Genetic Analysis Reveals Dispersal Patterns of Japanese Serow in Two Different Habitats of a Mountainous Region.

Dispersal increases the costs of feeding and predation risk in the new environment and is reported to be biased toward habitats similar to the natal region in some mammals. The benefits and costs of dispersal often differ between sexes, and most mammals show male-biased dispersal in relation to a polygamous mating system. Japanese serow is generally a solitary and monogamous species. However, recent studies have shown that the sociality of serows on Mt. Asama differs between habitat types. In the mountain forests with low forage availability, solitary habits and social monogamy were observed, while, in alpine grasslands, female grouping and social polygyny were observed, which is probably due to abundant forage availability. We investigated the effects of habitat characteristics and sociality on the dispersal of serows using fecal and tissue samples from two different habitats on Mt. Asama. The Fst value between the two areas was significantly positive, and the mean relatedness within areas was significantly higher than that between areas, which suggests limited gene flow and natal habitat-biased dispersal. Bayesian clustering analysis showed unidirectional gene flow from forest to grassland, which was probably due to the high forage availability of the grassland. Analyses of the assignment index and mean relatedness did not show male-biased dispersal, even in the grassland, where serows were polygynous. Thus, polygyny in the grassland is not linked to male-biased dispersal. In summary, our study suggests that dispersal patterns in Japanese serows are affected by habitat rather than social differences.

Novel hypnotics of Japanese traditional herbal medicines to caffeine-induced insomnia in Drosophila by using Newly-developed automated sleep and rhythm analysis system (AutoCircaS).

Sleep in Drosophila was defined in the year 2000 by using Drosophila Activity Monitor (DAM) system. But DAM is very small tube space and one fly per tube is very limited to analyze for fly social behavior. To overcome such demerits of DAM system, we developed a novel automated sleep and rhythm analysis system (AutoCircaS) which monitors and records any behaviors like social mating, sleep, and circadian rhythm in flies (Drosophila) and small fishes medaka (Oryzias latipes) in free space using the time-lapse (one frame per 10 sec) imaging. AutoCircaS can detect the caffeine-induced insomnia in flies in light-dark (LD) and constant dark (DD) conditions. Thus, using the AutoCircaS, we discovered that Japanese traditional herbal medicines, KyushinKannouGan-ki (KKG), NouKassei (NK) as well as, and Sansoninto, significantly improved caffeine-induced insomnia in flies. The data suggest that AutoCircaS is useful for sleep analysis of small animals and screening of new sedative-hypnotics from many origins.

Population genetic structure of raccoons as a consequence of multiple introductions and range expansion in the Boso Peninsula, Japan.

The raccoon (Procyon lotor) is an invasive carnivore that invaded various areas of the world. Although controlling feral raccoon populations is important to reduce serious threats to local ecosystems, raccoons are not under rigid population control in Europe and Japan. We examined the D-loop and nuclear microsatellite regions to identify spatially explicit and feasible management units for effective population control and further range expansion retardation. Through the identification of five mitochondrial DNA haplotypes and three nuclear genetic groups, we identified at least three independent introductions, range expansion, and subsequent genetic admixture in the Boso Peninsula. The management unit considered that two were appropriate because two populations have already genetic exchange. Furthermore, when taking management, we think that it is important to monitor DNA at the same time as capture measures for feasible management. This makes it possible to determine whether there is a invasion that has a significant impact on population growth from out of the unit, and enables adaptive management.

Saffron ameliorated motor symptoms, short life span and retinal degeneration in Parkinson's disease fly models.

