Suchinda Malaivijitnond

• Chulalongkorn University

Few animals have the cognitive faculties or prehensile abilities needed to eliminate tooth-damaging grit from food surfaces. Some populations of monkeys wash sand from foods when standing water is readily accessible, but this propensity varies within groups for reasons unknown. Spontaneous food-washing emerged recently in a group of long-tailed mac...

Tuberculosis (TB) is the first infectious disease to be screened-out from specified pathogen-free cynomolgus macaques (Macaca fascicularis; Mf) using in human pharmaceutical testing. Being in either latent or active stage after exposure to the Mycobacterium tuberculosis complex (MTBC), the monkey gamma-interferon release assay (mIGRA) was previousl...

Detection and tracking of animals is an important first step for automated behavioral studies in videos. Nowadays, animal tracking is mostly done using deep learning frameworks based on keypoints, which show remarkable results in lab settings with fixed cameras, backgrounds, and lighting. In contrast, multi-animal tracking in the wild is currently...

Few animal species have the cognitive faculties or prehensile abilities needed to eliminate costly tooth-damaging grit from food surfaces. Some populations of monkeys wash sand from foods when standing water is readily accessible, but this propensity varies within groups for reasons unknown. Spontaneous food-washing emerged recently in a group of l...

Few animal species have the cognitive faculties or prehensile abilities needed to eliminate costly tooth-damaging grit from food surfaces. Some populations of monkeys wash sand from foods when standing water is readily accessible, but this propensity varies within groups for reasons unknown. Spontaneous food-washing emerged recently in a group of l...

The archaeological record offers insights into our evolutionary past by revealing ancient behaviour through stone and fossil remains. Percussive foraging is suggested to be particularly relevant for the emergence of tool-use in our lineage, yet early hominin percussive behaviours remain largely understudied compared to flaked technology. Stone tool...

The archaeological record offers insights into our evolutionary past by revealing ancient behaviour through stone and fossil remains. Percussive foraging is suggested to be particularly relevant for the emergence of tool-use in our lineage, yet early hominin percussive behaviours remain largely understudied compared to flaked technology. Stone tool...

Necrophilic behavior (attempted copulation with corpses) has been scarcely reported in non-human primates, especially in the wild. Here is the first case of necrophilic behavior observed in wild stump-tailed macaques in Thailand. Six groups of total N > 460 individuals have been identified and habituated. The corpse of an adult female was found and...

Tuberculosis (TB) is the first infectious disease to be screened-out from specified pathogen-free cynomolgus macaques ( Macaca fascicularis ; Mf) using in human pharmaceutical testing. Being either latent or active stage after exposure to the Mycobacterium tuberculosis complex (MTBC), the monkey gamma-interferon release assay (mIGRA) was previously...

Conservation funding is currently limited; cost-effective conservation solutions are essential. We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value. We assessed field stations’ conservation return on investment and explored the impact of COVID-19. W...

Tuberculosis (TB) is an infectious disease caused by the Mycobacterium tuberculosis complex (Mtbc), which develops from asymptomatic latent TB to active stages. The microbiome was purposed as a potential factor affecting TB pathogenesis, but the study was limited. The present study explored the association between gut-pharyngeal microbiome and TB s...

The detection and management of Mycobacterium tuberculosis complex (MTBC) infection, the causative agent of tuberculosis (TB), in macaques, including cynomolgus macaques (Macaca fascicularis), are of significant concern in research and regions where macaques coexist with humans or other animals. This study explored the utility of the Xpert MTB/RIF...

Few animal species have the cognitive faculties or prehensile abilities needed to eliminate costly tooth-damaging grit from food surfaces. Some populations of monkeys wash sandy foods when standing water is readily accessible, but this propensity varies within groups for reasons unknown. Spontaneous food-washing emerged recently in a group of long-...

Few animal species have the cognitive faculties or prehensile abilities needed to eliminate costly tooth-damaging grit from food surfaces. Some populations of monkeys wash sandy foods when standing water is readily accessible, but this propensity varies within groups for reasons unknown. Spontaneous food-washing emerged recently in a group of long-...

