| home-range characteristics and the influence of seasonality on female reproduction in white-handed gibbons (hylobates lar) at khao yai national park, thailand. | a three-year (2001-2003) study was carried out on the home range characteristics of seven wild white-handed gibbon (hylobates lar) groups focusing on the spatio-temporal distribution of food resources at khao yai national park in northeastern thailand. these results were combined with 23 years (1980-2003) of reproductive performance data on seven females from the same focal groups. reproductive performance was equal among females with regard to birth, weaning and maturation ratios, and independe ... | 2008 | 17960726 |
| species specificities among primates probed with commercially available fluorescence-based multiplex pcr typing kits. | to assess species specificities among primates of signals from short tandem repeat (str) loci included in two commercially available kits, mainly the ampflstr identifiler kit and additionally the geneprint powerplex 16 system, we analyzed 69 dna samples from 22 nonhuman primate species representing apes, old world monkeys (owms), new world monkeys (nwms), and prosimians. each prosimian species and the nwm cotton-top tamarin apparently lacked all str loci probed. only one peak, the amelogenin-x p ... | 2015 | 25899252 |
| three-dimensional analysis of nonhuman primate trabecular architecture using micro-computed tomography. | until recently, detailed analyses of the architecture of nonhuman primate cancellous bone have not been possible due to a combination of methodological constraints, including poor resolution imaging or destructive protocols. the development of micro-computed tomography (microct) and morphometric methods associated with this imaging modality offers anthropologists a new means to study the comparative architecture of cancellous bone. specifically, microct will allow anthropologists to investigate ... | 2001 | 11471131 |
| 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-livi ... | 2013 | 23440877 |
| phylogenetic relationships and divergence dates of the whole mitochondrial genome sequences among three gibbon genera. | phylogenetic relationships of gibbons (4 genera, 12 species) deduced from short/partial mitochondrial dna sequences were with low resolution and inconsistent. their divergence over the short period of time may require longer sequences for the higher resolution. to solve the problems, we newly sequenced the whole mitochondrial genome of hylobates agilis, hylobates pileatus, nomascus sp. and symphalangus syndactylus. a highly resolved phylogenetic tree was obtained for the mitochondrial genome in ... | 2010 | 20138221 |
| cues to androgens and quality in male gibbon songs. | animal vocal signals may provide information about senders and mediate important social interactions like sexual competition, territory maintenance and mate selection. hence, it is important to understand whether vocal signals provide accurate information about animal attributes or status. gibbons are non-human primates that produce loud, distinctive and melodious vocalizations resembling more those of birds than of other non-human primates. wild gibbons are characterized by flexibility in socia ... | 2013 | 24367551 |
| tracking the complex flow of chromosome rearrangements from the hominoidea ancestor to extant hylobates and nomascus gibbons by high-resolution synteny mapping. | in this study we characterized the extension, reciprocal arrangement, and orientation of syntenic chromosomal segments in the lar gibbon (hylobates lar, hla) by hybridization of a panel of approximately 1000 human bac clones. each lar gibbon rearrangement was defined by a splitting bac clone or by two overlapping clones flanking the breakpoint. a reconstruction of the synteny arrangement of the last common ancestor of all living lesser apes was made by combining these data with previous results ... | 2008 | 18552313 |
| analysis of the genetic relationships among thai gibbon species using aflp markers. | cytogenetic studies of three gibbon species using conventional banding patterns were investigated showing an identical number of 44 diploid chromosomes. they are assumed to have common evolutionary relationships. for in depth study, molecular markers were assessed using the amplified fragment length polymorphism (aflp) method. with seven successful primer combinations, a total of 1669 scorable bands were generated. the resulting bands were used for dendrogram construction. from the dendrogram, t ... | 2007 | 19069957 |
| sterile pyuria in a population of wild white-handed gibbons (hylobates lar). | urinalysis is an emerging method for monitoring the health and energy balance of wild primates. here, we report the first urinalysis of wild gibbons. we used multi-reagent test strips to monitor the health status of 52 individual white-handed gibbons (hylobates lar) inhabiting khao yai national park, thailand. most urinary reference values were within normal ranges; however, regardless of age- and sex-class or monthly fruit productivity, we found unexpectedly high rates of urinary leukocytes (50 ... | 2009 | 19514046 |
| visual preference in a human-reared agile gibbon (hylobates agilis). | visual preference was evaluated in a male agile gibbon. the subject was raised by humans immediately after birth, but lived with his biological family from one year of age. visual preference was assessed using a free-choice task in which five or six photographs of different primate species, including humans, were presented on a touch-sensitive screen. the subject touched one of them. food rewards were delivered irrespective of the subject's responses. we prepared two types of stimulus sets. with ... | 2010 | 19882208 |
| frequent gene conversion events between the x and y homologous chromosomal regions in primates. | mammalian sex-chromosomes originated from a pair of autosomes. a step-wise cessation of recombination is necessary for the proper maintenance of sex-determination and, consequently, generates a four strata structure on the x chromosome. each stratum shows a specific per-site nucleotide sequence difference (p-distance) between the x and y chromosomes, depending on the time of recombination arrest. stratum 4 covers the distal half of the human x chromosome short arm and the p-distance of the strat ... | 2010 | 20650009 |