Parkinson's disease (PD) is a common neurodegenerative disorder with motor symptoms linked to the loss of dopaminergic neurons in the brain. α-Synuclein is an aggregation-prone neural protein that plays a role in the pathogenesis of PD. In our previous paper, we found that saffron; the stigma of Crocus sativus Linné (Iridaceae), and its constituents (crocin and crocetin) suppressed aggregation of α-synuclein and promoted the dissociation of α-synuclein fibrils in vitro. In this study, we investigated the effect of dietary saffron and its constituent, crocetin, in vivo on a fly PD model overexpressing several mutant α-synuclein in a tissue-specific manner. Saffron and crocetin significantly suppressed the decrease of climbing ability in the Drosophila overexpressing A30P (A30P fly PD model) or G51D (G51D fly PD model) mutated α-synuclein in neurons. Saffron and crocetin extended the life span in the G51D fly PD model. Saffron suppressed the rough-eyed phenotype and the dispersion of the size histogram of the ocular long axis in the eye of A30P fly PD model. Saffron had a cytoprotective effect on a human neuronal cell line with α-synuclein fibrils. These data showed that saffron and its constituent crocetin have protective effects on the progression of PD disease in animals in vivo and suggest that saffron and crocetin can be used to treat PD.

Female chimpanzees giving first birth in their natal group in Mahale: attention to incest between brothers and sisters.

Chimpanzee societies generally show male philopatry and female dispersal. However, demographic data on wild chimpanzee societies from long-term study sites have revealed that some females give birth in their natal group (i.e., "remaining females"). Here, we report two remaining females in the M group in Mahale, Tanzania, and compare their cases with previous reports to explore the social and ecological factors that lead to females remaining in their natal group. The results revealed that neither the social traits of the remaining females nor the ecological factors they experienced showed a coherent trend. However, we found multiple, non-mutually exclusive potential factors that may influence the decision by females to remain in their natal group: a decrease in indirect feeding competition, support from mothers or allomothers in the care of offspring and in aggressive interactions with other individuals, close relationships with the other remaining females, and a short adolescent infertility period. Additionally, we observed a natal female copulating with her older brother, which was the first observation of brother-sister incest in Mahale. Although DNA analysis revealed that her infant was not a product of inbreeding, the pair copulated frequently in the latter half of her estrus period, suggesting that they did not avoid incest behaviorally to avoid inbreeding. Furthermore, there was no hard evidence that the remaining female avoided mating with her maternal brother, suggesting that incest avoidance may not be a proximate factor responsible for female dispersal.

Extensive splicing changes in an ALS/FTD transgenic mouse model overexpressing cytoplasmic fused in sarcoma.

Mutations in RNA-binding proteins (RBPs) such as TAR DNA-binding protein 43 (TDP-43) and fused in sarcoma (FUS) are associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Recent evidence suggests that RNA dysregulation mediated by aberrant RBPs may play a critical role in neurodegeneration, but the underlying molecular mechanisms are largely unknown. In this study, we performed whole transcriptome profiling of various brain tissues of a transgenic (Tg) mouse model of ALS/FTD overexpressing the exogenous nuclear localization signal deletion mutant of human FUS (ΔNLS-FUS) to investigate changes associated with the early stages of ALS/FTD. Although there were not many differences in expression profiles between wild-type and Tg mice, we found that Sema3g was significantly upregulated in the frontal cortex and hippocampus of Tg mice. Interestingly, analysis of alternative splicing events identified widespread exons that were differentially regulated in Tg mice in a tissue-specific manner. Our study thus identified aberrant splicing regulation mediated by mutant FUS during the early stages of ALS/FTD. Targeting this aberrant splicing regulation represents a potential therapeutic strategy for ALS/FTD.

Improving the standards for gut microbiome analysis of fecal samples: insights from the field biology of Japanese macaques on Yakushima Island.

