Khao Yai National Park Research Articles

Effects of social status and stress on patterns of gastrointestinal parasitism in wild white‐handed gibbons (Hylobates lar)

Although gibbons (family Hylobatidae) are typically monogamous, polyandrous groups occur regularly. Stress associated with elevated intragroup competition among males in polyandrous groups may increase susceptibility to infectious disease. To better understand this interplay, as well as to provide the first comprehensive assessment of parasitism in free-ranging gibbons, we characterized the richness of gastrointestinal parasites and examined their prevalence in males from 14 groups (10 pair-living, 4 multi-male) of white-handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand. From September 2008 to May 2009, 324 fecal samples were collected from 23 individually recognizable male gibbons and screened for gastrointestinal helminths and protozoa after isolation via fecal floatation, sedimentation, and immunofluorescent antibody detection. A total of 10 parasite species recovered, including seven nematodes, two protozoans, and one trematode. Parasite richness and species-specific prevalence were examined relative to social organization (pair-living vs. multi-male), male status (primary vs. secondary), age (subadult, adult, senior), fecal glucocorticoid levels, and time of the year. No relationship was found between parasite richness and sociodemographic or physiological factors. Similarly, prevalence of infection with parasite species was not associated with the majority of sociodemographic factors; however, Ternidens sp. and Balantidium coli varied seasonally and Trichuris sp. decreased with increasing age. Moreover, observational data suggest that competition is low in this gibbon population, and our findings are consistent with those observations in that cooperative defense may offset stress and reduce susceptibility to infection.

Frugivory and Seed Dispersal by Northern Pigtailed Macaques (Macaca leonina), in Thailand

Tropical rain forest conservation requires a good understanding of plant–animal interactions. Seed dispersal provides a means for plant seeds to escape competition and density-dependent seed predators and pathogens and to colonize new habitats. This makes the role and effectiveness of frugivorous species in the seed dispersal process an important topic. Northern pigtailed macaques (Macaca leonina) may be effective seed dispersers because they have a diverse diet and process seeds in several ways (swallowing, spitting out, or dropping them). To investigate the seed dispersal effectiveness of a habituated group of pigtailed macaques in Khao Yai National Park, Thailand, we examined seed dispersal quantity (number of fruit species eaten, proportion in the diet, number of feces containing seeds, and number of seeds processed) and quality (processing methods used, seed viability and germination success, habitat type and distance from parent tree for the deposited seeds, and dispersal patterns) via focal and scan sampling, seed collection, and germination tests. We found thousands of seeds per feces, including seeds up to 58 mm in length and from 88 fruit species. Importantly, the macaques dispersed seeds from primary to secondary forests, via swallowing, spitting, and dropping. Of 21 species, the effect of swallowing and spitting was positive for two species (i.e., processed seeds had a higher % germination and % viability than control seeds), neutral for 13 species (no difference in % germination or viability), and negative (processed seeds had lower % germination and viability) for five species. For the final species, the effect was neutral for spat-out seeds but negative for swallowed seeds. We conclude that macaques are effective seed dispersers in both quantitative and qualitative terms and that they are of potential importance for tropical rain forest regeneration.

Climate change and tourism: Impacts and responses. A case study of Khaoyai National Park

The problem of climate change has discernible impacts on human living on a wide scale. This study explores the effect of climate change on changes in tourism trends at Khaoyai National Park. In 2010, Khaoyai National Park had a recreational and tourism value of approximately 2.8–3.7billion baht ($93–$123million) per year. Temperature and climate changes are considered by many tourists to be significant factors influencing whether they visit the park. This study discovers that increases in temperature and precipitation each year have adversely affected the number of tourists to the site, reducing the number of visits by 22%. The total recreational value of the park is estimated to be 1.8–2.6billion baht ($60–$86million) per year, approximately 30–35% less than in the baseline case.

