Habitat quality and range use of white-headed langurs in Fusui, China

The socioecology of white-headed langurs (Trachypithecus leucocephalus) was studied in Fusui Precious Animal Reserve, Guangxi, China, in 1997/1998. Habitat quality was classified according to the level of human disturbance. Plant species diversity increased with habitat quality. Important foods for the langurs occurred more in high-quality habitat. Home range size varied from 28 to 48 ha, and the home range area per individual decreased as habitat quality increased. Small polygynous langur groups had poorly defended ranges, but large groups defended their ranges intensively. Only harem males were involved in group defence, apparently competing for females by defending their habitat. High-quality habitat was more attractive to females; accordingly, group size increased significantly with habitat quality.     

白头叶猴与黑叶猴觅食行为的比较

开展近缘物种觅食行为比较对理解动物的行为可塑性及适应性具有重要意义。白头叶猴(Trachypithecus leucocephalus)和黑叶猴(T.francoisi)是近缘物种,体形大小相近,社会结构和栖息环境相似,是广西崇左白头叶猴国家级自然保护区喀斯特季节性雨林中邻域分布的灵长类。为了探索两个物种在喀斯特生境中是否有相似的觅食策略,我们于2012年1—12月采用瞬时扫描取样法对两种叶猴的觅食行为进行研究。结果表明,白头叶猴与黑叶猴在不同时段均为叶食性,树叶是两种叶猴各个时段主要食物,其中白头叶猴日均取食树叶77.0%±4.4%,黑叶猴日均取食68.9%±8.3%,两者对树叶的采食比例均没有显著的日时段差异(白头叶猴:χ²=6.602,df=11,P=0.830;黑叶猴:χ²=11.393,df=11,P=0.411)。两种叶猴的觅食行为都在猴群清晨离开夜宿石洞后和进入过夜山洞前的时段中频繁发生。白头叶猴在09:00—10:59和16:00—17:59出现觅食高峰,时间占比分别为41.7%和46.3%;黑叶猴同样在09:00—10:59...     

中国石山叶猴生态学研究进展

喀斯特石山是一类特殊环境,生存在喀斯特石山的动物形成特殊的行为机制以适应这一特殊的环境.石山叶猴是仅分布于喀斯特石山地区的珍稀濒危灵长类动物,属疣猴亚科乌叶猴属的一个种组,包括黑叶猴(Trachypithecus francoisi)、白头叶猴(T.leucocephalus)、德氏叶猴(T.delacouri)、金头...     

Food diversity and choice of white-headed langur in fragmented limestone hill habitat in Guangxi,China

We studied the diet and food choice of three groups of white-headed langurs (Trachypithecus leucocephalus) from July 2002 to June 2003 at Fusui Rare Animal Reserve, Guangxi, China. Data were collected from via focus group sampling, with continuous recording. A total of 109 plant species (including 19 unidentified species) were used as food by the white-headed langur. They spent 91.6% of total feeding time feeding on leaves, 4.2% on fruits and 3.3% on stems. Flowers and other food items accounted for only 0.3% and 0.6% of total feeding time, respectively. There were significant seasonal variations in the langurs’ diets with changes in the total number of species and the diversity of food species consumed. The langurs used significantly more plant species as food in the rainy season than in the dry season (36 species vs. 26.5 species). Dietary diversity was also significantly higher in the rainy season than in the dry season (2.6 vs. 2.4). No significant seasonal variation was found in the percentage of various plant parts in their monthly diets. Though the white-headed langur fed on many plant species, 11 species made up 84.9% of their diet. There were no significant correlations between the percentage of feeding time for main food plant species and their corresponding abundance in the habitat, content of water, crude protein, crude fiber and the ratio of crude protein to crude fiber. These results suggest that food choice of the white-headed langur is not influenced by their abundance and nutritional content.     

Habitat Quality and Activity Budgets of White-Headed Langurs in Fusui,China

Within a species, habitat quality may be a factor causing different activity budgets between populations. The habitat of white-headed langurs (Trachypithecus leucocephalus) has been seriously disturbed in Fusui Rare and Precious Animal Nature Reserve, China, where we carried out a study of their socioecology from September 1997 to September 1998. We collected data on langur activity budgets from the main population located in the central part of a group of limestone hills. We classified habitat quality into 4 grades according to the extent of human disturbance. We showed that the two main study groups of white-headed langurs spent on average 50% of time resting, 13% feeding, 18% moving (including foraging), 11% grooming, and 7% playing. Langur time budgets showed no significant seasonal change, but they differed among different sex-age classes. Infants and juveniles spent about 20.3% of time playing, whereas adults spent only 0.2% playing. The group in high quality habitat engaged less in feeding and more in playing than the group in low quality habitat did. Habitat quality influenced the playing time of young white-headed langurs and may be vital to their successful maturation.     