Fecal DNA-based 16S ribosomal RNA (rRNA) gene sequencing using next-generation sequencers allows us to understand the dynamic gut microbiome adaptation of animals to their specific habitats. Conventional techniques of fecal microbiome analysis have been developed within the broad contexts defined by human biology; hence, many of these techniques are not immediately applicable to wild nonhuman primates. In order to establish a standard experimental protocol for the analysis of the gut microbiomes of wild animals, we selected the Japanese macaques (Macaca fuscata yakui) on Yakushima Island. We tested different protocols for each stage of fecal sample processing: storage, DNA extraction, and choice of the sequencing region in the bacterial 16S rRNA gene. We also analyzed the gut microbiome of captive Japanese macaques as the control. The comparison of samples obtained from identical macaques but subjected to different protocols showed that the tested storage methods (RNAlater and lysis buffer) produced effectively the same composition of bacterial operational taxonomic units (OTUs) as the standard frozen storage method, although the relative abundance of each OTU was quantitatively affected. Taxonomic assignment of the detected bacterial groups was also significantly affected by the region being sequenced, indicating that sequencing regions and the corresponding polymerase chain reaction (PCR) primer pairs for the 16S rRNA gene should be carefully selected. This study improves the current standard methods for microbiome analysis in wild nonhuman primates. Japanese macaques were shown to be a suitable model for understanding microbiome adaptation to various environments.

Reproductive success of two male morphs in a free-ranging population of Bornean orangutans.

The reproductive success of male primates is not always associated with dominance status. For example, even though male orangutans exhibit intra-sexual dimorphism and clear dominance relationships exist among males, previous studies have reported that both morphs are able to sire offspring. The present study aimed to compare the reproductive success of two male morphs, and to determine whether unflanged males sired offspring in a free-ranging population of Bornean orangutans, using 12 microsatellite loci to determine the paternity of eight infants. A single flanged male sired most of the offspring from parous females, and an unflanged male sired a firstborn. This is consistent with our observation that the dominant flanged male showed little interest in nulliparous females, whereas the unflanged males frequently mated with them. This suggests that the dominant flanged male monopolizes the fertilization of parous females and that unflanged males take advantage of any mating opportunities that arise in the absence of the flanged male, even though the conception probability of nulliparous females is relatively low.

Effects of saffron and its constituents, crocin-1, crocin-2, and crocetin on α-synuclein fibrils.

Saffron, the stigma of Crocus sativus Linné (Iridaceae family), has been known to inhibit aggregation of ß-amyloid, a nerve tissue protein. α-Synuclein (αS) is a 140-amino acid protein found abundantly in various regions of the brain. Its abnormal aggregation and accumulation in nerve tissue are said to cause neurodegenerative diseases such as Parkinson's disease, Lewy body dementia, and multiple-system atrophy. This study (part of this study was presented at the 137th Annual Meeting of the Pharmaceutical Society of Japan) examined the effects of saffron, its constituents (crocin-1, crocin-2, crocetin, and safranal), and crocetin structural analogs (hexadecanedioic acid, norbixin, and trans, trans-muconic acid) on αS aggregation, and αS fibril dissociation. Saffron dose-dependently inhibited αS aggregation and dissociated αS fibrils by thioflavin T fluorescence assay. These effects were observed by transmission electron microscopy, which showed reduced and shortened αS fibrils. Crocin-1, crocin-2, and crocetin showed anti-aggregation and fibril dissociation effects, with crocetin being the most potent. The effects of norbixin were weaker than those of crocetin, and the other crocetin structural analogs showed no effects. These results show that saffron and its constituents (crocin-1, crocin-2, and crocetin) can be effective in preventing and treating diseases caused by abnormal αS aggregation.

Identification and molecular characterization of novel primate bocaparvoviruses from wild western lowland gorillas of Moukalaba-Doudou National Park, Gabon.

