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1.
Integr Zool ; 15(1): 79-86, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31305022

RESUMO

Following significant developments in technology, alternative devices have been applied in fieldwork for animal and plant surveys. Thermal-image acquisition cameras installed on unmanned aerial vehicles (UAVs) have been used in animal surveys in the wilderness. This article demonstrates an example of how UAVs can be used in high mountainous regions, presenting a case study on the Sichuan snub-nosed monkey with a detection rate of 65.19% for positive individual identification. It also presents a model that can prospectively predict population size for a given animal species, which is based on combined initial work using UAVs and traditional surveys on the ground. A great potential advantage of UAVs is significantly shortening survey procedures, particularly for areas with high mountains and plateaus, such as the Himalayas, the Qinghai-Tibet Plateau, Hengduan Mountains, the Yunnan-Gui Plateau and Qinling Mountains in China, where carrying out a traditional survey is extremely difficult, so that species and population surveys, particularly for critically endangered animals, are largely absent. This lack of data has impacted the management of endangered animals as well as the formulation and amendment of conservation strategies.


Assuntos
Distribuição Animal , Colobinae/fisiologia , Tecnologia de Sensoriamento Remoto/métodos , Aeronaves , Animais , China , Conservação dos Recursos Naturais , Ecossistema , Densidade Demográfica , Tecnologia de Sensoriamento Remoto/instrumentação
2.
Environ Sci Pollut Res Int ; 26(31): 32374-32384, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31602599

RESUMO

As an endemic primate species with one of the highest priorities in wildlife conservation in China, Sichuan snub-nosed monkeys (Rhinopithecus roxellana) have undergone a sharp decline and range reduction in recent centuries. Here, we used maximum entropy modelling (MaxEnt) integrated with four types of environmental variables, including three biological climate variables (Bio17, precipitation of the driest quarter; Bio6, min. temperature of the coldest month; and Bio2, mean diurnal range), three topographic variables (altitude, slope, and aspect), two anthropogenic variables (Human Footprint Index and human disturbance), and three vegetation-related variables (enhanced vegetation index, normalized difference vegetation index, and Wet Index) to identify the spatial distribution of suitable habitats for Sichuan snub-nosed monkeys in Baihe Nature Reserve (BNR), which is located in the Minshan Mountains. The average training AUC of our model performance is 0.929 ± 0.003. The model predicted 9.6 km2 of high suitability habitats and 14.1 km2 of moderate suitability habitats for Sichuan snub-nosed monkeys, adding up to only 11.7% of the total area of concern for the study in the BNR. The top four variables ranked in the model (altitude, Human Footprint Index, human disturbance, and Bio17) accounted for relative gain contributions of 23.3%, 19.3%, 14.2%, and 13.4%, respectively. The predicted suitable habitats were confined to an altitude range of 1971-3198 m, Human Footprint Index of mainly 3-5 values, low human disturbance (mainly livestock), and precipitation of the driest (or coldest) quarter of 9-22 mm. Additionally, the suitable habitats were mainly distributed in the core zone (36.1%), buffer zone (26.8%), and experimental zone (29.5%). The remaining habitats (7.6%) were distributed in the 0.5-km buffer zone of the reserve border. The predicted suitable habitats indicated limited suitable habitat space for the Sichuan snub-nosed monkeys, with most of the suitable habitat distributed outside the core zone in the BNR. Our findings highlighted that human activities in all three functional zones could be the most negative factor on suitable habitat distribution of Sichuan snub-nosed monkeys in the BNR.


Assuntos
Colobinae/fisiologia , /fisiologia , Altitude , Animais , China , Ecossistema , Atividades Humanas , Humanos
3.
Ecotoxicol Environ Saf ; 180: 679-685, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31146154

RESUMO

Two lichen species, Usnea aciculifera and Usnea luridorufa, were used as biomonitors for the deposition of traffic-related metals in China's Shennongjia National Nature Reserve. The suitability of the two lichen species for use as biomonitors was compared. The health threat to the Sichuan snub-nosed (aka golden) monkey (Rhinopithecus roxellana) from consuming lichen with elevated metal concentrations due to vehicular traffic was then assessed. Lichens, with large surface areas and neither roots nor stomata, efficiently absorb both particulate and gaseous air pollutants. The resulting data was used to assess the effect of heavy metal accumulation on the lichens as well as the health risk imposed on the monkeys as lichen is a primary food source. Lichen samples were collected in the core area of the reserve at three locations of varying traffic intensity. A forth site in the reserve, with no proximate traffic, was used as the control. Results show: (1) lichen from high traffic sites has significantly higher concentrations of Fe, Cd, Pb Zn, and Cr than lichen collected from the control site; (2) vehicular traffic is the primary source of metals in lichen; (3) U. luridorufa collected at high traffic sites displayed decreased photosynthetic efficiency, an indication of stress; (4) intake of Cd and Pb from vehicle emissions in the Shennongjia National Nature Reserve could adversely affect snub-nosed monkey health. This research advances the science of biomonitoring, contributes to environmental protection efforts in China's nature reserves and helps improve food safety for Sichuan snub-nosed monkey, a national treasure of China.