Density estimation of Asian bears using photographic capture–recapture sampling based on chest marks

Assessing the conservation status of species of concern is greatly aided by unbiased estimates of population size. Population size is one of the primary parameters determining urgency of conservation action, and it provides baseline data against which to measure progress toward recovery. Asiatic black bears (Ursus thibetanus) and sun bears (Helarctos malayanus) are vulnerable to extinction, but no statistically rigorous population density estimates exist for wild bears of either species. We used a camera-based approach to estimate density of these sympatric bear species. First, we tested a technique to photograph bear chest marks using 3 camera traps mounted on trees facing each other in a triangular arrangement with bait in the center. Second, we developed criteria to identify individual sun bears and black bears based on chest-mark patterns and tested the level of congruence among 5 independent observers using a set of 234 photographs. Finally, we camera-trapped wild bears at 2 study areas (Khlong E-Tow, 33 km 2 , and Khlong Samor-Pun, 40 km 2 ) in Khao Yai National Park, Thailand, and used chest marks to identify individual bears and thereby derive capture histories for bears of each species. Average congruence among observers' identifications of individual bears was 78.4% for black bear and 92.9% for sun bear across sites. At Khlong E-Tow, we recorded 13 black bears (8 M, 4 F, 1 unknown sex) and 8 sun bears (1 M, 5 F, 2 unknown sex). At Khlong Samor-Pun, we recorded 10 black bears (6 M, 4 F) and 6 sun bears (4 M, 2 F). We used a spatially explicit capture-recapture method, resulting in density estimates of 8.0 (SE 5 3.04) and 5.8 (SE 5 2.31) black bears per 100 km 2 and 5.9 (SE 5 3.07) and 4.3 (SE 5 2.32) sun bears per 100 km 2 for each study area, respectively. Our camera trap design and chest-mark identification criteria can be used to estimate density of sun bears and black bears, enhancing knowledge of the conservation status of these threatened and little-known bear species.

Seasonal cambial activity of five tropical tree species in central Thailand

The seasonal cambial activity of five tropical tree species was investigated at Khao Yai National Park. The species studied were Tetrameles nudiflora, Magnolia baillonii, Canarium euphyllum Kur, Toona ciliata, and Spondias axillaris. Cambial activity was quantified by counting layers of undifferentiated cells in the cambium zone from wood anatomical micro sections prepared from wood samples collected in monthly intervals from July 2010 to June 2011. The relationship between cambial activity and climatic factors was investigated by using Pearson’s correlation. The growth dynamics of five studied species differed considerably. The cambium of Tetrameles nudiflora and Magnolia baillonii was most active when rainfall reached its maximum amount in June (mid rainy season), whereas the cambium of Canarium euphyllum, Toona ciliata, and Spondias axillaris was most active in March during the transition from the dry to the wet season.

Octaviania violascens: a new sequestrate bolete from Thailand

Octaviania violascens sp. nov. is proposed for a new sequestrate bolete from Khao Yai National Park, Nakhon Ratchasima Province, Thailand. A comprehensive description and illustrations are provided.

Molecular evidence for the introgression between Hylobates lar and H. pileatus in the wild

Inter-specific hybrid zones for Hylobates gibbons are known in Southeast Asia. Among these, one hybrid zone between Hylobates lar and H. pileatus is located in Khao Yai National Park, Thailand. To find molecular evidence for the natural hybridization of the gibbons in this region, we studied mitochondrial DNA (mtDNA) of 68 gibbons of the H. lar phenotype living adjacent to the hybrid zone. Nucleotide sequencing of a fragment of mtDNA spanning hyper variable segment I showed that nine gibbons had an mtDNA haplotype of H. pileatus, and that seven of these nine gibbons belonged to a single maternal lineage over three generations. It is thus confirmed that introgression between H. lar and H. pileatus exists and the initial hybridization took place ages ago.

