Trachypithecus Pileatus Research Articles

Mixed-species association and a record of a hybrid offspring between Trachypithecus pileatus and Trachypithecus phayrei in Bangladesh

The term mixed-species association has a broad range of definitions, from temporary foraging association to permanent group living. A mixed-species association mostly involves species from closely related taxa and is found in birds, mammals and fish. It ranges from passive association with little interaction to coordinated behavioural interactions between the group members of a mixed-species group. Mixed-species association can result in the production of hybrid offspring in the wild. In this study, we present, to the best of our knowledge, the first observational evidence of mixed-species association between the two threatened primate species Phayre’s langur (Trachypithecus pileatus) and capped langur (Trachypithecus phayrei), in fragmented forest patches of northeast Bangladesh. We also report a presumed hybrid offspring between these species. We conducted a short-term study from December 2021 to April 2022 in three forest patches based on information from eco-tourism guides. We confirmed the presence of three mixed-species troops; in two of the groups an adult male T. phayrei had permanently immigrated into a group of T. pileatus, and in the other one an adult male T. pileatus had permanently immigrated into a group of T. phayrei. A long-term detailed study is needed to elucidate the reasons for these mixed-species associations, their behavioural patterns, the fate of the presumed hybrid offspring, and to understand the genetic relatedness between the individuals.

Time Budget and Activity Pattern of Capped Langur (Trachypithecus pileatus) in Barail Wildlife Sanctuary, Assam, India

Time allocations for different activities of Capped langurs are depending on the environmental and habitatconditions. We observed time budgeting of Capped langurs for various activities on daily, monthly, seasonaland yearly basis from January 2017 to December 2019 in Barail Wildlife Sanctuary of Assam, India. Focalanimalsampling technique was used to record the diurnal active time spent by T. pileatus for differentactivities. From the observation it has been found that langur spent maximum time for resting (45%) followedby feeding (34%), locomotion (11%), grooming (5%) and others activity (5%). The amount of time allocatesfor different activities throughout the months was significantly different (F= 341.95, d. f = 4, P < 0.001).Time devoted to feeding was maximum in April (37%) and resting was 50% in August. In seasonal variation,it spent maximum (48%) time for resting in monsoon and lowest (41%) in winter. Highest (35%) feedingactivity was in winter and summer followed by lowest (32%) in monsoon and the seasonal variation of allthe activities was significantly varied. The diurnal time budget shows that it spent maximum (40.57%) timefor feeding in evening hours P < 0.001, while resting was highest (57.58%) between (10hrs-11hrs) andlowest (37.8%) in evening P < 0.001.

Seasonal variations in Home Range Size of Capped Langur (Trachypithecus pileatus) in a degraded habitat in Assam, India

A group of capped langurs, Trachypithecus pileatus comprising eight individuals was studied in Sri Surya Pahar, a degraded habitat in Goalpara district of Assam to record the seasonal variations in distance travelled, home range, and habitat utilization through direct observation supplemented by Geographical Information system (GIS). Scan sampling method was followed to record data on ranging behaviour. Seasonality in the home range size was evident and significant (P<0.01), it was 20 ha in winter, 17 ha in pre-monsoon, 17.75 ha in monsoon and 16.25 ha in retreating monsoon. The mean daily travel distance varied significantly (P<0.01), it was 375 m in retreating monsoon to 490 m in winter. The mean daily travel length was 439 m and the total annual home range size was 38.25 ha. The variation of home range size was correlated with the distribution and abundance of food resources. Home range size and daily travel distance showed significant seasonal variations. In both the cases the ranging patterns were longer during the winter season. This may be due to shortage of new leaves during winter, which is the preferred food item of capped langur. Spatial availability of the different food resources over different seasons may also be a reason for significant changes in ranging pattern during different seasons. The present data on home range size and ranging pattern of capped langur in degraded habitat could be useful for improvement of habitat and the conservation of this endangered species in Assam.