Assuntos
Colobinae/fisiologia , Biomarcadores Ambientais/efeitos dos fármacos , Líquens/efeitos dos fármacos , Metais Pesados/toxicidade , Emissões de Veículos/toxicidade , Poluentes Atmosféricos/metabolismo , Poluentes Atmosféricos/toxicidade , Animais , China , Conservação dos Recursos Naturais , Líquens/metabolismo , Metais Pesados/metabolismo , Medição de Risco
4.
Folia Primatol (Basel) ; 90(3): 190-198, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30889599

RESUMO

We report the first in-depth evidence of targeted mushroom foraging in an Asian colobine. Using direct observations (2010-2018) and camera traps (2008-2018) in the Sebangau Forest, Central Kalimantan, Indonesian Borneo, we show how adult female red langurs (Presbytis rubicunda) are regularly descending to the ground to consume mushrooms. We recorded 82 counts (0.36% of all focal observations, n = 25,502) of the focal adult langur on the ground from direct observations of habituated groups, and 80 independent images/videos of red langurs on the ground were obtained from the camera traps representing 1.12% of total images (n = 7,145). Mushroom consumption took place in 4 families, representing 0.04% of total focal behaviour observations and 24.3% of total time feeding on the ground. From the camera trap photos, red langurs are spending 20% of time on the ground feeding. We speculate that mushrooms could be a supplementary food for adult female langurs as there is an increase in consumption in April and November.


Assuntos
Agaricales , Colobinae/fisiologia , Comportamento Alimentar , Animais , Bornéu , Cercopithecidae/fisiologia , Feminino , Indonésia , Masculino
5.
Primates ; 60(2): 143-153, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30847671

RESUMO

Since its initial discovery in 2010 in the Gaoligong Mountains on the Sino-Myanmar border, there remains no direct information on the feeding habits of the black snub-nosed monkey (Rhinopithecus strykeri). This species is on the verge of extinction, with an estimated remaining population of < 400 individuals. Due to difficulties in following these monkeys across steep mountainous terrain, during 203 observation days (September 2015-January 2017) we recorded 80 h of behavioral records of a wild population (Luoma group). Our preliminary results identified 14 plant species and four lichen species consumed by the monkeys. In addition, we provided the only two captive individuals of this species with a cafeteria diet composed of > 600 wild-collected plant species that were gathered from known R. strykeri habitats to determine which plant species and food items were considered palatable. Our results indicate that the captive monkeys freely consumed young and mature leaves, fruits/seeds, buds, flowers, twigs, and bark from 170 different species of trees, bushes, and herbs representing 76 genera and 41 plant families, as well as 15 species of lichen. All foods consumed by the wild monkeys were also consumed by the captive individuals. Food plants consumed by R. strykeri were found principally in intact subtropical evergreen broadleaf forests and hemlock-broadleaf mixed forests at an altitude of 2200-3000 m. Strict enforcement of habitat protection and access to resources across this elevation zone appear to be essential for the conservation and survivorship of this critically endangered primate.


Assuntos
Colobinae/fisiologia , Conservação dos Recursos Naturais , Dieta/veterinária , Comportamento Alimentar , Animais , China , Florestas , Árvores
6.
Zool Res ; 40(2): 121-128, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-29955030

RESUMO

Knowledge on the home range size of a species or population is important for understanding its behavioral and social ecology and improving the effectiveness of conservation strategies. We studied the home range size of two different-sized groups of golden snub-nosed monkeys (Rhinopithecus roxellana) in Shennongjia, China. The larger group (236 individuals) had a home range of 22.5 km2 from September 2007 to July 2008, whereas the smaller group (62 individuals) occupied a home range of 12.4 km2 from November 2008 to July 2009. Both groups exhibited considerable seasonal variation in their home range size, which was likely due to seasonal changes in food availability and distribution. The home range in any given season (winter, spring, summer, or winter+spring+summer) of the larger group was larger than that of the smaller group. As the two groups were studied in the same area, with the confounding effects of food availability thus minimized, the positive relationship between home range size and group size suggested that scramble feeding competition increased within the larger group.