| first isolation of the anamorph of kazachstania heterogenica from a fatal infection in a primate host. | we describe the isolation of the anamorph of the ascomycetous yeast kazachstania heterogenica from a fatal infection in a 2 year, 9-month-old female white-handed gibbon (hylobates lar). the yeast was observed in histological sections (lung and intestine) and co-isolated with the bacterium escherichia coli from different internal organs. this is the first report of the recovery of this yeast from a fatal infection in a primate host. | 2011 | 21539504 |
| 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 potenti ... | 2011 | 21870623 |
| structural and mechanical indicators of limb specialization in primates. | the structural mechanics of femora and humeri from primates representing a wide spectrum of habitual locomotor activities were examined to determine how cross-sectional properties vary with functional specializations of the extremities. average bending rigidities of the midshaft of humerus and femur were measured in 60 individuals of four nonhuman primate species (macaca nemestrina, macaca fascicularis, presbytis cristata, hylobates lar) using single-beam photon absorptiometry. linear regression ... | 2013 | 4093079 |
| mitochondrial evidence for multiple radiations in the evolutionary history of small apes. | gibbons or small apes inhabit tropical and subtropical rain forests in southeast asia and adjacent regions, and are, next to great apes, our closest living relatives. with up to 16 species, gibbons form the most diverse group of living hominoids, but the number of taxa, their phylogenetic relationships and their phylogeography is controversial. to further the discussion of these issues we analyzed the complete mitochondrial cytochrome b gene from 85 individuals representing all gibbon species, i ... | 2010 | 20226039 |
| age related decline in female lar gibbon great call performance suggests that call features correlate with physical condition. | white-handed gibbons (hylobates lar) are small asian apes known for living in stable territories and producing loud, elaborate vocalizations (songs), often in well-coordinated male/female duets. the female great call, the most conspicuous phrase of the repertoire, has been hypothesized to function in intra-sexual territorial defense. we therefore predicted that characteristics of the great call would correlate with a caller's physical condition, and thus might honestly reflect resource holding p ... | 2016 | 26728088 |
| long-term home range use in white-handed gibbons (hylobates lar) in khao yai national park, thailand. | ranging behavior is an important element of how nonhuman primates obtain sufficient resources to ensure biological maintenance and reproductive success. as most primates live in permanent social groups, group members must balance the benefits of group living with the costs of intragroup competition for resources. one way to mitigate the cost of intragroup feeding competition is to increase foraging-related travel, thereby increasing the number of patches visited. as a result we might expect home ... | 2016 | 26456317 |
| comprehensive analyses of white-handed gibbon chromosomes enables access to 92 evolutionary conserved breakpoints compared to the human genome. | gibbon species (hylobatidae) impress with an unusually high number of numerical and structural chromosomal changes within the family itself as well as compared to other hominoidea including humans. in former studies applying molecular cytogenetic methods, 86 evolutionary conserved breakpoints (ecbs) were reported in the white-handed gibbon (hylobates lar, hla) with respect to the human genome. to analyze those ecbs in more detail and also to achieve a better understanding of the fast karyotype e ... | 2015 | 25926034 |
| context-specific close-range "hoo" calls in wild gibbons (hylobates lar). | close range calls are produced by many animals during intra-specific interactions, such as during home range defence, playing, begging for food, and directing others. in this study, we investigated the most common close range vocalisation of lar gibbons (hylobates lar), the 'hoo' call. gibbons and siamangs (family hylobatidae) are known for their conspicuous and elaborate songs, while quieter, close range vocalisations have received almost no empirical attention, perhaps due to the difficult obs ... | 2015 | 25888361 |
| lar gibbon (hylobates lar) great call reveals individual caller identity. | gibbons (family hylobatidae) produce loud, elaborate vocalizations (songs), often in well-coordinated male/female duets. the female's great call, the most conspicuous phrase of the gibbon vocal repertoire, functions primarily to mediate territorial defense. despite the fact that lar gibbons (hylobates lar) are the most widely distributed and well researched hylobatid species and produce a rich vocal repertoire, the individual-specificity of their great calls has not previously been quantified. i ... | 2015 | 25800578 |
| gibbon (hylobates lar) reintroduction success in phuket, thailand, and its conservation benefits. | we summarize the results from a long-term gibbon reintroduction project in phuket, thailand, and evaluate its benefits to conservation. between october 2002 and november 2012, eight breeding families of white-handed gibbons (hylobates lar) were returned to the wild in khao phra thaew non-hunting area (kpt). wild gibbons were extirpated from phuket island by the early 1980s, but the illegal wildlife trade has continued to bring young gibbons from elsewhere to the island's popular tourist areas as ... | 2015 | 25597291 |
| primary bone microanatomy records developmental aspects of life history in catarrhine primates. | a central challenge in human origins research is to understand how evolution has shaped modern human life history. as fossilized remains of our ancestors provide the only direct evidence for life history evolution, efforts to reconstruct life history in paleontological contexts have focused on hard tissues, particularly on dental development. however, among investigators of other vertebrate groups, there is a long tradition of examining primary bone microstructure to decipher growth rates and ma ... | 2016 | 26989017 |