广西黑叶猴栖息地景观格局破碎化分析及其对种群的影响

黑叶猴(Trachypithecus francoisi)是仅分布于喀斯特石山生境的珍稀濒危灵长类动物。由于非法捕杀和人类活动干扰,其种群数量正在急剧减少。同时,随着森林砍伐和土地开垦的加速,其栖息地严重破碎化。因此,了解栖息地破碎化对黑叶猴种群的影响对于保护这一珍稀濒危物种具有重要意义。基于遥感影像、土地利用数据以及黑叶猴种群调查数据,通过Fragstats软件开展广西黑叶猴栖息地景观破碎化分析,并通过相关性和多元逐步回归分析,探讨了景观格局对广西黑叶猴种群数量的影响。结果表明：(1)广西黑叶猴栖息地呈现破碎化严峻、斑块形状复杂化、斑块团聚程度较弱且分散化的现象;栖息地以林地景观占据重要优势,但人为景观的干扰十分强烈;在不同地区中,生境破碎化程度、人为干扰强度以及景观配置均呈现不同的特征,其中扶绥地区人为干扰最为强烈,德保地区的景观块数破碎化程度较为严重,而龙州地区的人为干扰程度最小,其森林景观最为聚集。(2)蔓延度指数、平均斑块分维指数、林地面积、林地斑块大小、裸岩面积和裸岩面积比重等景观指数与黑叶猴种群数量有显著正向关系,Shannon多样性指数则是显著负向关系;而耕地面积、耕地...     

Factors Affecting the Ranging Behavior of White-headed Langurs (<Emphasis Type="Italic">Trachypithecus leucocephalus</Emphasis>)

Ranging behavior is an important aspect of animal behavior that researchers use to investigate ecological influences on individual behavior. We studied the influence of diet, water resources, and sleeping sites on the ranging behavior of 2 groups of white-headed langurs (Trachypithecus leucocephalus) in a limestone habitat at Fusui Nature Reserve, China, between August 2007 and July 2008. During the study period, the total home range sizes for the 2 focal groups were 23.8 ha and 33.8 ha, the mean daily path lengths were 491 m and 512 m, and leaves accounted for 83.4% and 91.0% of the diet, which are well within the range of variation reported for other Trachypithecus. One focal group traveled significantly longer distances in the rainy season months than in the dry season months. This variation may be related to the seasonal difference in food availability and diet. The langurs did not use their home ranges uniformly, and 50% of their activities occurred within 11% (group 1) and 20% (group 2) of their home ranges. The most heavily used quadrats in the home ranges were located near the most frequently used sleeping sites. Moreover, the core areas (>70% of location records) of both groups’ home ranges included ≥1 permanent water pool. The langurs ventured to these pools for drinking when surface water became scarce in the dry season. These results suggest that sleeping sites and water scarcity may be significant influences on the ranging behavior of white-headed langurs in limestone habitat.     

Marten space use and habitat selection in managed coniferous boreal forests of eastern Canada

Effects of habitat loss and fragmentation on the behavior of individual organisms may have direct consequences on population viability in altered forest ecosystems. The American marten (Martes americana) is a forest specialist considered as one of the most sensitive species to human-induced disturbances. As some studies have shown that martens cannot tolerate >30–40% clear-cuts within their home range, we investigated marten space use (home range size and overlap) and habitat selection in landscapes fragmented by 2 different patterns of timber harvesting in the black spruce boreal forest: dispersed-cut landscapes (10–80 ha cut-blocks) and clustered-cut landscapes (50–200 ha cut-blocks). We installed radio-collars on female martens and determined 20 winter home ranges (100% minimum convex polygons and 60–90% kernels) in dispersed-cut (n = 8) and clustered-cut (n = 12) landscapes. Home range size was not related to the proportion of clear-cuts (i.e., habitat loss), but rather to the proportion of mixedwood stands 70–120 years old. However, female body condition was correlated to habitat condition inside their home ranges (i.e., amount of residual forest and recent clear-cuts). At the home range scale, we determined that mixedwood forests were also among the most used forest stands and the least used were recent clear-cuts and forested bogs, using resource selection functions. At the landscape scale, home ranges included more mixedwood forests than random polygons and marten high activity zones were composed of more residual forest and less human-induced disturbances (clear-cuts, edges, and roads). These results suggest that mixedwood forests, which occupy approximately 10% of the study area, play a critical role for martens in this conifer-dominated boreal landscape. We recommend permanent retention or special management considerations for these isolated stands, as harvesting mixedwood often leads to forest composition conversion that would reduce the availability of this highly used habitat. © The Wildlife Society, 2013     