Bocaparvoviruses have been studied extensively owing to their ability to cause respiratory illness or gastroenteritis in humans. Some bocaparvoviruses have been detected in non-human primates (gorillas and chimpanzees), but the diversity and evolution of these viruses are not fully understood. In this study, we collected 107 fecal samples from wild western lowland gorillas in Moukalaba-Doudou National Park in Gabon to investigate the presence of bocaparvoviruses. Using a combination of pan-bocaparvovirus PCR and individual identification by microsatellite genotyping, we found that two samples from two apparently healthy infant gorillas were positive for bocaparvovirus. Sequencing and phylogenetic analyses revealed that the two gorilla bocaparvovirus strains are nearly identical and are closely related to viruses in the species Primate bocaparvovirus 2 (with 86.0% nucleotide identity to a human bocavirus 2 isolate). To our knowledge, this is the first report showing the presence of a non-human primate bocaparovirus within Primate bocaparvovirus 2. Our findings provide novel insights into the diversity and evolution of bocaparvoviruses and highlight the importance of surveying these viruses for the safe management of gorilla-based ecotourism.

Genes, social transmission, but not maternal effects influence responses of wild Japanese macaques (Macaca fuscata) to novel-object and novel-food tests.

Using long-term maternal pedigree data, microsatellite analysis, and behavioral tests, we examined whether personality differences in wild Japanese macaques (Macaca fuscata) are associated with additive genetic effects, maternal influences, or belonging to a particular social group. Behaviors elicited by novel-object tests were defined by a component related to caution around novel-objects (Ob-PC1) and behaviors elicited by novel food-tests were defined by correlated components related to consummatory responses (Fo-PC1) and caution around novel foods (Fo-PC2). The repeatability of Ob-PC1 was modest and not significant; the repeatabilities of Fo-PC1 and Fo-PC2 were moderate and significant. Linear mixed effects models found that sex, age, sex × age, provisioning, trial number, date, time of day, season, and distance to the closest monkey were not related to personality. Linear mixed effects models of females older than 2 years found that high rank was associated with greater caution around novel objects. Linear models were used to determine whether sex, age, group membership, maternal kinship, or relatedness had independent effects on the personality similarity of dyads. These analyses found that pairs of macaques that lived in the same group were less similar in their caution around novel objects, more closely related pairs of macaques were more similar in their tendency to eat novel food, and that pairs of macaques in the same group were more similar in how cautious they were around novel foods. Together, these findings suggest that personality in this population of wild monkeys was driven by rank, genetic effects, and group effects, the latter possibly including the need to exploit different niches in the environment.

Agarwood Inhibits Histamine Release from Rat Mast Cells and Reduces Scratching Behavior in Mice: Effect of Agarwood on Histamine Release and Scratching Behavior.

OBJECTIVES: This study was conducted to clarify the effects of agarwood on histamine release from mast cells in rats and on the scratching behaviors in mice. METHODS: Histamine release from rat mast cells induced by compound 48/80 or concanavalin A (Con A) and compound 48/80-induced scratching behavior in mice were examined to investigate the effects of agarwood. The hyaluronidase activity and the 3',5'-cyclic adenosine monophosphate (cAMP) levels in mast cells were examined to investigate the mechanisms for the inhibition of histamine release. The correlation between the inhibitory effects of agarwood on histamine release and the content of its typical ingredients, a 2-(2-phenylethyl)chromone derivatives, was analyzed using thin-layer chromatography. RESULTS: Agarwood showed an inhibitory effect on mast-cell histamine release induced by compound 48/80 or Con A without any effect on hyaluronidase activity; this effect involves an increase in the cAMP levels in mast cells. Oral administration of agarwood showed an inhibitory effect on compound 48/80-induced scratching behavior in mice. The inhibitory effects of agarwood on histamine release were quite different, depending on the area where the agarwood was produced, its quality, and its market price. No correlation was found between the inhibitory effects of agarwood on histamine release and the typical ingredients of agarwood, which are 2-(2-phenylethyl)chromone derivatives. CONCLUSION: These results show that agarwood inhibits histamine release from mast cells partially through an increase in the cAMP levels in cells. We suggest that some active ingredients of agarwood must be effective on oral intake and that agarwood can be used to treat patients with a number of conditions, including urticaria, atopic dermatitis, and bronchial asthma, in which an increase in histamine release occurs. Differences in the pharmacological effects of this crude drug among markets may provide important information for the quality control of this herbal medicine.

