft stools on diets with a high proportion of fruits, vegetables, and grain products. In this study, we tested whether the improvement in feces consistency expected after an omission of vegetables from a conventional diet was also accompanied by a change in the excretion pattern as measured by the mean retention time (MRT). Two adult Javan langurs were kept together and offered a conventional diet of pellets, browse, vegetables, or a diet consisting of pellets and browse only. MRT were measured with cobalt-EDTA as the fluid and chromium oxide as the particle marker before, during, and after the test diet, collecting the feces of both animals together. MRTs of fluids and particles were longer (47/49 h) on the test diet as compared to the usual diet (42/43 h). Feces consistency improved during the test period. The test period was marked by an increased fiber intake; however, on the conventional diet, dietary water intake exceeded the calculated water flux for these animals distinctively, due to the high proportion of vegetables. Therefore, it cannot be decided whether the increase of fiber level alone or also a reduction of the excessive water intake was responsible for the changes observed. Comparing the results of this study to other studies on ingesta retention in foregut fermenting primates, no correlation between the body mass of the animals and the MRTs measured is evident, which is in accordance with observations in other groups of foregut fermenters.     

Resource partitioning in sympatric langurs and macaques in tropical rainforests of the central Western Ghats, south India

In a competitive sympatric association, coexisting species may try to reduce interspecific interactions as well as competition for similar resources by several ecological and behavioral practices. We studied resource utilization of three sympatric primate species namely, lion-tailed macaques (Macaca silenus), bonnet macaques (M. radiata) and Hanuman langurs (Semnopithecus entellus) in a tropical rainforest of the central Western Ghats, south India. We studied resource use, tree-height use, foraging height, substrate use when consuming animal prey and interspecific interactions. The results revealed that across the year, there was very limited niche overlap in diet between each species-pair. Each primate species largely depended on different plant species or different plant parts and phenophases from shared plant species. Primate species used different heights for foraging, and the two macaque species searched different substrates when foraging on animal prey. We also recorded season-wise resource abundance for the resources shared by these three primate species. While there was low dietary overlap during the dry season (a period of relatively low resource abundance), there was high dietary overlap between the two macaque species during the wet season (a period of high resource abundance for the shared resources). We observed only a few interspecific interactions. None of these were agonistic, even during the period of high niche overlap. This suggests that the sympatric primate species in this region are characterized by little or no contest competition. Unlike in some other regions of the Western Ghats, the lack of interspecific feeding competition appears to allow these primates, especially the macaques, to remain sympatric year-round.     

弄岗黑叶猴的日活动类型和活动时间分配

2005年10月-2006年9月,用瞬时扫描法对广西弄岗自然保护区内的一群黑叶猴(Trachypithecusfran oisi)的日活动节律和活动时间分配进行研究。结果表明:黑叶猴日活动中出现2个觅食高峰和1个休息高峰。觅食高峰分别出现在7:00-9:00和16:00-18:00;休息高峰出现在10:00-14:00。黑叶猴日活动节律表现出明显的季节性变化,表现为旱季上午的觅食高峰被推迟了1h,且觅食时间长于雨季;旱季下午的觅食活动提前1h结束。猴群在雨季较早进入休息高峰,而且中午休息时很少有移动或零星觅食。研究期间,猴群用于休息的时间平均占日活动时间分配的51.99%,移动占20.25%,觅食占18.61%,理毛占7.61%,玩耍占1.20%,其它行为(包括打斗、交配等)仅占0.14%。活动时间分配有明显的季节性差异,主要表现为:与雨季相比,黑叶猴在旱季花费更多的时间用于觅食和移动,而相应地减少用于休息的时间。活动时间分配在不同年龄和性别的个体之间也存在显著差异,表现为成年个体花费更多的时间用于休息和觅食,未成年个体则花费更多的时间用于移动和玩耍;雌性个体比雄性个体花费更多的时间用于理毛。     

栖息地质量对黑叶猴活动时间分配的影响

2005 年9 月至2006 年8 月,在广西弄岗国家级自然保护区和扶绥珍贵动物保护区各选择一群黑叶猴作为研究对象,采用瞬时扫描取样法收集相关的行为数据。通过比较两个地理种群活动时间分配的数据来探讨栖息地质量对黑叶猴活动时间分配的影响。结果表明:生活在低质量栖息生境的黑叶猴猴群较生活在高质量栖息生境的猴群花费更多的时间休息和觅食,而用于移动和社会活动的时间相应减少。分析表明,栖息地质量的差异所造成的食物可获得性以及食物组成的差异可能是影响黑叶猴群活动时间分配差异的重要因素。虽然不同活动的峰值在日活动节律中出现的时间存在差异,但总的日活动节律在不同地理种群中表现出相同的趋势,即早晨和下午出现两个明显的觅食高峰,而中午则是长时间的休息;移动的高峰通常发生在觅食高峰之前。     

Monandrous social organization of pigtailed langurs ( Simias concolor ) in the Pagai Islands, Indonesia

Between June 1986 and October 1992, in 3 periods totaling 12 months, we studied social organization of pigtailed langurs (Simias concolor)in the Pagai Islands, Indonesia. With one possible exception, all of 20 family groups contained only 1 adult male each. Nine of them contained only 1 adult female,and 11 contained ≥2 adult females. Mean group size is 4.1 individuals. Home ranges varied from 7 to 20 ha, and population density averages 21 animals/km ² . Simias concoloris sexually dimorphic⤖n a museum sample males average 29% heavier than females, and their canine teeth are on average nearly twice the length of female canines. Combined data from several studies indicate that 60% of S. concolorgroups contain an adult pair plus young,and 40% are multifemale groupings. We sggest that any 1-male mating system that comprises a mixture of 1-female and multifemale groups in the same population should be termed monandry.     

Observations on parturition and allomothering in wild capped langur (Trachypithecus pileatus)

A birth during the day by a capped langur (Trachypithecus pileatus Blyth, 1843) was recorded at Pakhui Wildlife Sanctuary, Arunachal Pradesh, India. The birth took 43 min. Allomothering was observed 3 h after the birth. An average of 9% of daily active time was shared by four allomothers (three adults, one subadult) during the first 15 days of the infants life. Total time allomothering was proportional to the age of the allomothers (241 min for oldest; 214 min for youngest).     

广西扶绥黑叶猴活动节律和日活动时间分配

2002 年8 月至2003 年7 月,对生活在完全被周围农田隔离的石山中的一群黑叶猴的昼夜活动节律和日活动时间分配进行研究。采用以群为单位的焦点动物观察法和连续记录法,每月对猴群连续10 d 跟踪观察。结果表明:3 月至10 月,黑叶猴的昼夜活动节律由8 个环节组成,11 月至2 月由9 个环节组成,移动、觅食和休息在活动节律中重复出现,晒太阳仅出现在11 月至翌年2 月。休息占黑叶猴日活动时间的比例最大,其次是觅食、移动、晒太阳和理毛。黑叶猴的日活动时间分配具有明显的月变化规律,相关性分析表明,环境温度、栖息地的食物丰富度和光照强度是影响黑叶猴日活动时间分配的主要因素。进一步分析认为,黑叶猴的活动时间分配体现了叶食性灵长类的特点,更体现了黑叶猴对北热带喀斯特石山环境的适应特点。