Effects of forest fragmentation on the lekking behavior of White-throated Manakins in Central Amazonia

Forest fragmentation can affect various aspects of population dynamics, but few investigators have assessed possible effects on the behavior of a species. Loss of habitat may limit population recruitment and abundance, which may alter breeding dynamics in forest remnants. We examined the lekking behavior of White-throated Manakins (Corapipo gutturalis) in a fragmented landscape to determine if forest fragmentation affected the spatial distribution of display courts and male behavior at courts. We captured and observed males at 19 courts located in 11 primary forests of different sizes in forest habitats of the Biological Dynamics of Forest Fragments Project area, an experimentally fragmented landscape located in the central Brazilian Amazon, and estimated their spatial distribution as the distance to the nearest court in the landscape. We quantified habitat loss using the proportion of forest cover surrounding courts and their distances to forest edges. No courts were detected in 1-ha forest fragments, suggesting direct effects from habitat loss following fragmentation that affected connectivity and thus recruitment and persistence of courts in the smallest fragments. The spatial distribution of display courts in forests larger than 10 ha remained unaltered, compared to display courts in continuous forests, but adult males were less numerous on courts with a higher percentage of forest cover and they displayed less on courts closer to forest edges. The spatial distribution of courts also contributed to variation in male social behavior, with more juvenile males present and adult males displaying at lower rates at more isolated courts. Although White-throated Manakins are locally common, the observed behavioral changes in response to habitat loss may affect their population dynamics. Our results show the importance of assessing behavioral changes in conservation programs and, in particular, of including biologically relevant measures of habitat loss in addressing its possible effects on species persistence in fragmented landscapes.     

Sleeping Cave Selection,Activity Pattern and Time Budget of White-Headed Langurs

We describe the activity patterns and time budgets of white-headed langurs that were confined to about 4 km² of Longlin habitat in Fusui County, Guangxi Province, China. Between February and December 1996, we observed 6 langur groups monthly via group focal sampling and continuously recording the behavior of a focal group. Our results indicate that the langur groups selected stone caves on cliffs as sleeping sites. The daily activity pattern outside caves had 8 stages: (1) leaving the cave in the early morning; (2) moving and resting; (3) morning feeding; (4) moving a long distance; (5) resting at noon; (6) afternoon feeding; (7) moving back to the cave, and (8) entering the cave. Over the year, langurs spent a daily average of about 11.5 h outside caves and about 12.5 h inside caves. Moving accounted for 7% (spring), 7% (summer-autumn) and 13% (winter) of the time budget, and langurs spent 9% (summer-autumn) and 14% (spring) to 20% (winter) of their time feeding. Resting accounted for 79% of the time budget in spring, 84% in summer-autumn, and 57% in winter. Sunbathing only occurred in winter and accounted for about 10% of the time budget. One-way ANOVA and multiple range tests demonstrated that time budgets differed significantly among seasons. Langurs spent significantly more time feeding and moving in winter than in spring and summer-autumn, but significantly less time resting in winter than in spring and summer-autumn.     

基于MaxEnt模式的白头叶猴栖息地评价——以广西崇左白头叶猴保护区为例

针对物种分布格局与其环境变量关系的研究,对于生态廊道规划与环境恢复研究具有重要意义.本文以白头叶猴(Trachypithecus leucocephalus)为研究对象,针对广西崇左白头叶猴国家级自然保护区51个白头叶猴分布点和11个环境变量数据,利用MaxEnt模型(maximum entropy modeling)...     

Are Limestone Hills a Refuge or Essential Habitat for White-Headed Langurs in Fusui,China?