The active zone protein CAST regulates synaptic vesicle recycling and quantal size in the mouse hippocampus.

Synaptic efficacy is determined by various factors, including the quantal size, which is dependent on the amount of neurotransmitters in synaptic vesicles at the presynaptic terminal. It is essential for stable synaptic transmission that the quantal size is kept within a constant range and that synaptic efficacy during and after repetitive synaptic activation is maintained by replenishing release sites with synaptic vesicles. However, the mechanisms for these fundamental properties have still been undetermined. We found that the active zone protein CAST (cytomatrix at the active zone structural protein) played pivotal roles in both presynaptic regulation of quantal size and recycling of endocytosed synaptic vesicles. In the CA1 region of hippocampal slices of the CAST knockout mice, miniature excitatory synaptic responses were increased in size, and synaptic depression after prolonged synaptic activation was larger, which was attributable to selective impairment of synaptic vesicle trafficking via the endosome in the presynaptic terminal likely mediated by Rab6. Therefore, CAST serves as a key molecule that regulates dynamics and neurotransmitter contents of synaptic vesicles in the excitatory presynaptic terminal in the central nervous system.

Validity and reliability of the Japanese version of the FIM + FAM in patients with cerebrovascular accident.

BACKGROUND AND AIM: The study aim was to investigate the validity and reliability of the Functional Independence Measure and Functional Assessment Measure (FIM + FAM), which is unfamiliar in Japan, by using its Japanese version (FIM + FAM-j) in patients with cerebrovascular accident (CVA). MATERIAL AND METHODS: Forty-two CVA patients participated. Criterion validity was examined by correlating the full scale and subscales of FIM + FAM-j with several well-established measurements using Spearman's correlation coefficient. Reliability was evaluated by internal consistency (tested by Cronbach's alpha coefficient) and intra-rater reliability (tested by Kendall's tau correlation coefficient). RESULTS: Good-to-excellent criterion validity was found between the full scale and motor subscales of the FIM + FAM-j and the Barthel Index, National Institutes of Health Stroke Scale, modified Rankin Scale, and lower extremity Brunnstrom Recovery Stage. High internal consistency was observed within the full-scale FIM + FAM-j and the motor and cognitive subscales (Cronbach's alphas were 0.968, 0.954, and 0.948, respectively). Additionally, good intra-rater reliability was observed within the full scale and motor subscales, and excellent reliability for the cognitive subscales (taus were 0.83, 0.80, and 0.98, respectively). CONCLUSION AND SIGNIFICANCE: This study showed that the FIM + FAM-j demonstrated acceptable levels of validity and reliability when used for CVA as a measure of disability.

Estimation of chimpanzee community size and genetic diversity in Kahuzi-Biega National Park, Democratic Republic of Congo.

A small chimpanzee habitat in the montane forest of Kahuzi-Biega National Park, Democratic Republic of Congo, is connected with the lowland forest of this park through a corridor, which is affected by human encroachment. To assess the conservation status of the chimpanzee population in this small habitat, we estimated the size of the community and evaluated its genetic diversity by using 279 fecal samples collected in the montane forest of Kahuzi. Using autosomal microsatellite (or short tandem repeat, STR) loci, we identified 32 individuals, comprising 19 females and 13 males. Samples from 24 individuals were collected at least twice and a genetic mark-recapture analysis estimated that the community size was 36 (range: 32-42). Data on nest site sharing confirmed that all the samples belonged to the same community. Nest site sharing information may be useful in population studies of unhabituated chimpanzees. The genetic structure and diversity of the 32 genotyped individuals was assessed using Y-chromosomal short tandem repeat (Y-STR) loci and mitochondrial D-loops. One dominant Y-STR haplotype was found, whereas there was no dominant haplotype in the mitochondrial region, reflecting a female-biased dispersal pattern, which is typical of chimpanzees. The genetic diversity for three markers in Kahuzi chimpanzees was comparable to that in other eastern chimpanzee populations. A relatively high heterozygosity and negative inbreeding coefficient (FIS ) for STR loci suggests that the study community belongs to an outbreeding chimpanzee population. These findings suggest that individuals of the study community may have reproductive contact with other chimpanzee individuals from neighboring communities in Kahuzi-Biega National Park, at least in the recent past. Am. J. Primatol. 77:1015-1025, 2015. © 2015 Wiley Periodicals, Inc.