| sexual swellings in wild white-handed gibbon females (hylobates lar) indicate the probability of ovulation. | conspicuous sexual swellings in the females of some primate species have been a focus of scientific interest since darwin first wrote about them in 1871. to understand these visual signals, research focused on exaggerated sexual swellings of old world primates. however, some primate species develop much smaller sexual swellings and it is as yet unclear if these smaller swellings can serve similar functions as those proposed for exaggerated swellings, i.e. advertising fertility to attract mates. ... | 2007 | 17137580 |
| regional variability in secondary remodeling within long bone cortices of catarrhine primates: the influence of bone growth history. | secondary intracortical remodeling of bone varies considerably among and within vertebrate skeletons. although prior research has shed important light on its biomechanical significance, factors accounting for this variability remain poorly understood. we examined regional patterning of secondary osteonal bone in an ontogenetic series of wild-collected primates, at the midshaft femur and humerus of chlorocebus (cercopithecus) aethiops (n = 32) and hylobates lar (n = 28), and the midshaft femur of ... | 2008 | 18691379 |
| locational diversity of alpha satellite dna and intergeneric hybridization aspects in the nomascus and hylobates genera of small apes. | recently, we discovered that alpha satellite dna has unique and genus-specific localizations on the chromosomes of small apes. this study describes the details of alpha satellite localization in the genera nomascus and hylobates and explores their usefulness in distinguishing parental genome sets in hybrids between these genera. fluorescence in situ hybridization was used to establish diagnostic criteria of alpha satellite dna markers in discriminating small ape genomes. in particular we establi ... | 2014 | 25290445 |
| extra-pair paternity confirmed in wild white-handed gibbons. | knowledge of the genetic mating system of animal species is essential for our understanding of the evolution of social systems and individual reproductive strategies. in recent years, genetic methods have uncovered an unexpected diversity of paternal genetic contributions across diverse animal social mating systems, but particularly in pair-living species. in most pair-living birds, for example, genetic and behavioral observations have confirmed a previously unknown significance of extra-pair co ... | 2013 | 23877831 |
| fibre type composition in the lumbar perivertebral muscles of primates: implications for the evolution of orthogrady in hominoids. | the axial musculoskeletal system is important for the static and dynamic control of the body during both locomotor and non-locomotor behaviour. as a consequence, major evolutionary changes in the positional habits of a species are reflected by morpho-functional adaptations of the axial system. because of the remarkable phenotypic plasticity of muscle tissue, a close relationship exists between muscle morphology and function. one way to explore major evolutionary transitions in muscle function is ... | 2014 | 24433382 |
| locomotion behavior of cao vit gibbon (nomascus nasutus) living in karst forest in bangliang nature reserve, guangxi, china. | the cao vit gibbon is a critically endangered species. only approximately 110 individuals remain in degraded karst forest along the china-vietnam border. karst forest is unusual gibbon habitat. currently, the canopy height of cao vit gibbon habitat is approximately 10 m. research on the locomotor behavior of gibbons living in this particular forest type might provide important insight into locomotor stability and variability of gibbons. we used 5 min scan samples to record the locomotion mode, s ... | 2013 | 24344959 |
| novel variable number of tandem repeats of gibbon maoa gene and its evolutionary significance. | variable number of tandem repeats (vntrs) are scattered throughout the primate genome, and genetic variation of these vntrs have been accumulated during primate radiation. here, we analyzed vntrs upstream of the monoamine oxidase a (maoa) gene in 11 different gibbon species. an abundance of truncated vntr sequences and copy number differences were observed compared to those of human vntr sequences. to better understand the biological role of these vntrs, a luciferase activity assay was conducted ... | 2014 | 25360715 |
| the ecology of white-handed and pileated gibbons in a zone of overlap and hybridization in thailand. | the study of related species in contact zones can elucidate what factors mediate species coexistence and geographical distributions. we investigated niche overlap and group interactions of two gibbon species and their hybrids co-occurring in a zone of overlap and hybridization. | 2017 | 28726303 |
| development of pelvic sexual dimorphism in hylobatids: testing the obstetric constraints hypothesis. | pelvic sexual dimorphism in primates is typically seen as the result of female-specific adaptations to obstetric constraints, which arise from the tight fit between the neonate head and the maternal pelvis. however, it remains debated to which extent pelvic dimorphism is a correlate of obstetric constraints, of body size dimorphism, and/or of other factors. also, little is known on how pelvic dimorphism develops. here we use methods of biomedical imaging and geometric morphometrics to address th ... | 2017 | 28406562 |
| application of multicolor banding combined with heterochromatic and locus-specific probes identify evolutionary conserved breakpoints in hylobates pileatus. | the question what makes homo sapiens sapiens (hsa) special among other species is one of the basic questions of mankind. a small contribution to answer this question is to study the chromosomal constitution of hsa compared to other, closely related species. in order to check the types and extent of evolutionary conserved breakpoints we studied here for the first time the chromosomes of hylobates pileatus (hpi) compared to hsa and hylobates lar (hla) by means of molecular cytogenetics. | 2016 | 26893612 |
| effectiveness of primate seed dispersers for an "oversized" fruit, garcinia benthamii. | the largest fruits found in tropical forests may depend on complementary seed dispersal strategies. these fruits are dispersed most effectively by megafauna, but populations can persist where megafauna are absent or erratic visitors. smaller animals often consume these large fruits, but their capacity to disperse these seeds effectively has rarely been assessed. we evaluated the contributions of gibbons (hylobates lar) and other frugivores in the seed dispersal of the megafaunal fruit garcinia b ... | 2015 | 26649394 |