Few animals have the cognitive faculties or prehensile abilities needed to eliminate tooth-damaging grit from food surfaces. Some populations of monkeys wash sand from foods when standing water is readily accessible, but this propensity varies within groups for reasons unknown. Spontaneous food-washing emerged recently in a group of long-tailed mac...

Stone tool use is a rare behavior across nonhuman primates. Here we report the first population of common long‐tailed macaques ( Macaca fascicularis fascicularis ) who customarily used stone tools to open rock oysters ( Saccostrea forskali ) on a small island along the Thai Gulf in Koh Ped (KPE), eastern Thailand. We observed this population severa...

Currently licensed dengue vaccines do not induce long-term protection in children without prior dengue virus exposure. A better understanding of the mechanism by which the immune system prevents dengue virus infection is urgently needed to improve vaccine efficacy. In this study, the induction of protective antibody responses against dengue virus i...

Herpes B virus (BV) is a zoonotic virus which can be transmitted from macaques to humans, which is often associated with high mortality rates. Because macaques often exhibit asymptomatic infections, individuals who come into contact with these animals face unexpected risks of BV infections. A serological test is widely performed to investigate BV i...

Herpes B virus (BV) is a zoonotic virus which can be transmitted from macaques to humans, which is often associated with high mortality rates. Because macaques often exhibit asymptomatic infections, individuals who come into contact with these animals face unexpected risks of BV infections. Serological test is widely performed to investigate BV inf...

The environment has an important effect on the gut microbiota—an essential part of the host’s health—and is strongly influenced by the dietary pattern of the host as these together shape the composition and functionality of the gut microbiota in humans and other animals. This study compared the gut microbiota of Macaca fascicularis fascicularis and...

Surveillance of infectious diseases in free-ranging or wild animals has been widely conducted in many habitat-range countries after the COVID-19 episode. Thailand is located in the center of the distribution range of long-tailed macaques (Macaca fascicularis; Mf) where the animals have both frequent human contact and a high prevalence of human tube...

Thyroid hormones are key modulators of development, as well as mediators of environmental conditions, by regulating developmental processes and metabolism in primates. Hormone measurement in noninvasively collected samples, that is, feces and urine, is a valuable tool for studying the endocrine function of wildlife, and recent studies have demonstr...

Archaeological evidence informs our understanding of the evolution of hominin behaviour. Such evidence is traditionally used to reconstruct hominin activities and intentions. In the Plio-Pleistocene, the presence or absence of specific tools and variation in artefact density is often used to infer foraging strategies, cognitive traits and functiona...

Inadequate calcium intake during childhood and adolescence is detrimental to bone metabolism. Here, we postulated that calcium supplement prepared from tuna bone with tuna head oil should benefit for skeletal development than CaCO3. Forty female 4-week-old rats were divided into calcium-replete diet (0.55% w/w, S1, n = 8) and low-calcium groups (0....

The wild-born long-tailed macaques ( Macaca fascicularis ) were recently recruited and used as breeders for the National Primate Research Center of Thailand, Chulalongkorn University (NPRCT-CU), and changes in their in-depth gut microbiota profiles were investigated. The Oxford Nanopore Technology (ONT) was used to explore full-length 16S rDNA sequ...

The pathways through which primates acquire skills are a central focus of cultural evolution studies. The roles of social and genetic inheritance processes in skill acquisition are often confounded by environmental factors. Hybrid macaques from Koram Island (Thailand) provide an opportunity to examine the roles of inheritance and social learning to...

Intentionally produced sharp-edged stone flakes and flaked pieces are our primary evidence for the emergence of technology in our lineage. This evidence is used to decipher the earliest hominin behavior, cognition, and subsistence strategies. Here, we report on the largest lithic assemblage associated with a primate foraging behavior undertaken by...

We identified tuberculosis in 1,836 macaques from 6 wild rhesus (Macaca mulatta), 23 common long-tailed (M. fascicularis fascicularis), and 6 Burmese long-tailed (M. fascicularis aurea) macaque populations in Thailand. We captured, anesthetized, and collected throat, buccal, and rectal swab specimens from the macaques. We screened swabs for Mycobac...