Attitudes and perceptions of people about the Capped Langur Trachypithecus pileatus (Mammalia: Primates: Cercopithecidae): a preliminary study in Barail Wildlife Sanctuary, India

Conservation of any species needs the support and cooperation of local people. In order to understand the attitudes and perceptions of the locals about the Capped Langur, the present study was carried out around Barail Wildlife Sanctuary in Assam. The study was carried out through a questionnaire, semi-structured interviews, and interaction with forest staff & local experts to assess the perception of present threats and conservation problems. A total of 400 respondents were interviewed during the study periods. The results reveal that a majority of respondents supported Capped Langur conservation. Habitat loss and fragmentation was considered a major threat (47%), followed by human exploitation (22%), developmental activities (17%), agricultural extension (8%), and hunting & teasing (6%). Knowledge concerning Capped Langurs and perceptions of threats varied considerably among respondents. Increased awareness among local people is suggested to motivate them towards conservation. Benefit sharing and promotion of value-added services through skill development could also be highly rewarding.

Population assessment of the endangered Western Hoolock Gibbon Hoolock hoolock Harlan, 1834 at Sheikh Jamal Inani National Park, Bangladesh, and conservation significance of this site for threatened wildlife species

Sheikh Jamal Inani National Park (Inani) is a wildlife habitat in Bangladesh located under the Cox’s Bazar South Forest Division, Cox’s Bazar. It constitutes significant habitat for the charismatic and globally ‘Endangered’ Western Hoolock Gibbon Hoolock hoolock in Bangladesh. Here, we show that Inani is a poorly-known gibbon habitat with a population of seven groups, comprising a total of 18 individuals. Among them, 77.8% were adults (males and females), and 11.1%, 5.6%, and 5.6% were sub-adults, juveniles, and infants, respectively, indicating low reproductive output. Five of seven groups had no offspring present in the group, and the mean group size of 2.57 individuals/group is low compared to other habitats in Bangladesh. Beside Western Hoolock Gibbon, Inani is home to many threatened wildlife species. The first record of the Slaty-backed Flycatcher Ficedula erithacus in Bangladesh occurred in Inani, adding this new species to the national bird checklist of Bangladesh. The presence of the globally ‘Endangered’ Asian Elephant Elephas maximus, Phayre’s Langur Trachypithecus phayrei, & Elongated Tortoise Indotestudo elongata and the globally ‘Vulnerable’ Northern Pig-tailed Macaque Macaca leonina, Capped Langur Trachypithecus pileatus, Indian Leopard Panthera pardus, & Asiatic Softshell Turtle Amyda cartilaginea highlight the importance of Inani as a conservation area in Bangladesh. The Western Hoolock Gibbon and other threatened wildlife of Inani are now on the verge of local extinction due to a sharp increase in forest resource extraction resulting from the recent influx of large numbers of Rohingya refugees from Myanmar, many of whom have settled around Inani. Through stakeholder interviews in the area, we have identified feasible and measurable conservation actions at Inani that are urgently needed to prevent further loss of wildlife and to protect this important gibbon habitat.

Feeding ecology of capped langur (Trachypithecus pileatus) in Sri Surya Pahar, a disturbed habitat in Goalpara District, Assam, India

A group of capped langurs, Trachypithecus pileatus comprising eight individuals was observed for feeding behavior in Sri Surya Pahar, an archaeological site of religious importance and degraded habitat, located about 12 km southeast of Goalpara town in Assam. The feeding ecology of the species was studied by recording the time spent feeding on different food plants and food categories during different seasons of the year. Scan sampling method was followed from dawn to dusk to record data on various aspects of feeding. Capped langurs spent 37.87% of their total active time in feeding during winter season, 34.12% in pre-monsoon, 26.60% in retreating monsoon, and 26.08% in monsoon season. Altogether 41 species of plants belonging to 24 families were utilized for feeding throughout the year. Capped langurs spent maximum time feeding on leaves. The time spent on feeding new leaves was highest during pre-monsoon season (63.70%) and lowest in winter (7.82%). While the time spent on feeding mature leaves was highest in winter (67.48%) and lowest in pre-monsoon season (2.31%). The time spent feeding flowers (20.78%) was maximum in winter and that on unripe fruits (20.79%) and petioles (9.24%) was maximum in pre-monsoon season. Flower buds, leaf buds, latex and insects were placed in ‘others’ category and were consumed in low quantity. From this study, a significant change was observed in the diet composition of Capped langurs during different seasons. Habitat degradation due to encroachment is the major threat to this endangered species in Sri Surya Pahar and its neighbouring areas. The study focused on the feeding ecology of capped langur in a degraded habitat. Therefore, the information generated from this study could be useful for evaluation and improving the quality of the habitat and formulating conservation and management action plan for capped langur.