| soprano singing in gibbons. | diversifications in primate vocalization, including human speech, are believed to reflect evolutionary modifications in vocal anatomy and physiology. gibbon song is acoustically unique, comprising loud, melodious, penetrating pure tone-like calls. in a white-handed gibbon, hylobates lar, the fundamental frequency (f(0) ) of song sounds is amplified distinctively from the higher harmonics in normal air. in a helium-enriched atmosphere, f(0) does not shift, but it is significantly suppressed and 2 ... | 2012 | 22926979 |
| 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 ... | 2013 | 22892937 |
| patterns of ingestive behavior and anterior tooth use differences in sympatric anthropoid primates. | little research has been directed towards the examination of ingestive behaviors in wild primates. this paper describes a naturalistic study of anterior tooth use in four sympatric anthropoid species: hylobates lar, macaca fascicularis, pongo pygmaeus, and presbytis thomasi. instantaneous group scan data were collected during nearly 1,800 hours of observation between august 1990 and july 1991 at the ketambe research station in the gunung leuser national park, sumatra, indonesia. ingestive behavi ... | 1994 | 7802096 |
| sex ratio bias in managed populations of hylobatids. | a number of explanations have been proposed for the occurrence of sex ratio bias in primates, including the trivers-willard hypothesis on differential investment, local resource competition or enhancement as a result of sex-biased dispersal, dominance-related advantages conferred on one sex but not the other, and the fragile male hypothesis. however, none of these theories was thought to be applicable to monogamous primate species. here, we examine data on zoo-housed populations of three hylobat ... | 2011 | 22248927 |
| 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 sp ... | 2012 | 22127502 |
| [comparative karyotyping of our gibbon species or subspecies (author's transl)]. | the karyotypes of several hylobatidae hylobates (hylobates) lar pileatus, h. (nomascus) concolor leucogenys, h. (n.) concolor ssp, hybrid h. (n.) concolor leucogenys x h. (n.) concolor gabriellae, h (symphalangus) syndactylus are compared both each others and also to those of other primates. many rearrangements of their chromosomes have occurred during their evolution, and some polymorphism still exists in the living species. this high rate of chromosome rearrangements is in contrast with their ... | 1982 | 6979300 |
| unilateral hypoplasia of the palate and associated structures in a white-handed gibbon (hylobates lar). | a hole in the palate was detected in a ten-day-old white-handed gibbon (hylobates lar). the clinical observations demonstrated a unilateral hypoplasia of the palate, of the maxilla, of a tooth, and of the adjacent facial musculature and skin. | 1981 | 7343673 |
| telemetered electromyography of forelimb muscle chains in gibbons (hylobates lar). | electromyographic studies of brachiation in the gibbon controvert deductions, based on dissection, about the purported functions of muscle chains in the hylobatid forelimb. neither force conduction distally along the components of the chains nor simultaneity of muscular contraction occurs in brachiation. rather, the unique structure of the forelimb is probably the result of evolved changes in the short head of biceps brachii to enhance its role as a forearm flexor. | 1980 | 7367886 |
| habitat quality and populations of two sympatric gibbons (hylobatidae) on a mountain in malaya. | sympatric gibbon species hylobates lar and h. syndactylus were censused on a mountain in malaya (west malaysia). habitat quality was assessed between 380- and 1,525-m altitudes. h. syndactylus was found to occur up to altitudes higher than does h. lar, and this is discussed with reference to the two species' divergent foraging strategies indicated by previous research. it is suggested that gibbons are restricted in their altitudinal range by an increasingly unfavourable ratio of food consumed to ... | 1980 | 7419138 |
| isolation and tissue distribution of type-c virus and viral components from a gibbon ape (hylobates lar) with lymphocytic leukemia. | | 1978 | 74897 |
| gibbon travel paths are goal oriented. | remembering locations of food resources is critical for animal survival. gibbons are territorial primates which regularly travel through small and stable home ranges in search of preferred, limited and patchily distributed resources (primarily ripe fruit). they are predicted to profit from an ability to memorize the spatial characteristics of their home range and may increase their foraging efficiency by using a 'cognitive map' either with euclidean or with topological properties. we collected r ... | 2011 | 21221693 |
| brief communication: three-dimensional motion analysis of hindlimb during brachiation in a white-handed gibbon (hylobates lar). | in brachiating gibbons, it is thought that there is little movement in the hindlimb joints and that lateral body movement is quite limited. these hypotheses are based on naked-eye observations, and no quantitative motion analyses of the hindlimbs have been reported. this study quantitatively describes the three-dimensional movements of the lower trunk and distal thigh during continuous-contact brachiation in a white-handed gibbon (hylobates lar) to evaluate the roles of the trunk and hindlimb. t ... | 2010 | 20607695 |
| muscle moment arms of the gibbon hind limb: implications for hylobatid locomotion. | muscles facilitate skeletal movement via the production of a torque or moment about a joint. the magnitude of the moment produced depends on both the force of muscular contraction and the size of the moment arm used to rotate the joint. hence, larger muscle moment arms generate larger joint torques and forces at the point of application. the moment arms of a number of gibbon hind limb muscles were measured on four cadaveric specimens (one hylobates lar, one h. moloch and two h. syndactylus). the ... | 2010 | 20447251 |