Cost-effective, and accessible vaccines are needed for mass immunization to control the ongoing coronavirus disease 2019 (COVID-19), especially in low- and middle-income countries (LMIC).A plant-based vaccine is an attractive technology platform since the recombinant proteins can be easily produced at large scale and low cost. For the recombinant s...

Inferring the latent structures of social organisations is a central theme in animal ecology. Sophisticated theoretical frameworks underpin the study of various primate social systems. Single-file movements, defined as serially ordered patterns of animals, reflect intra-group social relationships and provide a key to understanding social structures...

OBJECTIVE To develop a testing algorithm that incorporates multiple assays to evaluate host cellular and humoral immunity and antigen detection concerning Mycobacterium tuberculosis complex (MTBC) infection in captive nonhuman primates. ANIMALS Cohorts of captive-bred and wild-caught macaques from 5 different geographic regions. PROCEDURES Macaques...

Since the outbreak of the coronavirus disease (COVID) pandemic in 2019, the development of effective vaccines to combat the infection has been accelerated. With the recent emergence of highly transmissible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOC), there are concerns regarding the immune escape from vacc...

We report anecdotal evidence for stone-tool-assisted hunting by a non-human primate. Wild Burmese long-tailed macaques ( Macaca fascicularis aurea ) in Laem Son National Park, Thailand, regularly consume crabs, processing them both with and without stone pounding tools. However, stone-tool-assisted capture of crab prey, prior to the processing for...

This study investigated the neuroprotective effects of dihydrotestosterone (DHT), 17β-estradiol (E2), and Pueraria mirifica herb extract (PME; an alternative source of natural estrogens) on the (i) learning and memory in androgen-deficient male rats, and on the hippocampus expression levels of (ii) mRNA of genes associated with synaptic transmissio...

Centromeric satellite DNA (cen-satDNA) consists of highly divergent repeat monomers, each approximately 171 base pairs in length. Here, we investigated the genetic diversity in the centromeric region of two primate species: long-tailed (Macaca fascicularis) and rhesus (Macaca mulatta) macaques. Fluorescence in situ hybridization and bioinformatic a...

Coronavirus disease 2019 (COVID-19) is an acute respiratory illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The prevention of SARS-CoV-2 transmission has become a global priority. Previously, we showed that a protein subunit vaccine that was developed based on the fusion of the SARS-CoV-2 receptor-binding domain (RBD...

Second-order spinal cord excitatory neurons play a key role in spinal processing and transmission of pain signals to the brain. Exogenously-induced change in developmentally-imprinted excitatory neurotransmitter phenotype of these neurons to inhibitory has not yet been achieved. Here we use a subpial dorsal horn-targeted delivery of AAV (adeno-asso...

The constantly emerging severe acute respiratory syndrome‐coronavirus 2 (SARS‐CoV‐2) variants of concern (VOCs) with mutations in the receptor‐binding domain (RBD) spread rapidly and has become a severe public health problem worldwide. Effective vaccines and optimized booster vaccination strategies are thus highly required. Here, the gene encoding...

Gibbons (Family Hylobatidae) are a suitable model for exploring hybridization in pair-living primates as several species form hybrid zones. In Khao Yai National Park, Thailand, white-handed gibbons (Hylobates lar) and pileated gibbons (Hylobates pileatus) are distributed parapatrically and hybridize in a narrow zone. Their phenotypic characteristic...

Male coalition-like formation, recently found in stump-tailed macaques (Macaca arctoides), occurs when several top-ranking males collaboratively guard females to prevent mating with other rival males and actively share secured mating opportunities with their allies. We lack a comprehensive understanding of the proximate mechanisms underlying such m...

Background: We compared the reproductive patterns of wild Indochinese and Sundaic cynomolgus macaques (Mf) exhibiting different levels of genetic admixture with rhesus macaques (Mm). Methods: Ten adult females from each Indochinese (WHM) and Sundaic (KN/KTK) Mf populations, which exhibited 50% and 15% of Mm autosomal SNPs, were selected as focal...

During the past century, macaque bioresources have provided remarkable scientific and biomedical discoveries related to the understanding of human physiology, neuroanatomy, reproduction, development, cognition, and pathology. Considerable progress has been made, and an urgent need has arisen to develop infrastructure and viable settings to meet the...