Sharing fruit of Treculia africana among western gorillas in the Moukalaba-Doudou National Park, Gabon: preliminary report.

We report the first 18 observed cases of fruit (Treculia africana) transfer among western lowland gorillas (Gorilla gorilla gorilla) in Moukalaba-Doudou National Park, Gabon. The fruit transfer occurred during our observations of a habituated group of gorillas in 2010 and 2013. Pieces of the fruits were transferred among adults and immatures, and three cases involved a silverback male. Once an individual picked up a fallen fruit of Treculia africana, other members of the group approached the possessor, who laid pieces of the fruits nearby and tolerated the others getting them. Agonistic interaction was rarely observed between the possessor and the non-possessor. Only the silverback male seemed to force another gorilla, a subadult male, to relinquish the fruit on the ground. He tolerated an adult female taking a piece of fruit on his leg and copulated with her on the following days. From these preliminary observations, most interactions over the fruit of Treculia africana among western gorillas in Moukalaba were not active transfer by the possessor but probably passive sharing. They were not only interpreted as a means of acquiring foraging skills by immatures (Nowell and Fletcher 2006) but also similar to behaviors observed in chimpanzees and bonobos in various social contexts.

The planar cell polarity protein Vangl2 bidirectionally regulates dendritic branching in cultured hippocampal neurons.

BACKGROUND: Van Gogh-like (Vangl) 2 is a planar cell polarity (PCP) protein that regulates the induction of polarized cellular and tissue morphology during animal development. In the nervous system, the core PCP signaling proteins have been identified to regulate neuronal maturation. In axonal growth cones, the antagonistic interaction of PCP components makes the tips of filopodia sensitive to guidance cues. However, the molecular mechanism by which the PCP signaling regulates spine and dendritic development remains obscure. FINDINGS: Here we explored the finding that a loss of function of Vangl2 results in a significant reduction in spine density and complexity of dendritic branching. In spite of a previous report, in which the Vangl2 C-terminal TSV motif was shown to be required for the interaction with PSD-95 and the C-terminal intracellular domain was shown to associate with N-cadherin, overexpression of deletion mutants (Vangl2-∆TSV and Vangl2-∆C) had little effect on spine density. However, when an N-terminal region deletion mutant was overexpressed, spine density was slightly down-regulated. Intriguingly, the deletion mutants had a more potent effect on dendritic branching, such that the deletion of the N-terminal region reduced dendritic branching, whereas deletion of the C-terminal region increased it. CONCLUSIONS: Based on these results, Vangl2, a core PCP signaling pathway component, appears to have a functional role in neural complex formation. Especially in the case of dendritic branching, Vangl2 serves as a molecular hub to regulate neural morphology in opposite directions.

Mycophagy among Japanese macaques in Yakushima: fungal species diversity and behavioral patterns.