Sociodemographic Correlates of Fecal Androgen Levels in Wild Male White-Handed Gibbons (Hylobates lar)

Despite the central role of testosterone in influencing many aspects of the male life cycle, information on the influence of social and behavioral factors associated with androgen output is available for only a few primate species, mainly those living in multimale–multifemale societies. We collected 322 fecal samples and measured fecal testosterone metabolite levels in 19 adult male white-handed gibbons (Hylobates lar) from 13 groups living in the Khao Yai National Park, Thailand, to examine the extent to which androgen output is related to sociodemographic variables (social organization, social status, presence of infants, age) in a socially flexible species, i.e., pair-living/multimale groups. We predicted that androgen levels would be higher in males 1) that live in potentially more unstable single-male/single-female units; 2) that are primary (dominant) vs. secondary; 3) that live in groups with dependent infants; and 4) that are of prime vs. senior age. We found marked differences in androgen levels among males and a significant effect of time of the year. Males living in pairs exhibited significantly higher androgen concentrations vs. males living in multimale groups, and males residing in groups with infants showed a significant increase in androgen levels throughout the sampling year. However, we found no relationship with male age or social status. The increased androgen output found in both pair-living males and those residing with infants might be a physiological mechanism that facilitates male aggression to cope with potential threats posed by social challenges and the demand for infant/group defense, respectively. More generally, our data indicate that in socially flexible species male androgen output is less strongly linked to key life-history variables than in species that live permanently in multimale–multifemale groups.

The Participation Of Community And Stakeholders In Environmental Issue Management For Green Tourism In Thailand

The objective of this research is to study the environmental issues for green tourism development of Khao Yai Forest Complex by analyzing opportunities, threats, strengths, and weaknesses from the stakeholders perspectives. According to weighted average score of strengths, weaknesses, opportunities, and threats, Khao Yai National Park is in the quadrant of SO (strengths and opportunities), indicating that they have strengths and opportunities and should therefore use aggressive strategy. Thap Lan National Park is in the quadrant of ST (strengths and threats), indicating that they have strengths and threats and should therefore use competitive strategy. In contrast, Pang Sida National Park, Ta Phraya National Park, and Dongyai Wildlife Sanctuary are in the quadrant of WT (weaknesses and threats), indicating that they have weaknesses and threats and should therefore use defensive strategy.

Do Ranger Stations Deter Poaching Activity in National Parks in Thailand?

AbstractAs protected areas become more accessible via transportation networks, fragmentation, and encroachment from the borders, carnivores in these areas frequently decline. To counter these pressures, patrolling and active wildlife enforcement are widely accepted as fundamental conservation strategies. Using the case example of Khao Yai National Park (KYNP) and data from a camera trap survey, we modeled and evaluated the effectiveness of ranger stations in reducing human access and illegal activities, and in increasing prey and predator presence. This type of data and analysis is needed to monitor and evaluate enforcement effectiveness and develop adaptive management strategies. At KYNP, we used camera‐trapping data as a proxy to evaluate whether or not a positive impact of ranger stations on wildlife distribution could outweigh edge effects from human disturbance. We assessed factors affecting the distribution of poachers and wildlife using Maxent. Our analysis was based on 217 camera trap locations (6260 trap nights) and suggests that ungulates and poachers persist nearby ranger stations. Rangers should increase patrolling efforts of border areas; however, increasing wildlife patrolling in inaccessible areas with mobile range units may be more effective than establishing more ranger stations along park boundaries.