Parasitic infection in captive wild mammals and birds in Bangabandhu Sheikh Mujib Safari Park, Cox’s Bazar, Bangladesh

We investigated the infection rate of gastrointestinal (GI) parasite eggs and premature stages from different wild animals and birds in Bangabandhu Sheikh Mujib Safari Park, Dulahazra, Cox’s Bazar. A total of 56 fecal samples were collected from 24 species during July to November 2012 using modified Stoll’s ova dilution technique. Coprology analysis revealed that the overall rate of parasitic infection was 78.6%, of which 51.8% were helminths and 35.7% protozoa. The identified parasites were Paramphistomum spp. (7.1%), Fasciola spp. (5.4%), strongyles (26.8%), Ascaris spp. (3.6%), Strongyloides spp. (7.1%), Dictyocaulus spp. (5.4%), Trichuris spp. (3.6%), Capillaria spp. (5.4%), Heterakis spp. (3.6%), and Balantidium coli (35.7%). Mixed infection (21.4%) was observed in nine animals, including co-infection with Balantidium coli and strongyles in Tiger Panthera tigris, Sambar Deer Rusa unicolor and Pig-tailed Macaque Macaca nemestrina, Strongyloides spp., Trichuris spp. and larvae of Dictyocaulus spp. in Capped Langur Trachypithecus pileatus, Balantidium coli and Capillaria spp. in Clouded Leopard Neofelis nebulosa, Fasciola spp. and Balantidium coli in Spotted Deer Axis axis, Ascaris spp. and strongyles in African Elephant Loxodonta africana, Strongyloides spp. and Heterakis spp. in Peafowl Pavo cristatus and Heterakis spp. and strongyles co-infection in Great Pied Hornbill Buceros bicornis. It is concluded that GI parasites were prevalent in this safari park. Further epidemiological investigation is necessary for controlling parasitic infection.

Feeding Behavior of Phayre’s Leaf Monkey (Trachypithecus phayrei) and Capped Langur (Trachypithecus pileatus) in Dampa Tiger Reserve, Mizoram

A study on feeding behavior of two primate species viz; Phayre’s leaf monkey (Trachypithecus phayrei, Blyth, 1847) and capped langur (Trachypithecus pileatus Blyth, 1843) was conducted during summer season (March–May, 2014) in Dampa Tiger Reserve (DTR), Mizoram, India. Study was carried out in the Terei range of forest reserve. A total of 87 plant species including bamboo were recorded in the area. Both species of primates (T. phayrei and T. pileatus) were studied for their food plant selection, diet composition, time budget for activities during day. Selection of trees to sleep at night was also observed. Capped langur selected 7 food plant species whereas Phayre’s leaf monkey selected 8 food plants. 40% of the plant species were common to both the primate species; however they showed a distinct variation in food plant preference. Phayre’s leaf monkey spent S 90% of feeding time on Musa ornata, Melacana baccifera and Dendrocalamus longispathus and S 80% Musa balbisiana, Gmelina arborea and Buetneria pilosa; an indication of preference for bamboo species and climbers. Capped langur spent feeding time S 90% on Ficus maclellendi and Ficus semicordata while other species were given comparatively less time. Both the species had consumed young leaves, flowers and fruits in their diet that constitute nearly 80% of the diet. Food items were drawn from different plants. The Phayre’s preferred Dendrocalamus longispathus, (98%) as sleeping site while the Capped langur selected Ficus benghalensis (90%) to sleep at night. Both the species are folivorous in nature but the selection of food plants, source of diet components and plants used to sleep at night were different that indicates that both species has distinct niche within the same habitat type; a very strong survival strategy.