Mycophagy (fungus-feeding) by Japanese macaques (Macaca fuscata yakui) in Yakushima has been observed by many researchers, but no detailed information is available on this behavior, including which fungal species are consumed. To provide a general description of mycophagy and to understand how and whether macaques avoid poisonous fungi, we conducted behavioral observation of wild Japanese macaques in Yakushima and used molecular techniques to identify fungal species. The results indicate that the diet of the macaques contains a large variety of fungal species (67 possible species in 31 genera), although they compose a very small portion of the total diet (2.2% of annual feeding time). Fungi which were eaten by macaques immediately after they were picked up were less likely to be poisonous than those which were examined (sniffed, nibbled, carefully handled) by macaques. However, such examining behaviors did not appear to increase the macaques' abilities to detect poisonous fungi. Fungi that were only partially consumed included more poisonous species than those fully consumed with/without examining behavior, yet this was not significant. Taste, therefore, might also play an important role in discriminating poisonous from non-poisonous.

Analgesic Effects of Toad Cake and Toad-cake-containing Herbal Drugs: Analgesic effects of toad cake.

OBJECTIVES: This study was conducted to clarify the analgesic effect of toad cake and toad-cake-containing herbal drugs. METHODS: We counted the writhing response of mice after the intraperitoneal administration of acetic acid as a nociceptive pain model and the withdrawal response after the plantar surface stimulation of the hind paw induced by partial sciatic nerve ligation of the mice as a neuropathic pain model to investigate the analgesic effect of toad cake and toad-cake-containing herbal drugs. A co-treatment study with serotonin biosynthesis inhibitory drug 4-chloro- DL-phenylalanine methyl ester hydrochloride (PCPA), the catecholamine biosynthesis inhibitory drug α-methyl- DL-tyrosine methyl ester hydrochloride (AMPT) or the opioid receptor antagonist naloxone hydrochloride was also conducted. RESULTS: Analgesic effects in a mouse model of nociceptive pain and neuropathic pain were shown by oral administration of toad cake and toad-cake-containing herbal drugs. The effects of toad cake and toad-cake-containing herbal drugs disappeared upon co-treatment with PCPA, but not with AMPT or naloxone in the nociceptive pain model; the analgesic effect of toad-cake-containing herbal drugs also disappeared upon co-treatment with PCPA in the neuropathic pain model. CONCLUSION: Toad cake and toad-cake-containing herbal drugs have potential for the treatments of nociceptive pain and of neuropathic pain, such as post-herpetic neuralgia, trigeminal neuralgia, diabetic neuralgia, and postoperative or posttraumatic pain, by activation of the central serotonin nervous system.

Assessment of landscape-scale distribution of sympatric great apes in African rainforests: concurrent use of nest and camera-trap surveys.

Information on the distribution and abundance of sympatric great apes (Pan troglodytes troglodytes and Gorilla gorilla gorilla) are important for effective conservation and management. Although much research has been done to improve the precision of nest-surveys, trade-offs between data-reliability and research-efficiency have not been solved. In this study, we used different approaches to assess the landscape-scale distribution patterns of great apes. We conducted a conventional nest survey and a camera-trap survey concurrently, and checked the consistency of the estimates. We divided the study area (ca. 500 km²), containing various types of vegetation and topography, into thirty 16-km² grids (4 km × 4 km) and performed both methods along 2-km transects centered in each grid. We determined the nest creator species according to the definitions by Tutin & Fernandez [Tutin & Fernandez, 1984, Am J Primatol 6:313-336] and estimated nest-site densities of each species by using the conventional distance-sampling approach. We calculated the mean capture rate of 3 camera traps left for 3 months at each grid as the abundance index. Our analyses showed that both methods provided roughly consistent results for the distribution patterns of the species; chimpanzee groups (parties) were more abundant in the montane forest, and gorilla groups were relatively homogeneously distributed across vegetation types. The line-transect survey also showed that the number of nests per nest site did not vary among vegetation types for either species. These spatial patterns seemed to reflect the ecological and sociological features of each species. Although the consistent results may be largely dependent on site-specific conditions (e.g., high density of each species, distinct distribution pattern between the two species), conventional nest-surveys and a subsequent check of their consistency with independent estimates may be a reasonable approach to obtain certain information on the species distribution patterns. Further analytical improvement is necessary for camera-traps to be considered a stand-alone method.