Molecular phylogenies reveal host‐specific divergence of Ophiocordyceps unilateralis sensu lato following its host ants

Ophiocordyceps unilateralis (Hypocreales, Ascomycetes) is an entomopathogenic fungus specific to formicine ants (Formicinae, Hymenoptera). Previous works have shown that the carpenter ant Camponotus leonardi acts as the principal host with occasional infections of ants from the genus Polyrhachis (sister genus of Camponotus). Observations were made on the permanent plots of Mo Singto, Khao Yai National Park of Thailand according to which O. unilateralis was found to occur predominantly on three host species: C. leonardi, C. saundersi and P. furcata. Molecular phylogenies of the elongation factor 1-α and β-Tubulin genes indicate a separation of O. unilateralis samples into three clades, reflecting specificity to each of the three different ant species. Samples collected from P. furcata and from C. leonardi were found to form sister groups with samples from C. saundersi forming an outgroup to the latter. Additional samples collected from unidentified ant species of Camponotus and Polyrhachis were positioned as outgroups to those samples on identified species. These results demonstrate that O. unilateralis is clearly not a single phylogenetic species and comprises at least three species that are specific to different host ant species. These cryptic species may arise through recent events of speciation driven by their specificity to host ant species.

Thismia filiformis, a new species of Thismiaceae (formerly Burmanniaceae) from Thailand

Thismia filiformis is described and illustrated as a new species from Khao Yai National Park, Thailand. The conservation status and affinities of the new species are discussed.

Interspecific territoriality in gibbons (Hylobates lar and H. pileatus) and its effects on the dynamics of interspecies contact zones

We investigated the ecology and interspecific interactions of the two gibbon species (Hylobates lar and H. pileatus) that overlap in distribution within a narrow zone of contact in the headwaters of the Takhong River at Khao Yai National Park in central Thailand. The zone is about 10-km wide, with phenotypic hybrids comprising 6.5% of the adult population. We compared species with respect to diet, territory size, intra- and interspecific group encounters, and territory quality. The two gibbon species exploited the same types of resources within their territories despite variation in the relative abundance of food-plant species between territories. The gibbons were interspecifically territorial, and males of both species displayed aggressive behaviors at both intraspecific and interspecific territorial boundaries. There was no marked difference in the amount of overlap between territories of conspecific and heterospecific pairs of groups. Although the habitat was not homogeneous, territory quality did not vary significantly between species. The species have not diverged in habitat preference or in diet. Neither species dominated in interspecific encounters, and both were reproducing well in the contact zone. We analyzed the potential consequences of several types of interspecific interactions on individual dispersal options and on the structure of the contact zone. Interference competition through interspecific territoriality affects the dispersal of individuals into the range of the other species. In general, territorial competition coupled with limited hybridization leads to predictions of a narrow contact zone or parapatry between species; thus, behavioral and ecological interactions between species need to be considered as potential factors in explaining range borders of primate species.

The anti-predator behaviour of wild white-handed gibbons (Hylobates lar)

Predation on gibbons is rarely observed in the wild. However, the gibbons' moderate body size and relatively small social groups suggest high vulnerability to predation. To assess the role of predation and to study their anti-predator behaviour, we presented visual predator models to nine groups of wild white-handed gibbons at Khao Yai National Park, Thailand. We measured subjects' immediate and delayed responses to four potential predators: tiger, clouded leopard, crested serpent eagle and reticulated python. Subjects reliably approached all four predators. In response to tigers and leopards, they additionally produced predator-specific songs and defecated copiously. In terms of delayed responses, distance between mated adults decreased, but only after exposure to the tiger model. In response to eagles and pythons, gibbons consistently vocalised, but this did not always include predator singing, and we found no long-term effects in overall activity or strata use. However, during 6 of 26 predator encounters, the gibbons produced songs with a structure that was intermediate between a duet song and a predator song more than 20 min after the predator encounter, indicating a long-term effect on their vocal behaviour. This study demonstrates that gibbons discriminate between different potential predators and respond to them with adaptive anti-predator behaviour, which include predator-specific vocal responses. We conclude that gibbons are not immune to predation and that terrestrial predators elicit consistent immediate and delayed anti-predation responses.