Comparative activity pattern and feeding behaviour of Capped Langur (Trachypithecus pileatus) and Rhesus Macaque (Macaca mulatta) in Madhupur National Park of Bangladesh

Comparative activity pattern and feeding behaviour of Capped Langur (Trachypithecus pileatus) and Rhesus Macaque (Macaca mulatta) were studied in Madhupur National Park of Bangladesh from September 2015 to September 2016. Scan sampling method with 5 minutes interval was followed in the field. The Capped Langur spent 42% of the day time in feeding, 45% in resting, 6% in moving, 4% in playing, 2% in grooming and 1% in breeding, whereas the Rhesus Macaque spent 24% of the day time in feeding, 26% in resting, 30% in moving, 15% in playing, 4% in grooming and 1% in breeding. The Capped Langur spent comparatively more (7.25%) time in feeding than the Rhesus Macaque. Seasonal variation in feeding of the Capped Langur is more obvious than that in the Rhesus Macaque. Both species started their feeding activities early in the morning and stopped at late afternoon. Diet of the Capped Langur comprises of plant food (94%), animal food (3%), water (1%) and food offered by men (2%), and diet of the Rhesus Macaque comprises of plant food (79%), animal food (4%), soil (1%), water (2%) and food offered by men (14%). Both are mainly vegetarian but fed on varieties of food. It was found that the Capped Langur is primarily folivorous (48%) and the Rhesus Macaque is primarily frugivorous (55%). The Capped Langur fed on a total of 51 species of plant under 28 families and Rhesus Macaque fed on 38 species of plant under 18 families. The Capped Langur consumed more natural food (98%) than that of Rhesus Macaque (86%); the rest were food offered by men. The day ranges of Capped Langur and Rhesus Macaque were 400 metres and 550 metres, respectively. No notable conflict between Capped Langur and Rhesus Macaque was observed while feeding.Jahangirnagar University J. Biol. Sci. 6(1): 1-12, 2017 (June)

Late Pliocene Semnopithecus fossils from central Myanmar: rethinking of the evolutionary history of cercopithecid monkeys in Southeast Asia

We here describe a new fossil species of Asian colobine monkey, Semnopithecus gwebinensissp. nov. from the Late Pliocene Irrawaddy sediments of the Gwebin area in central Myanmar. Extant Semnopithecus (Hanuman langur) is a relatively large, terrestrial colobine monkey known as one of the most adaptable non-human primates. It is widely distributed, mainly in the Indian subcontinent, from Pakistan in the west to Bangladesh in the east. However, in Myanmar Semnopithecus is not distributed but Trachypihtecus is, which is the closest relative to Semnopithecus. It is presumed that extant Trachypithecus pileatus, which is considered to be a hybrid of Semnopithecus and Trachypithecus from molecular biological studies, appeared in the Early Pleistocene as the result of hybridisation between the two genera. On the other hand, no fossil specimens of other cercopithecid monkeys, such as Macaca, Trachypithecus or Rhinopithecus, all of which are commonly discovered from the Pleistocene cave sediments of South China, have been found from the Pliocene sediments in central Myanmar to date. The dissimilarity in the primate fauna between central Myanmar and South China suggests little faunal interchange between the two regions probably because of geographical barriers such as large rivers and high mountain ranges in the area.

Complete mitochondrial genome of the capped langur (Trachypithecus pileatus)

The complete mitochondrial sequence of the capped langur (Trachypithecus pileatus) has been determined using long amplification polymerase chain reaction (LA-PCR). The total sequence length is 16,526 bp and includes 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 D-loop locus. The base composition of H-strand is 31.9% A, 29.1% T, 26.2% C and 12.8% G, with an AT content of 55.3%. The arrangement of genes in T. pileatus is identical to that of other primate species. All genes are encoded on the heavy strand with the exception of ND6 and eight tRNA genes. The mitochondrial genome of T. pileatus presented here will contribute to a better understanding of the species’ population genetics, helping to protect its genetic diversity and resolve phylogenetic relationships within the family.