Background This study examined the population structure of Macaca fascicularis aurea and their genetic relationships with M. f. fascicularis and M. mulatta. Methods The study analyzed 868 RADseq-derived SNPs from samples representing the entire distribution range of M. f. aurea, including their inter- and intraspecific hybrid zones. Results The s...

During the past century, macaque bioresources have provided remarkable scientific and biomedical discoveries related to the understanding of human physiology, neuroanatomy, reproduction, development, cognition, and pathology. Considerable progress has been made, and an urgent need has arisen to develop infrastructure and viable settings to meet the...

Non-invasive techniques for collection of DNA samples of suitable quality and quantity are important for improving the efficiency of genetic wildlife research. The development of a non-invasive method for collection of DNA samples from wild stump-tailed macaques (Macaca arctoides) is described herein. Sterilized polyester rope was cut into 10 cm pi...

Long-tailed macaques ( Macaca fascicularis ), distributed in Southeast Asia, are generally used in biomedical research. At present, the expansion of human communities overlapping of macaques’ natural habitat causes human-macaque conflicts. To mitigate this problem in Thailand, the National Primate Research Center of Thailand, Chulalongkorn Universi...

Pig-tailed macaques are used by coconut farmers in Southeast Asia to harvest coconuts. We assessed the welfare of northern pig-tailed macaques Macaca leonina involved in coconut harvesting in southern Thailand. We interviewed 89 coconut farmers in three provinces focusing on quantifying basic demographics of this trade, i.e., primate species, where...

A Correction to this paper has been published: https://doi.org/10.1007/s10764-021-00222-6

We used the Fecal Immunochemical Occult Blood Test (FIT) kit, a lateral flow immunochromatographic assay specific for human hemoglobin, on cynomolgus monkeys (Macaca fascicularis). We aimed to employ this test to detect gastrointestinal injury in captive animals at the National Primate Research Center of Thailand-Chulalongkorn University (NPRCT-CU)...

The emergence of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected global public health and economy. Despite the substantial efforts, only few vaccines are currently approved and some are in the different stages of clinical trials. As the disease rapidly spreads, an affordable an...

Macaque reproductive patterns range from strictly seasonal breeding to non-seasonal breeding, but factors explaining this variation are not fully understood. Valid reproductive seasonality data are also still lacking for many wild macaque populations because the majority of birth data are from captive animals living outside of their geographic rang...

A substantial portion of the primate genome is composed of non-coding regions, so-called "dark matter", which includes an abundance of tandemly repeated sequences called satellite DNA. Collectively known as the satellitome, this genomic component offers exciting evolutionary insights into aspects of primate genome biology that raise new questions a...

Pueraria mirifica is an endemic Thai plant that has been used for rejuvenation and in the relief of various aging diseases. Puerarin is one of the major isoflavones found in this plant and shows several pharmacological activities in relation to the Thai traditional use of P. mirifica. Therefore, comparative pharmacokinetics of pure puerarin alone a...

The role of sex-specific demography in hybridization and admixture of genetically diverged species and populations is essential to understand the origins of the genomic diversity of sexually reproducing organisms. In order to infer how sex-linked loci have been differentiated undergoing frequent hybridization and admixture, we examined 17 whole-gen...

Cynomolgus monkeys (Macaca fascicularis; MF) are commonly used as nonhuman primate models for pharmaceutical product testing. In their habitat range, monkeys have close contact with humans, allowing the possibility of bidirectional transmission of tuberculosis (TB) between the two species. Although the intradermal tuberculin skin test (TST) is used...

Cynomolgus macaque (Macaca fascicularis) is currently a common animal model for biomedical research. The National Primate Research Center of Thailand, Chulalongkorn University (NPRCT-CU) translocated wild-borne macaques to reared colony for research purposes. At present, no studies focus on fungal microbiome (Mycobiome) of this macaque. The functio...

White-handed gibbons produce loud and acoustically complex songs when interacting with their neighbours or when encountering predators. In both contexts, songs are assembled from a small number of units although their composition differs in context-specific ways. Here, we investigated whether wild gibbons could infer the ‘meaning’ when hearing exem...