Sleeping site selection and presleep behavior in wild pigtailed macaques

Several factors are likely to control sleeping site selection and presleep behavior in nonhuman primates, including predation risk and location of food resources. We examined the effects of these factors on the sleeping behavior of northern pigtailed macaques (Macaca leonina). While following a troop living in the surroundings of the Visitor Center of Khao Yai National Park (Thailand), we recorded the physical characteristics and location of each sleeping site, tree, the individuals' place in the tree, posture, and behavior. We collected data for 154 nights between April 2009 and November 2010. The monkeys preferred tall sleeping trees (20.9 ± SD 4.9 m) and high sleeping places (15.8 ± SD 4.3 m), which may be an antipredator strategy. The choice of sleeping trees close to the last (146.7 ± SD 167.9 m) or to the first (150.4 ± SD 113.0 m) feeding tree of the day may save energy and decrease predation risk when monkeys are searching for food. Similarly, the choice of sleeping sites close to human settlements eases the access to human food during periods of fruit scarcity. Finally, the temporal pattern of use of sleeping sites, with a preference for four of the sleeping sites but few reuses during consecutive nights, may be a trade-off between the need to have several sleeping sites (decreasing detection by predators and travel costs to feeding sites), and the need to sleep in well-known sites (guaranteeing a faster escape in case of predator attack).

Tourists Expectation And Perception Towards Environmental Issue Management For Green Tourism Of Khao Yai National Park

This paper presents the results of a study conducted to evaluate tourists perceptions of environmental issue management in Khao Yai National Park, where has been inscribed as a natural UNESCO World Heritage Site under the name Dong Phaya YenKhaoYai Forest Complex since 2005. The information could assist in addressing tourists perception in order to improve the management of the site for sustainable green tourism. The current study was carried out in 4 sites located in the complex. The sample size for this research is 654 tourists. The study analyzes six issues of environmental issue management, which are pollution, facilities, safety, regulation enforcement, eco-tourism activities, and stakeholder collaboration. Each dimension was rated both in term of expectation and perception. Positive gaps are found between the scores of perception and expectation of environmental issue management, implying that environmental issue management in the complex is more effective than tourists expect it to be.

Is grooming used as a commodity in wild white-handed gibbons, Hylobates lar?

Biological market theory is an extension of the idea of reciprocal altruism, as a mechanism to explain altruistic acts between unrelated individuals in a more flexible system of exchanging commodities. In nonhuman primates, social grooming has been used to test predictions in both contexts: reciprocal altruism or biological markets. Specifically, in species in which males cannot coerce females to mate, males may attempt to interchange grooming for mating, particularly when females are fertile and mating opportunities are more likely to arise. We tested whether wild white-handed gibbon males from Khao Yai National Park, Thailand, increased their grooming activity when the female partner was fertile. Adult females and males of our study population are codominant (in terms of aggression), they live in pairs or small multimale groups and mate promiscuously. We analysed grooming episodes during 2760 observation-hours in 12 groups separately for females’ reproductive condition (cycling/pregnant/ lactating) based on noninvasive measures of ovarian hormone activity. We found that males groomed females more than vice versa and more grooming was exchanged when females were cycling than during pregnancy or lactation. The number of copulations/day was elevated when females were cycling, and females copulated more frequently with males on days when they received more grooming. When males increased their grooming efforts, females also increased their grooming of males, perhaps to equalize give and take. Although grooming might be reciprocated because of intrinsic benefits of receiving grooming, we conclude that males also interchange grooming as a commodity for sexual opportunities during a female’s fertile period.