We studied the ecology of white-headed langurs (Trachypithecus leucocephalus) in Fusui Precious Animal Reserve, Guangxi, China, in 1997/1998 and conducted surveys of them in 1996–1997 and 2003. We collected data on vegetation fragments and the activities of white-headed langurs at different levels on limestone hills. The langurs selected less fragmented habitats with less human disturbance. They spent ca. 60% of the day at lower levels of the hills during maintenance activities, including feeding. When humans were absent, the langurs even came to the ground. The hills themselves were used as a refuge from human disturbance but were not otherwise essential habitat. Results of this study have implications for improving conservation management for the langurs.     

Gene flow simulations demonstrate resistance of long-lived species to genetic erosion from habitat fragmentation

Habitat fragmentation restricts the movement of individuals across a landscape. In terrestrial and aquatic systems, barriers to movement can modify population and community dynamics at local or regional scales. This study contrasted life history traits related to lifespan with habitat fragmentation to determine impacts on species population genetic structure in the Neuse River Basin, USA. For this, we simulated gene flow among evenly-spaced populations in a river network and tracked individual and population genetics for 200 years. The modeled scenarios represent a full cross between five life history strategies and four riverscapes representing varying degrees of fragmentation. The five life history strategies include species (based on freshwater mussels) with average lifespans ranging from 10 to 50 years and age at maturity from 2 to 6 years. The movement landscapes included a (1) panmictic, (2) stepping-stone landscape allowing movement to only neighboring populations during each dispersal event, (3) partially-fragmented landscape divided by dams currently in the network, and (4) fully-fragmented landscape. Results suggest species with shorter lifespans have higher population genetic structure in fragmented landscapes than species with longer lifespans. Furthermore, species with shorter lifespans in highly fragmented landscapes may be harboring genetic degradation or decline as allele fixation and loss. Although anthropogenic fragmentation of many river systems is only 100–200 years old, the simulation indicates that species can respond genetically in that period of time. Additionally, the time frame of the simulation suggests that genetic impacts of habitat fragmentation in some species present in the Neuse River Basin may not yet be manifesting and restoration activities could be successful.     

Survival strategies of a frugivore,the sun bear,in a forest-oil palm landscape

As large areas of forest are lost throughout the tropics, prime habitat of many species decline and become fragmented. The island of Borneo is a prime example, with accelerated clearing of forests primarily for oil palm expansion. Borneo is recognized as an important stronghold for the conservation of the sun bear (Helarctos malayanus), but it is unclear how habitat reduction and fragmentation is affecting this frugivore. We used camera traps and sign surveys to understand patterns of sun bear habitat use in a matrix of fragmented forests and extensive oil palm development, which has existed as such for?>?15 years: the Lower Kinabatangan floodplain in Sabah, Malaysian Borneo. Within these small forest fragments, squeezed between a major river and oil palm plantations, bears exhibited selection for areas farther from human activity (plantations, river boat traffic, and buildings), and were rarely active during the day, demonstrating both spatial and temporal avoidance of potential human-related threats. They selected large trees to feed and rest, and also exploited adjacent plantations to feed on oil palm fruits. We conclude that even relatively small forest fragments (~?2000 ha) within large agricultural landscapes can be important for sun bears. Our research highlights the remarkable adaptations this species has employed to persist in a drastically modified landscape.     

Trait-specific response of ground beetles (Coleoptera: Carabidae) to forest fragmentation in the temperate region in Korea

The objective of this study was to examine the trait-specific response of ground beetles in terms of abundance, species richness, and composition for habitat fragmentation in temperate forests. In addition, we examined how different ecological groups and species of ground beetles responded to environmental variables. During middle May to early November in 2013, ground beetles were sampled using pitfall traps in 27 sites (18 patches and 9 continuous forests) in central Korea. A total of 51 species were identified from 17,845 ground beetles in the 27 study sites. Continuous forests had generally higher abundance and species richness of ground beetles than forest patches. Canonical correspondence analysis for ground beetles was significant, and the proportion of variance explained by environmental variables, such as patch size, elevation, organic matter (C), and soil moisture and pH, was 43.61%. In addition, species composition of ground beetles in continuous forests was grouped distinctively away from those in medium and small-sized patches. In conclusion, both small (1.1–9.6 ha) and medium patches (12.8–51.2 ha) were failed to preserve similar ground beetle biodiversity compared to continuous forests. However, our study revealed that medium-sized forest patches clearly had higher conservation value for forest specialist ground beetles than small-sized forest patches irrespective of forest type.     