The emergence of SARS-CoV-2 in late 2019 and human responses to the resulting COVID-19 pandemic in early 2020 have rapidly changed many aspects of human behavior, including our interactions with wildlife. In this commentary, we identify challenges and opportunities at human-primate interfaces in light of COVID-19, focusing on examples from Asia, an...

Understanding the process and consequences of hybridization is one of the major challenges in evolutionary biology. A growing body of literature has reported evidence of ancient hybridization events or natural hybrid zones in primates, including humans; however, we still have relatively limited knowledge about the pattern and history of admixture b...

The role of sex-specific demography in hybridization and admixture of genetically diverged species and populations is essential to understand the mechanisms forming the genomic diversity of sexually reproducing organisms. In order to infer how sex-linked genetic loci have been differentiated undergoing frequent hybridization and admixture, we exami...

In the original publication of the article the affiliations 1 and 3 were incorrectly published. The correct affiliations are given in this correction.

Male copulation calls sometimes play important roles in sexual strategies, attracting conspecific females or advertising their social status to conspecific males. These calls generally occur in sexually competitive societies such as harem groups and multi-male and multi-female societies. However, the call functions remain unclear because of limited...

Non-invasive techniques for collection of DNA samples of suitable quality and quantity are important for improving the efficiency of genetic wildlife research. The development of a non-invasive method for collection of DNA samples from wild stump-tailed macaques ( Macaca arctoides ) is described herein. Polyester rope was cut into 10 cm pieces, whi...

Cooperation, or the act of benefiting others at the cost of the benefactor's fitness, has been a central issue in evolutionary theory. Non-human animals sometimes show coalitions or male-male cooperation to confront a male rival and challenge the rank hierarchy. Here we observed novel types of coalitions in wild stump-tailed macaques; multiple male...

Throughout the animal kingdom, male colorful ornaments are thought to have evolved through sexual selection by reliably signaling a male’s competitive ability or his superior genetic quality. We tested the function of male ornamentation in wild northern pig-tailed macaque (Macaca leonina) by studying the relationships between male red anogenital co...

Cynomolgus macaques are common across South East Asian countries including Thailand. The National Primate Research Center of Thailand, Chulalongkorn University (NPRCT-CU) captures wild-borne cynomolgus macaque for research use. Limited information is available on the enteric viruses and possible zoonotic infections into or from cynomolgus macaques....

Stone tools in the prehistoric record are the most abundant source of evidence for understanding early hominin technological and cultural variation. The field of primate archaeology is well placed to improve our scientific knowledge by using the tool behaviours of living primates as models to test hypotheses related to the adoption of tools by earl...

Compatibility tests to identify A, B and O alleles are critical for establishing suitable donor‐recipient matches among experimental animals. Using a qPCR‐based SNP probe assay, we have identified A, B, AB, and indeterminate blood group phenotypes in cynomolgus and rhesus macaques. We have hypothesized, albeit without molecular confirmation, that t...

We investigated the early onset of molecular changes in the hippocampus of orchidectomy (ODX)-induced androgen-deficient rats. Transcript levels of the genes associated with loss of synaptic plasticity (Bdnf, Syn, GluN1, α7-nAChR, and M1-mAChR), formation of neurofibrillary tangles (Tau4 and Tau3), and amyloid plaques (App, Adam10, and Bace1), in t...

We studied the social behaviors of western Assamese macaques (Macaca assamensis pelops) at Shivapuri Nagarjun National Park, Nepal from 2014 to 2017 and of eastern Assamese macaques (M. a. assamensis) at Wat Tham Pla, Thailand from 2008 to 2012. The behaviors of both subspecies of M. assamensis were compared to those of Tibetan macaques (M. thibeta...

Stone-hammering behaviour customarily occurs in Burmese long-tailed macaques, Macaca fascicularis aurea , and in some Burmese-common longtail hybrids, M. f. aurea × M. f. fascicularis ; however, it is not observed in common longtails. Facial pelage discriminates these subspecies, and hybrids express variable patterns. It was tested if stone hammeri...

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 agi...

Primate males’ conspicuous coloration has been suggested to signal social status and to have evolved primarily via male-male competition. A less commonly considered mechanism is female mate choice. We tested if the red anogenital coloration exhibited by wild male northern pig-tailed macaques (Macaca leonina) affected female sexual behaviors at Khao...