Distribution and Current Status of the Capped LangurTrachypithecus pileatusin India, and a Review of Geographic Variation in its Subspecies

In India, the capped langur (Trachypithecus pileatus) occurs in Assam, Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura. Elsewhere it is found in Bhutan, Bangladesh, northwestern Myanmar and a small area of Tibet, China. It is a forest-dwelling primate occurring in lowland, wet, evergreen rain forest to temperate forest. It ranges from the plains, 5 m above sea level, to 2,800 m in the Himalaya. Although it is the second most abundant primate of Assam, its populations are declining due to continuous destruction of its forests, and also hunting. Since the 1980s, one-third of the capped langur habitat in Assam has been lost because of tree felling and encroachment. It has been recorded in 53 protected areas in Northeast India. Of five subspecies recognized in the past (pileatus, durga, brahma, shortridgei and tenebricus) shortridgei is now considered to be a full species, and durga a junior synonym of pileatus. Trachypithecus p. pileatus occurs south of the Brahmaputra River; T. p. brahma and T. p. tenebricus occur north of the river. The lower reaches of the Jia-Bhoreli—Kameng River separate tenebricus (in the west) from brahma (in the east), but in the upper reaches in the higher Himalaya there is possible intergradation. Here, I report on hitherto unrecorded differences in facial hair patterns, (especially the cap) that differentiate the three subspecies. The langurs south of the Brahmaputra (pileatus) have shorter whiskers, and a distinct, conspicuous “army-cut hairstyle”-like cap, well separated from the ears. The subspecies to the north can be separated by the form of the cap—hairs radiating from the forehead to form a shaggy cap in tenebricus, and a less shaggy cap, resembling that of pileatus, but which extends to the ears in brahma. The distinguishing features are more dependable than overall color patterns, which vary individually and with age, sex, and season.

Role of Mother and Allomothers in Infant Independence in Capped Langur <I>Trachypithecus Pileatus</I>

We investigated the mother-infant relationship and allomothering in Capped Langur Trachypithecus pileatus in Pakhui Wildlife Sanctuary, Arunachal Pradesh, India, from July 2001 to June 2003, based on observations of five mother-infant pairs. Infants spent 75% of the time on ventro-ventral contact during the first three months, 71% of which was on nipples in the first month, which decreased gradually thereafter. The time of contact with mother varied significantly (p< 0.01) across the months. A significant negative correlation (Pearson: r = -0.963, p n=5 mother-infant pairs; 60 observations). Infants started straying away from mothers at around 16 days of age, and moved away as far as 3 m at the age of 30 days. The distance away from the mother increased up to 5 m at the age of 3 months, and they spent about 20% of their time away from the mother at the age of a year. Neonates spent 9.2% of the day with allomothers, and this increased to 25% for the next 15 days. It decreased gradually from the second month, and allomothering was not observed from the eighth month. The process of infant's independence started at the age of 6-8 months and was completed by 12 months, with infants spending 80% of their time away from the mother.

Observation of Grooming Behaviour in Wild Capped Langur Trachypithecus pileatus

The manual dexterity of primates allows them to use their hands to clean their skin and hairs as well as maintain a good social relationship with intra-group members. This behaviour is described as grooming. It is the most common affinitive behaviour among primates and may be directed to the self (Autogrooming) or with a intra-group member (Allogrooming or social grooming). Auto-grooming is often determined by the site accessibility, while social grooming is concentrated on parts inaccessible to the groomee. In this paper, we have recorded the grooming behaviour and patterns in capped langur (Trachypithecus pileatus) in Pakke Wildlife Sanctuary, Arunachal Pradesh, India. Focal-animal sampling technique was adopted for recording the grooming behaviour. The following behavioural observations in relation to time spent on grooming, grooming bouts and length, and grooming site preference are studied with the aim to assess the diurnal active time spent on grooming patterns of capped langurs. Of the 1683 hrs of observation, T. pileatus spent totally 60.95 hrs in grooming behaviours including 32.9 hrs (54%) for social grooming and 28.1 hrs (46%) for auto-grooming. A total of 1934 grooming bouts were recorded during the observation period. Of these, 58% bouts were for auto-grooming followed by 42% for social grooming. Maximum (15 min) grooming bout length was recorded in social grooming prior to copulation in compare to auto-grooming (8 min). Seven major body regions namely dorsal, ventral, lateral, ano-genital, face and head, tail and hind limbs were frequently observed to be groomed by capped langur. Of the total social grooming bouts (817), maximum (30%) was estimated on the dorsal side followed by 23% on ventral side, 21% on ano-genital region, 14% on lateral side, and 11% on face and head. Social grooming is adopted as tool to manipulate reproductive behaviour and to formulate survival strategies of the species.