Edge-related changes in tree communities in the understory of mesic temperate forest fragments of northern Japan

We have assessed the effects of habitat fragmentation on understory tree communities in mesic temperate forests of the Tokachi plain of northern Japan. Tree community composition was analyzed across 13 forest fragments of various sizes ranging from 0.30 to 8.51 ha. The community composition varied along the edge-to-interior gradient: there was a lower abundance of shade-tolerant shrubs in forest edges than in forest interiors, while saplings of dominant canopy trees and pioneer trees were more abundant near the edges. The edge influence extended approximately 56 m into the forest interiors. Even the interior area of small fragments were likely to be affected not only by the nearest edge but also by more distant edges. Consequently, most areas in fragments smaller than 2 ha were covered by these “edge-type” communities. These results indicate that it is of primary importance to conserve and restore forests with an area at least larger than several hectares to sustain forest-interior tree communities.     

Food Choice of White-Headed Langurs in Fusui,China

We studied the feeding ecology of white-headed langurs (Trachypithecus leucocephalus) from September 1997 to September 1998 in Fusui Rare and Precious Animal Reserve, SW Guangxi, China. We collected data in the central part of a group of limestone hills where the main population pool of langurs was located. The langurs fed on 50 plant species (belonging to 42 genera from 28 families) out of 164 species in the habitat (belonging to 112 genera from 48 families). Most of the food plant species were not common in the habitat. There are 16 important food species, including 6 key species. White-headed langurs were extremely folivorous, feeding mainly on young leaves (75% of total feeding records) of a broad range of less common plant species, which were in less disturbed areas. Thus, langur groups in high quality habitat had greater access to preferred foods, and the future of langurs in the Reserve may depend on immediate cessation of tree felling.     

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。     

Home Range Size and Habitat use by Cat Ba Langurs (<Emphasis Type="Italic">Trachypithecus poliocephalus</Emphasis>) in a Disturbed and Fragmented Habitat

Primate home range size and habitat use are affected by resource availability, which may change seasonally. Limestone langurs (Trachypithecus genus), including the Critically Endangered Cat Ba langur (Trachypithecus poliocephalus), live on limestone karst hills with shrubby and discontinuous vegetation. This study explores home range size and habitat use in relation to substrate, vegetation coverage, and hill type for Cat Ba langurs living on Cat Ba Island. We predicted that home range size would be similar to that of other limestone langurs and that as resources vary seasonally and across habitat types, habitat use would vary with season and behavior, with foraging concentrated on slopes, where food is plentiful. We collected 180 days of observational data on two reproductive groups (N?=?7 and N?=?10–13), taking GPS fixes of the group whenever they moved farther than the typical group spread to determine home ranges, and 10-min instantaneous scans to assess habitat use. The two groups had home ranges of 22 ha and 50 ha (0.32 and 0.20–0.26 individuals/ha respectively). Ranges for both groups were smaller in the dry season than the wet season, although we could not assess seasonal variation statistically. The langurs spent most scans on rocks, in sparsely vegetated areas, and on exposed slopes and steep cliffs; however they foraged primarily on gradually inclined slopes, especially in the dry season. These results suggest that conservation efforts should focus on protecting nutritionally important valleys and exposed slopes to ensure year-long access to food resources. It may, however, be difficult to balance human and nonhuman primate habitat use.     

Ranging behavior of the François’ langur (<Emphasis Type="Italic">Trachypithecus francoisi</Emphasis>) in the Fusui Nature Reserve,China

Data on activity budgets and ranging patterns were collected from March to December 2001 for one group of François’ langurs (Trachypithecus francoisi) inhabiting a forested part of the Fusui Nature Reserve, Guangxi province, China. Our results indicate that the total size of the home range of the study group during the study period was 19 ha. The majority of their activities (52%) occurred within a small area, 22%, of their home range, and was concentrated in or near quadrats containing their sleeping sites, which may reduce the time and energetic cost of travel. The extent of the ranging behavior varied between months, with the smallest, 7 ha, recorded in July and the largest, 13.5 ha, in November. There was no significant difference between seasons. The monthly mean daily path lengths varied from 341 to 577 m. The daily path lengths showed significant seasonal changes: the path lengths were longer during the dry season than in the rainy season, which may be related to the scarcity of preferred food resources during the dry season.