| anatrichosoma infection in two white-handed gibbons. | multiple nodular lesions of the nematode anatrichosoma were observed on the ears, lips, nares, and eyelids of 2 adult gibbons (hylobates lar). the lesions were 4 to 7 mm in diameter, gray to pink, and firm on palpation. microscopically, the nodules consisted of thickened epidermis having intraepidermal cysts containing the nematode and eggs. live female nematodes were recovered from fresh biopsy specimens. because male specimens were not obtained, the species could not be identified. | 1975 | 1176358 |
| long-term observations of siamang behaviour. | long-term observations are presented on the behaviour of the siamang ape, symphalangus syndactylus, in the lowland forest of central malaya. the data were collected during two dry and three fruiting seasons between 1969 and 1973 inclusive on two groups with adjacent ranges; comparisons are made within and between sample periods, and between groups. the influence of weather on daily activities is considered. food intake is analysed in terms of number of food trees, number of visits to these trees ... | 1975 | 1140747 |
| mechanical constraints on the functional morphology of the gibbon hind limb. | gibbons utilize a number of locomotor modes in the wild, including bipedalism, leaping and, most of all, brachiation. each locomotor mode puts specific constraints on the morphology of the animal; in some cases these may be complementary, whereas in others they may conflict. despite several studies of the locomotor biomechanics of gibbons, very little is known about the musculoskeletal architecture of the limbs. in this study, we present quantitative anatomical data of the hind limb for four spe ... | 2009 | 19627388 |
| functional differences within a guild of tropical mammalian frugivores. | many plants interact with groups of mutualist pollinators and seed dispersers. a key issue for both basic ecology and conservation is whether the different species within these guilds of mutualist animals are functionally equivalent. comparing the relative effects of sympatric mutualists is important for understanding the evolution of multispecies mutualisms and for predicting mutualism stability in the face of anthropogenic change. however, empirical comparisons of the population-level impacts ... | 2009 | 19341139 |
| lymphosarcomas in two gibbons (hylobates lar) with associated c-type virus. | | 1973 | 4352755 |
| hypertrophic osteoarthropathy in a gibbon (hylobates lar). | | 1972 | 4648354 |
| lymphoblastic lymphosarcoma in two white-handed gibbons, hylobates lar. | | 1972 | 4627751 |
| electrically elicited vocalizations in the gibbon hylobates lar (hylobatidae), and their behavioral significance. | | 1972 | 5048149 |
| electrically elicited vocalizations in the gibbon, hylobates lar (hylobatidae). | | 1972 | 4559354 |
| breeding gibbons (hylobates lar entelloides) in the laboratory. | | 1969 | 4244897 |
| comparative studies on the pathology and host physiology of malarias. 3. plasma free fatty acids in normal and malarious gibbons (hylobates lar). | | 1967 | 5634128 |
| burkitt's lymphoma in a white-handed gibbon (hylobates lar). | | 1967 | 6067459 |
| [birth and early development of 2 gibbons (hylobates lar l.)]. | | 1967 | 6030827 |
| detection of hev-specific antibodies in four non-human primate species, including great apes, from different zoos in germany. | the hepatitis e virus (hev) has been described in humans and various animal species in different regions of the world. however, the knowledge on natural hev infection in non-human primates and the corresponding risk of zoonotic transmission is scarce. to determine whether primates in captivity are affected by hev infection, we investigated 259 individual sera of clinically healthy non-human primates of 14 species from nine german zoos. using a commercial double-antigen-sandwich elisa and a comme ... | 2018 | 29168441 |
| object permanence tests on gibbons (hylobatidae). | ten gibbons of various species (symphalangus syndactylus, hylobates lar, nomascus gabriellae, and nomascus leucogenys) were tested on object permanence tasks. three identical wooden boxes, presented in a linear line, were used to hide pieces of food. the authors conducted single visible, single invisible, double invisible, and control displacements, in both random and nonrandom order. during invisible displacements, the experimenter hid the object in her hand before putting it into a box. the pe ... | 2008 | 19014264 |
| the body center of mass in primates: is it more caudal than in other quadrupedal mammals? | whole body center of mass (bcom) position values are lacking for a comparative sample of primates. therefore, it still remains unknown whether the bcom in primates is more posteriorly located than in other mammals. the aim of the present report is to provide data for a large sample of primate species and to compare the position of the bcom in primates to non-primate mammals. | 2019 | 30839107 |
| a most distant intergeneric hybrid offspring (larcon) of lesser apes, nomascus leucogenys and hylobates lar. | unlike humans, which are the sole remaining representatives of a once larger group of bipedal apes (hominins), the "lesser apes" (hylobatids) are a diverse radiation with numerous extant species. consequently, the lesser apes can provide a valuable evolutionary window onto the possible interactions (e.g., interbreeding) of hominin lineages coexisting in the same time and place. in the present work, we employ chromosomal analyses to verify the hybrid ancestry of an individual (larcon) produced by ... | 2007 | 17717705 |
| life history theory and dental development in four species of catarrhine primates. | dental development was reconstructed in several individuals representing four species of catarrhine primates--symphalangus syndactylus, hylobates lar, semnopithecus entellus priam, and papio hamadryas--using the techniques of dental histology. bar charts assumed to represent species-typical dental development were constructed from these data and estimated ages at first and third molar emergence were plotted on them along with ages at weaning, menarche, and first reproduction from the literature. ... | 2007 | 17706270 |
| mitochondrial dna hypervariable region-1 sequence variation and phylogeny of the concolor gibbons, nomascus. | the still little known concolor gibbons are represented by 14 taxa (five species, nine subspecies) distributed parapatrically in china, myanmar, vietnam, laos and cambodia. to set the stage for a phylogeographic study of the genus we examined dna sequences from the highly variable mitochondrial hypervariable region-1 (hvr-1 or control region) in 51 animals, mostly of unknown geographic provenance. we developed gibbon-specific primers to amplify mtdna noninvasively and obtained >477 bp sequences ... | 2007 | 17455231 |