Local and Landscape Correlates of Primate Distribution and Persistence in the Remnant Lowland Rainforests of the Upper Brahmaputra Valley, Northeastern India

Habitat fragmentation affects species distribution and abundance, and drives extinctions. Escalated tropical deforestation and fragmentation have confined many species populations to habitat remnants. How worthwhile is it to invest scarce resources in conserving habitat remnants within densely settled production landscapes? Are these fragments fated to lose species anyway? If not, do other ecological, anthropogenic, and species-related factors mitigate the effect of fragmentation and offer conservation opportunities? We evaluated, using generalized linear models in an information-theoretic framework, the effect of local- and landscape-scale factors on the richness, abundance, distribution, and local extinction of 6 primate species in 42 lowland tropical rainforest fragments of the Upper Brahmaputra Valley, northeastern India. On average, the forest fragments lost at least one species in the last 30 years but retained half their original species complement. Species richness declined as proportion of habitat lost increased but was not significantly affected by fragment size and isolation. The occurrence of western hoolock gibbon (Hoolock hoolock) and capped langur (Trachypithecus pileatus) in fragments was inversely related to their isolation and loss of habitat, respectively. Fragment area determined stump-tailed (Macaca arctoides) and northern pig-tailed macaque occurrence (Macaca leonina). Assamese macaque (Macaca assamensis) distribution was affected negatively by illegal tree felling, and rhesus macaque (Macaca mulatta) abundance increased as habitat heterogeneity increased. Primate extinction in a fragment was primarily governed by the extent of divergence in its food tree species richness from that in contiguous forests. We suggest the conservation value of these fragments is high because collectively they retained the entire original species pool and individually retained half of it, even a century after fragmentation. Given the extensive habitat and species loss, however, these fragments urgently require protection and active ecological restoration to sustain this rich primate assemblage.

Butterfly Species Richness and Diversity in the Trishna Wildlife Sanctuary in South Asia

Several wildlife sanctuaries in the world are home to the surviving populations of many endemic species. Trishna wildlife sanctuary in northeast India is protected by law, and is home to the last surviving populations of Asian bison (Bos gorus Smith), spectacle monkey (Trachypithecus phayrie Blyth), capped langur (Trachypithecus pileatus Blyth), slow loris (Nycticebus coucang Boddaert), wild cat (Felis chaus Schreber), and wild boars (Sus scrofa L.), among many other animals and plants. The sanctuary was explored for species richness and diversity of butterflies. A six-month-long study revealed the occurrence of 59 butterfly species that included 21 unique species and 9 species listed in the threatened category. The mixed moist deciduous mature forest of the sanctuary harbored greater species richness and species diversity (39 species under 31 genera) than other parts of the sanctuary, which is comprised of regenerated secondary mixed deciduous forest (37 species under 32 genera), degraded forests (32 species under 28 genera), and open grassland with patches of plantations and artificial lakes (24 species under 17 genera). The majority of these species showed a distribution range throughout the Indo-Malayan region and Australasia tropics, and eight species were distributed in the eastern parts of South Asia, including one species, Labadea martha (F.), which is distributed in the eastern Himalayas alone. Estimator Chao 2 provided the best-predicted value of species richness. The steep slope of the species accumulation curve suggested the occurrence of a large number of rare species, and a prolonged gentle slope suggested a higher species richness at a higher sample abundance. The species composition of vegetation-rich habitats showed high similarity in comparison to vegetation-poor habitats.