Nonredundancy in the dispersal network of a generalist tropical forest tree

Plant species with generalized dispersal mutualisms are considered to be robust to local frugivore extinctions because of redundancy between dispersal agents. However, real redundancy can only occur if frugivores have similar foraging and ranging patterns and if fruit is a limiting resource. We evaluated the quantitative and qualitative contributions of seed dispersers for an endochorus mast-fruiting species, Prunus javanica (Rosaceae) in Khao Yai National Park, Thailand, to evaluate the potential redundancy of dispersers. Data were collected from tree watches, seed/fruit traps, and seed transects under and away from fruiting trees, feeding and seed deposition by gibbons (Hylobates lar), and evaluations of seed and first-year seedling survival. We identified three clusters of dispersers within the network. Most (>80%) frugivore species observed were small birds and squirrels that were not functional dispersers, dropping most seeds under or very near the tree crown, where seedling survival was ultimately nil. Monkeys (Macaca leonina) were low-quality, short-range dispersers, but they dispersed large numbers of seeds and were responsible for 67% of surviving first-year seedlings. Gibbons and Oriental Pied Hornbills (Anthracoceros albirostris) handled few fruits, but they provided the highest quality service by carrying most seeds away from the canopy to medium and long distances, respectively. Although there was overlap in the deposition patterns of the functional dispersers, they displayed complementary, rather than redundant, roles in seed dispersal. Satiation of all functional dispersers further limited their capacity to "replace" one another. Redundancy must be evaluated at the community level because each type of disperser may shift to different species in the non-masting years of P. javanica. Our results underscore the need for research on broader spatial and temporal scales, which combines studies of dispersal and plant recruitment, to better understand mechanisms that maintain network stability.

Using Relative Abundance Indices from Camera-Trapping to Test Wildlife Conservation Hypotheses – An Example from Khao Yai National Park, Thailand

Khao Yai National Park (KYNP) is well known for its biodiversity and has the potential to serve as a regional model for wildlife conservation. From October 2003 through October 2007, the managers of KYNP conducted a Carnivore Conservation Project to develop and implement long-term monitoring of their large mammal populations. We present these data as an example to demonstrate the usefulness of long-term camera-trapping despite data that cannot be fitted to mark/recapture or occupancy statistical frameworks. Overall, a relatively high number of camera trap photographs was obtained for viverrids (four species; 44 photos) and ursids (two species; 39 photos). However, a relatively low number (range, one to eight) of camera trap photographs was obtained for each of the four felid species and two canid species detected by cameras. Of a total survey effort of 6,260 trap nights, no tigers ( Panthera tigris) were detected by camera traps, suggestive of at best a small, non-viable tiger population. Compared to previous camera-trapping efforts at KYNP, we expanded intensive sampling beyond the core area to include all zones and edges of the park. We found significantly lower relative abundance indices (RAIs) for certain mammal species, and collectively for all mammals compared to data obtained in 1999–2000 from 34 similar survey locations, suggesting population declines linked to increased human activity. Information from long-term camera-trapping can provide critical information on the occurrence of elusive species, hotspots, the role of invasive or domestic species, and an indication of the effectiveness of patrolling and other management and conservation interventions.

Influence of fruit on habitat selection of Asian bears in a tropical forest

AbstractWild bear populations in Southeast Asia are threatened with extinction, but the ecology and distribution of the 2 species occurring in the region's protected areas is poorly known, so there is little scientific basis underlying conservation strategies. We used bear signs, primarily claw marks on climbed trees, to study habitat selection and distribution of Asiatic black bear (Ursus thibetanus) and sun bear (Helarctos malayanus) across Khao Yai National Park, Thailand from March to December 2008. We found black bear claw marks in 24 of 30 random sample blocks (80%), indicating that this species was widely distributed across Khao Yai. Sun bear signs were much scarcer: their claw marks occurred in 11 blocks (37%); data were too sparse for sun bear so we limited our focus to Asiatic black bear. Using logistic regression, we found that fruit abundance best explained variation in presence of black bear, whereas human disturbance, distance to park edge, elevation, and ground cover had little influence. Fruits appear to be a key resource for Asiatic black bears, and factors affecting fruit abundance or shifts in seasonality (e.g., climate change) will impact bear populations. Knowledge of this relationship will allow managers to be more proactive in managing bears. We recommend using sign surveys for monitoring changes in black bear occupancy as they are inexpensive, efficient, and can be conducted by trained park rangers. © 2011 The Wildlife Society.