| the dynamics of hylobatid bipedalism: evidence for an energy-saving mechanism? | when gibbons travel through the forest canopy, brachiation is alternated with short bipedal bouts over horizontal boughs. we know, from previous research, that brachiation is a very efficient locomotor mode that makes use of a pendulum-like exchange of energy, but to date, nothing is known about the dynamics of hylobatid bipedalism. we wondered if gibbons also make use of an efficient gait mechanism during bipedal locomotion. to investigate this, we calculated oscillations of the centre of mass ... | 2006 | 16857866 |
| recurrence plot analysis of nonstationary data: the understanding of curved patterns. | recurrence plots of the calls of the nomascus concolor (western black crested gibbon) and hylobates lar (white-handed gibbon) show characteristic circular, curved, and hyperbolic patterns superimposed to the main temporal scale of the signal. it is shown that these patterns are related to particular nonstationarities in the signal. some of them can be reproduced by artificial signals like frequency modulated sinusoids and sinusoids with time divergent frequency. these modulations are too faint t ... | 2005 | 16196612 |
| effect of diet on dental development in four species of catarrhine primates. | in this study, dental development is described in two pairs of closely related catarrhine primate species that differ in their degree of folivory: 1) hylobates lar and symphalangus syndactylus, and 2) papio hamadryas hamadryas and semnopithecus entellus. growth increments in histological thin sections are used to reconstruct the chronology of dental development to determine how dental development is accelerated in the more folivorous species of each pair. although anterior tooth formation appear ... | 2003 | 12966517 |
| mechanisms of force and power production in unsteady ricochetal brachiation. | brachiators travel by swinging beneath handholds, and it is not obvious how these animals manage to accelerate and decelerate in a horizontal direction, especially when moving rapidly. most previous analyses focused on brachiation in highly constrained laboratory conditions that induced steady-state locomotion. emerging understanding of brachiation suggests that much of gibbon locomotory behavior and morphology must be considered within the context of the complexities of the natural environment: ... | 2003 | 12627531 |
| localized hypoplasia of the primary canine in bonobos, orangutans, and gibbons. | this paper extends observations by lukacs ([1999] am. j. phys. anthropol. 110:351-363; [2001] am. j. phys. anthropol. 116:199-208) of localized hypoplasia of the primary canine (lhpc) among large apes to gibbons, bonobos, and orangutans. lhpc is a roughly circular area of deficient enamel on the labial surface of primary canine teeth which, on current evidence from humans, forms several months after birth due to malnutrition-induced craniofacial osteopenia, leading to crypt fenestration that exp ... | 2003 | 12489137 |
| mechanical energy oscillations of two brachiation gaits: measurement and simulation. | how do arm-swinging apes locomote effectively over a variety of speeds? one way to reduce the metabolic energy cost of locomotion is to transfer energy between reversible mechanical modes. in terrestrial animals, at least two transfer mechanisms have been identified: 1) a pendulum-like mechanism for walking, with exchange between gravitational potential energy and translational kinetic energy, and 2) a spring-like mechanism for running, where the elastic strain energy of stretched muscle and ten ... | 2001 | 11471130 |
| external forces and torques generated by the brachiating white-handed gibbon (hylobates lar). | we compared the kinetics of brachiation to bipedal walking and running. gibbons use pectoral limbs in continuous contact with their overhead support at slow speeds, but exhibit aerial phases (or ricochetal brachiation) at faster speeds. this basic interaction between limb and support suggests some analogy to walking and running. we quantified the forces in three axes and torque about the vertical axis generated by a brachiating white-handed gibbon (hylobates lar) and compared them with bipedal l ... | 2000 | 11002205 |
| histological reconstruction of dental development and age at death in a juvenile gibbon (hylobates lar). | although research on dental development in great apes and modern humans has provided comparative models for life history, growth and development in hominin evolution, almost nothing is known about dental development in their sister group, the hylobatids. hylobatids are of interest because they differ in important life history variables from other catarrhines of similar body mass, and can help to provide more general models for the factors underlying patterns of dental development. this study use ... | 2010 | 9774503 |
| responses of gibbons (hylobates lar) to their mirror images. | nine gibbons (hylobates lar) and one gibbon-siamang crossbreed were observed during exposure to their mirror images over two 30 minute baseline condition periods (mirror off) and four 30 minute treatment condition periods (mirror on). greater frequencies and durations of gazing at the mirror and mirror-contingent behaviors were noted during the reflective conditions than for nonreflective conditions. despite two subjects' apparent use of the mirror to view body parts otherwise not visible to the ... | 1998 | 9651653 |
| a dynamic force and moment analysis system for brachiation. | we describe a transducer system and analysis strategy that allows the determination of dynamic forces and moments applied by an arm-swinging animal during locomotion. we have employed readily available technology and analysis procedures to produce a low-cost but effective system. the solutions to several problems in the design of the system are provided, and the functional characteristics of the system are demonstrated using both an inert pendulum and an actively brachiating gibbon (hylobates la ... | 1997 | 9359890 |