Status and Distribution of the Eastern Hoolock Gibbon (Hoolock leuconedys) in Mehao Wildlife Sanctuary, Arunachal Pradesh, India

A field survey was conducted in 2008–2009 in the Mehao Wildlife Sanctuary in Arunachal Pradesh, India, to investigate the status and distribution of the eastern hoolock gibbon there. The data were collected using line transects (trails covering all representative areas of the sanctuary) and by registering calling groups. We recorded 157 groups of gibbon in the sanctuary, of which 28 were directly sighted and 129 groups were registered by their calling. Of the 88 individuals seen, 61.4% were adults, 22.7% juveniles and 15.9% infants. Average group size was 3.14, with an adult sex ratio of 1:1. The survey also confirmed the presence of capped langur (Trachypithecus pileatus), Assamese macaque (Macaca assamensis), rhesus macaque (Macaca mulatta) and slow loris (Nycticebus bengalensis) in the sanctuary. We identified encroachment, jhum cultivation, horticulture, selective logging and inadequate infrastructure as being the major threats for the hoolock gibbon and other wildlife in the sanctuary. Although the gibbons were not hunted, hunting was evidently a threat to other wildlife in the sanctuary.

Primates of Bhutan and Observations of Hybrid Langurs

Six, possibly seven, species of non-human primates occur in Bhutan: slow loris (Nycticebus bengalensis), Assamese macaque (Macaca assamensis), Rhesus macaque (Macaca mulatto), Hanuman langur (Semnopithecus entellus), golden langur (Trachypithecus geei), and capped langur (Trachypithecus pileatus). A variant of the Assamese macaque, named Macaca munzala, has also been recorded there. Natural hybrids between golden and capped langur occur in an area in south-central Bhutan. The Assamese macaque is the most abundant and widespread primate, while slow loris is the least abundant, with a small range in Bhutan. Primates are not hunted for food in Bhutan, there are large areas of contiguous habitats for primates, and there is, besides, a good network of protected areas in the country. Overall, it would appear that primates have a secure future in Bhutan. The main conservation issues come from development, such as the construction of road networks and hydroelectric projects, grazing by domestic stock in some areas at high elevations, and people living in protected areas.

Population Status and Conservation of Capped Langurs (Trachypithecus pileatus) in and Around Pakke Wildlife Sanctuary, Arunachal Pradesh, India

A survey of the distribution and population status of the capped langur (Trachypithecus pileatus) was conducted in and around the Pakke Wildlife Sanctuary in Arunachal Pradesh, India. From 2001–2003, we surveyed ten selected localities, recording 26 groups and a total of 195 individuals. The data was obtained using line transect surveys and total count methods. Capped langurs were found in a number of different habitats: tropical semi-evergreen forest and moist deciduous forests. Of the 195 individuals registered, 14% were adult males, 52% adult females, 2% unidentified adults, 7% sub-adults, 11% juveniles and 15%) infants. The smallest group numbered 3, and the largest 13, with an average group size of 7.5 individuals. The male-female ratio was 1:3.6. The most common size class of the group was of 7–9 individuals.

Status and Diversity of Temple Primates in Northeast India

The northeastern region of India, comprising the seven states of Assam, Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura, has the highest primate diversity of the country. There are numerous populations of primates living in and around the temples of the region but none have been documented. Of the 17 primates found in India, 11 occur in the tropical and subtropical forests of these northeastern states. A primate survey was carried out from April 2003 to October 2003 in Assam, Arunachal Pradesh, Manipur, and Tripura to assess the status and diversity of temple primates. We found 16 temple sites in the region that support nonhuman primate populations of four species: Rhesus macaque (Macaca mulatto), Assamese macaque (Macaco, assamansis), golden langur (Trachypithecus geei), and capped langur (Trachypithecus pileatus). Loss of natural habitat and increased conflict between humans and nonhuman primates were found to be major threats for the temple primates of the region. The study suggests the need for a special conservation program with community initiatives to mitigate these problems. Key Words: Northeast India, temple, primates, habitat loss, human-primate conflict