This project aimed to investigate primate locomotor kinematics noninvasively in the wild. Semi-wild Assamese and stump-tailed macaques were selected for the study, which was performed in Thailand. We investigated their locomotor kinematics and its relationship to habitat use. The macaques’ positional behavior was recorded with two video cameras, an...

The stump-tailed macaque, Macaca arctoides, is the most distinctive in its genus with respect to reproductive anatomy and sexual behavior. Male-male mounting behaviors have been mentioned in many reports; however, ejaculation has not yet been recorded. Herein, we report a very rare case of ejaculation in the context of male-male mounting in wild st...

Knowledge of the macaque ABO blood group system has been critical in the development of nonhuman primates (NHPs) as a translational model. Serving not only as a useful homologue of the disease‐linked ABO system in humans, macaque ABO blood groups must be typed in colonies prior to performing experimental procedures requiring blood transfusion or tr...

The birth of twins, and especially multiple sirehood dizygotic twins, is very rare in Old World monkeys, the only previous record is of a captive rhesus macaque (Macaca mulatta). Here, we report a case of multiple sirehood dizygotic twins among the 114 newborns (0.88%) recorded in a population of semi-wild stump-tailed macaques (M. arctoides) in th...

The priority-of-access model (PoA) assumes that male reproductive success increases with male dominance rank, but the strength of this relationship is predicted to decrease with increasing female synchrony, particularly in seasonally breeding primates. However, genetic paternity studies testing the PoA model have been conducted mostly in nonseasona...

Examining how animals direct social learning during skill acquisition under natural conditions, generates data for examining hypotheses regarding how transmission biases influence cultural change in animal populations. We studied a population of macaques on Koram Island, Thailand, and examined model-based biases during interactions by unskilled ind...

Background Pueraria candollei var. mirifica is a medicinal plant that is promoted as a “Champion Product” by the Government of Thailand. This plant has been reported to relieve postmenopausal symptoms, prevent and reverse bone loss, inhibit the growth of breast cancer, and alleviate cardiovascular diseases in preclinical and clinical studies. Howev...

In multi-male primate groups, it is common for high male dominance rank to be positively related to access to fertile females. However, female reproductive interests and reproductive synchrony can also influence male mating tactics. These mechanisms often remain unknown due to the lack of genetic paternity analysis. We tested the relationship betwe...

The discovery of oil palm (Elaeis guineensis) nut-cracking by wild long-tailed macaques (Macaca fascicularis) is significant for the study of non-human primate and hominin percussive behaviour. Up until now, only West African chimpanzees (Pan troglodytes verus) and modern human populations were known to use stone hammers to crack open this particul...

Objectives: 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...

Vocal duetting occurs when two individuals produce repeated, stereotyped vocalizations, often with alternating contributions. It evolved independently in many pair living taxa. Among hominoids, only hylobatids duet, but little is known about how mated pairs coordinate singing and if individuals adjust their song to spectral and temporal aspects of...

Macaca fascicularis aurea (Burmese long-tailed macaque) is 1 of the 10 subspecies of M. fascicularis. Despite having few morphological differences from other subspecies, a recent phylogeographic study showed that M. f. aurea is clearly distinct genetically from M. f. fascicularis (common long-tailed macaque) and suggests that M. f. aurea experience...

In nonhuman primates, locating and processing hidden or protected foods requires complex manual and cognitive skills. So far, tool-assisted extractive foraging has primarily been studied in great apes, while complex, hierarchically organized manual food processing without tools has received little attention. We describe non-tool-assisted extractive...

Extractive foraging in nonhuman primates may involve different levels of technical complexity in terms of the number of actions that must be performed and the manual dexterity involved. We describe the extractive foraging of caterpillars in wild northern pig-tailed macaques (Macaca leonina) at Khao Yai National Park, Thailand. The study group, obse...

In the past decade, many researchers have published papers about hybridization between long-tailed and rhesus macaques. These previous works have proposed unidirectional gene flow with the Isthmus of Kra as the zoogeographical barrier of hybridization. However, these reports analyzed specimens of unknown origin and/or did not include specimens from...