| inter- and intraspecific variation in the diets of sympatric siamang (hylobates syndactylus) and lar gibbons (hylobates lar). | studies of the siamang (hylobates syndactylus continentis) and the lar gibbon (hylobates lar lar) where they co-occur in mainland asia have demonstrated interspecific dietary segregation based on body size and have suggested that observed levels of frugivory represent metabolically based maxima for these species. i studied sympatric groups of siamang (h. s. syndactylus) and lar gibbons (h. l. vestitus) at ketambe in northern sumatra (indonesia) in order to assess the magnitude of within- and bet ... | 1997 | 9375367 |
| immunohistochemical and morphologic features of a cecal adenocarcinoma in a white-handed gibbon (hylobates lar). | | 1995 | 7536983 |
| short dispersal distance of males in a wild white-handed gibbon (hylobates lar) population. | it has long been recognized that in gibbons both sexes disperse from the natal group. however, the fate of dispersed individuals was rarely documented. here we provide the first detailed information on sex differences in dispersal patterns by analyzing the spatial genetic structure of a well-known white-handed gibbon (hylobates lar) population. | 2018 | 29737526 |
| an analysis of white-handed gibbon male song reveals speech-like phrases. | our goal was to document song phrases of the white-handed gibbon (hylobates lar), an asian ape that produces elaborate songs, often in well-coordinated male/female duets. we focused on the male coda, which is produced during vocal turn-taking with one's mate, and particularly its phrases containing rapid spectral and temporal variation, to investigate if modulation rates resemble those of lip-smacking in other nonhuman primates and human speech rhythm. | 2018 | 29508909 |
| the external genitalia of female gibbons, hylobates (h.) lar. | the external genitalia of one perimenarcheal and five adult female white handed-gibbons (hylobates (h.) lar) were examined to clarify their gross anatomy. it was found that the vulval structures were complex and exhibited inter-individual variation in arrangement. this complexity appears to result from an ontogenetic process by which the tissues of the vaginal rim (the labia minora) bud-off and extrude extensions toward the vagina immediately prior and subsequent to menarche. two of these lobula ... | 1992 | 1554106 |
| [kinesiologic studies of brachiation in white-hand gibbons (hylobates lar)]. | | 1984 | 6485502 |
| ontogeny and the evolution of adult body size dimorphism in apes. | this analysis investigates the ontogeny of body size dimorphism in apes. the processes that lead to adult body size dimorphism are illustrated and described. potential covariation between ontogenetic processes and socioecological variables is evaluated. mixed-longitudinal growth data from 395 captive individuals (representing hylobates lar [gibbon], hylobates syndactylus [siamang], pongo pygmaeus [orangutan], gorilla gorilla [gorilla], pan paniscus [pygmy chimpanzee], and pan troglodytes ["commo ... | 1995 | 31924084 |
| lethal territorial aggression in a white-handed gibbon. | during an intergroup conflict an adult male white-handed gibbon (hylobates lar) from one group was attacked and wounded by the adult male of a neighboring group. the wounded male's calling behavior, general activity level, feeding, and participation in territorial defense declined dramatically in the days following the injury as he instead spent long periods resting and tending the wound. the normal and healthy appearance of this male prior to injury, the circumstances of the fight that caused t ... | 1993 | 31936991 |
| reassessment of age of sexual maturity in gibbons (hylobates spp.). | from studies of both wild and captive animals, gibbons are thought to reach sexual maturity at about 6 to 8 years of age, and the siamang (hylobates syndactylus) at about 8 to 9 years. however, a review of the literature reveals that in most cases the exact age of the maturing animals was not known and had to be estimated. this study presents seven case reports on captive gibbons of known age. captive males of the white-cheeked crested gibbon (h. leucogenys leucogenys) and of the siamang (h. syn ... | 1991 | 31952414 |
| hand preferences in captive gorillas, orang-utans and gibbons. | hand preference was assessed in 12 gorillas (gorilla gorilla gorilla), 13 orang-utans (pongo pygmaeus abelii), and 9 gibbons (hylobates lar) by using a floor retrieval task and a mesh retrieval task. hand preference was also assessed in 8 gorillas and 8 orang-utans by using a task involving the unfastening of a hasp. a bipedal requirement during testing (mesh retrieval task) facilitated detection of hand preferences. a significant left-hand preference was found for the gibbons with 6 of 6 gibbon ... | 1990 | 31963993 |
| do line-transect surveys systematically underestimate primate densities in logged forests? | the rate at which social groups of primates are encountered in disturbed rain forest may be biased relative to undisturbed rain forest. a recently reported case study revealed a 25% reduction in postlogging raw encounter rates even though the true density of primates remained at the prelogging level. if biased raw encounter rates are typical of disturbed forests, and if they translate into equally biased line-transect density estimates, results of many comparative surveys might prove misleading ... | 1987 | 31973482 |
| fatal strongyloidiasis in gibbons (hylobates lar). | a 6-year retrospective study of necropsy material from a colony of 200 gibbons showed strongyloidiasis to be the most frequent cause of death (24 cases). clinical signs included diarrhea, constipation, weight loss, paralytic ileus and dyspnea. lesions were most frequent in the gastrointestinal tract and lungs. in the gut there were erosive and ulcerative enteritis associated with adult female parasites and rhabditiform larvae and acute and granulomatous enterocolitis associated with invading fil ... | 1978 | 625867 |
| successful breeding of the laboratory-housed gibbon (hylobates lar). | a cage was developed which included a squeeze wall for easy handling of the gibbon (hylobates lar) and which provided gibbon breeding pairs with privacy from others of the same species. females living in this environment displayed menstrual and vaginal eversion cycles averaging 30 days (range 22-44). twelve compatible pairs produced eight live infants from 15 conceptions in a 33-month period. two full term stillbirths, two abortions, and three current pregnancies accounted for the other seven co ... | 1977 | 853709 |
| one-armed brachiation in gibbons (hylobates lar). | the locomotor and postural behavior of hylobates lar was studied in a seminaturalistic environment at the new york zoological park. a particular locomotor pattern, one-armed brachiation, was observed and filmed. analysis indicated that the occurrence of one-armed brachiation as a preferred locomotor pattern was rare and was limited to the carrying of food. the limb and joint movements of one-armed brachiation closely resembled those of two-armed brachiation with differences occurring in the angu ... | 1982 | 31991983 |
| anti-dnp response in gibbons (hylobates lar). | | 1976 | 955673 |
| are hylobates lar extirpated from china? | the nangunhe nature reserve in southwest yunnan (prc) has long been presumed to be the last stronghold of lar (or white-handed) gibbons (hylobates lar) in china and the likely last place of occurrence of hylobates lar yunnanensis. we conducted a comprehensive survey to assess the status of lar gibbons at nangunhe. we found no visual or auditory evidence of them still residing at the reserve and therefore tentatively conclude that lar gibbons have become extinct in china. it appears that large-sc ... | 2009 | 19644553 |
| cerebral cysticercosis in a white-handed gibbon. | | 1974 | 4426870 |
| relationship of incisor size to diet and anterior tooth use in sympatric sumatran anthropoids. | researchers often relate anthropoid incisor size to diet and ingestive behaviors. it is suggested that primates that frequently consume large, tough foods (i.e., fruits) require large incisors to process these items. this idea has been difficult to test because of a lack of data on anterior tooth use in wild primates, and a lack of understanding concerning the relationships between food properties and ingestive behaviors. the first field study of primate ingestive behaviors has recently been com ... | 1996 | 31918473 |
| pelvic sexual dimorphism among species monomorphic in body size: relationship to relative newborn body mass. | females have larger pelves than males among eutherians to mitigate obstetrical difficulty. this study addresses 3 issues concerning pelvic sexual dimorphism using 8 species that are sexually monomorphic in nonpelvic size: aotus azarae , castor canadensis , dasypus novemcinctus , hylobates lar , saguinus geoffroyi , sciurus carolinensis , sylvilagus floridanus , and urocyon cinereoargenteus . using published data to compute the index of relative newborn body mass (rnbm = [newborn body mass/adult ... | 2016 | 30302031 |
| the forearm and hand musculature of semi-terrestrial rhesus macaques (macaca mulatta) and arboreal gibbons (fam. hylobatidae). part ii. quantitative analysis. | nonhuman primates have a highly diverse locomotor repertoire defined by an equally diverse hand use. based on how primates use their hands during locomotion, we can distinguish between terrestrial and arboreal taxa. the 'arboreal' hand is likely adapted towards high wrist mobility and grasping, whereas the 'terrestrial' hand will show adaptations to loading. while the morphology of the forearm and hand bones have been studied extensively, functional adaptations in the forearm and hand musculatur ... | 2020 | 33011967 |
| the forearm and hand musculature of semi-terrestrial rhesus macaques (macaca mulatta) and arboreal gibbons (fam. hylobatidae). part i. description and comparison of the muscle configuration. | primates live in very diverse environments and, as a consequence, show an equally diverse locomotor behaviour. during locomotion, the primate hand interacts with the superstrate and/or substrate and will therefore probably show adaptive signals linked with this locomotor behaviour. whereas the morphology of the forearm and hand bones have been studied extensively, the functional adaptations in the hand musculature have been documented only scarcely. to evaluate whether there are potential adapta ... | 2020 | 32511764 |
| interactions between lar gibbons and pig-tailed macaques at fruit sources. | interactions are reported between white-handed gibbons (hylobates lar) and pig-tailed macaques (macaca nemestrina) in khao yai national park, thailand, in which gibbons selected ripe fruit from sources before macaques arrived on 4 occasions during june and july of 1989. the macaques foraged near gibbons or from shared fruit sources during 13% of gibbon observation time. gibbons made their presence known in fruit trees when macaques approached on 3 occasions and macaques did not enter fruit trees ... | 1992 | 31948171 |
| mandibular shape variation in mainland and insular hylobatids. | although hylobatids are the most speciose of the living apes, their morphological interspecies and intraspecies variation remains poorly understood. here, we assess mandibular shape variation in two species of hylobates, white-handed (hylobates lar) and black-handed (hylobates agilis) gibbons. using 71 three-dimensional landmarks to quantify mandibular shape, interspecies and intraspecies variation and geographic patterns of mandibular shape are examined in a mixed sex sample of adult h. lar and ... | 2020 | 32696564 |
| are social media reports useful for assessing small ape occurrence? a pilot study from peninsular malaysia. | citizen science-based research has been used effectively to estimate animal abundance and breeding patterns, to monitor animal movement, and for biodiversity conservation and education. here, we evaluate the feasibility of using social media observations to assess the distribution of small apes in peninsular malaysia. we searched for reports of small ape observations in peninsular malaysia on social media (e.g., blogs, facebook, instagram, twitter, youtube, inaturalist, etc.), and also used onli ... | 2020 | 32083333 |
| intestinal parasites and the occurrence of zoonotic giardia duodenalis genotype in captive gibbons at krabokkoo wildlife breeding center, thailand. | intestinal parasitic infections can have an impact on health and growth of wildlife. the current study aims were to determine the prevalence of intestinal parasites and to molecular characterize giardia duodenalis and cryptosporidium spp. in captive gibbons at krabokkoo wildlife breeding center, thailand. fifty-five gibbons, 2 agile- (hylobates agilis), 38 lar- (hylobates lar) and 15 pileated gibbons (hylobates pileatus) were included in this study. fecal samples were collected individually at k ... | 2019 | 31106211 |