Assuntos
Comportamento Animal , Colobinae/fisiologia , Comportamento Alimentar , Territorialidade , Animais , China , Atividade Motora , Estações do Ano
7.
Zool Res ; 40(2): 113-120, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30127330

RESUMO

Relaxed open-mouth display serves important social functions in relation to submission, reconciliation, affiliation and reassurance among non-human primate societies; however, quantitative evidence on this behavior remains insufficient among multi-level social groups. From July to November 2016, we examined four potential functions of the relaxed open-mouth display during pairwise, intra-unit social interactions among 18 free-ranging adult and sub-adult golden snub-nosed monkeys (Rhinopithecus roxellana) who belonged to three one-male, multi-female units (OMU) at Dalongtan, Shennongjia National Park, China. Results showed that: compared with no relaxed open-mouth display, (1) the occurrence of displacement by a dominant individual approaching a subordinate was lower and the distance of the subordinate to the approaching dominant was shorter when the subordinate showed open-mouth display; (2) relaxed open-mouth display reduced the probability of continued attack for victims of aggression and allowed victims to achieve closer proximity to the aggressor during post-conflict periods; (3) relaxed open-mouth display by dominant individuals allowed them to achieve closer proximity to subordinates; and (4) the exchange of relaxed open-mouth display had a greater impact on the outcome of interactions than one individual alone giving this signal. These findings suggest that relaxed open-mouth display serves important functions regarding submission, reconciliation, affiliation and reassurance in coordinating social interactions within OMUs in golden snub-nosed monkeys.


Assuntos
Comunicação Animal , Colobinae/fisiologia , Comportamento Social , Animais , Feminino , Masculino , Predomínio Social
8.
Anim Cogn ; 22(1): 71-79, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30460512

RESUMO

Vocal individuality is a prerequisite for individual recognition, especially when visual and chemical cues are not available or effective. Vocalizations encoding information of individual identity have been reported in many social animals and should be particularly adaptive for species living in large and complexly organized societies. Here, we examined the individuality in coo calls of adult male golden snub-nosed monkeys (Rhinopithecus roxellana) living in a large and multilevel society. Coo calls are one of the most frequently occurring call types in R. roxellana and likely serve as the signals for contact maintenance or advertisement in various contexts including group movement, foraging, and resting. From April to October 2016, April to July 2017, and September to October 2017, we recorded a total of 721 coo calls from six adult males in a provisioned, free-ranging group and one adult male in captivity in Shennongjia National Park, China. We selected 162 high-quality recordings to extract 14 acoustic parameters based on the source-filter theory. Results showed that each of all parameters significantly differed among individuals, while pairwise comparisons failed to detect any parameter that was different between all pairs. Furthermore, a discriminant function analysis indicated that the correct assignment rate was 80.2% (cross-validation: 67.3%), greater than expected by chance (14.3%). In conclusion, we found evidence that coo calls of adult male R. roxellana allowed the reliable accuracy of individual discrimination complementarily enhanced by multiple acoustic parameters. The results of our study point to the selective pressures acting on individual discrimination via vocal signals in a highly gregarious forest-living primate.


Assuntos
Colobinae/fisiologia , Individualidade , Vocalização Animal/fisiologia , Acústica , Animais , China , Masculino
9.
Primates ; 60(1): 41-50, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30564972

RESUMO

Knowledge about the feeding ecology and dietary overlap of sympatric primates is essential for understanding how animals avoid or reduce interspecific competition. From April 2014 to March 2015, we investigated the feeding ecologies of two sympatric primates, a hindgut fermenter, the long-tailed macaque (Macaca fascicularis) and a foregut fermenter, the dusky langur (Trachypithecus obscurus obscurus), in a mixed landscape consisting of urban and agro-forested areas and forest fragments in Malaysia. We collected a total of 5570 and 4029 of feeding records for M. fascicularis and T. o. obscurus, respectively, using the 10-min scan sampling method. Food availability and seasonal changes in plant species consumed by both study groups were determined by vegetation surveys carried out across an area of 1.6 ha. A total of 113 and 130 plant species were consumed by M. fascicularis and T. o. obscurus, respectively. Leaves (51%) and fruits (40%) accounted for the majority of the feeding records in T. o. obscurus, whereas fruits (32%) and anthropogenic foods (27%) together with leaves (15%) and insects (6%) accounted for the majority of the feeding records for M. fascicularis. Throughout the year, there were 59 consumed plant species common to both species, and the dietary overlap was the highest for fruits. Although leaves were always more abundant than fruits in our study site, the amount of monthly fruit eating by the two species showed a significant correlation with that of fruit availability. Monthly fruit availability had a positive effect on overall monthly dietary overlap while flower and leaf availability had a negative effect. We showed that fruit was the preferred food resource of two sympatric species with different digestive systems. This could have implications for resource competition, interspecific competition, and niche separation, which should be investigated in more detail.


Assuntos
Colobinae/fisiologia , Dieta , Comportamento Alimentar , Macaca fascicularis/fisiologia , Animais , Feminino , Malásia , Masculino , Estações do Ano , Simpatria
10.
Zool Res ; 40(2): 129-138, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30559334

RESUMO

Golden snub-nosed monkeys (Rhinopithecus roxellana), as typical arboreal group-living Old World monkeys, provide an appropriate animal model to research manual laterality and explore the factors affecting hand preference in nonhuman primates. This study investigated hand preference based on 63 subjects and four spontaneous manual tasks (including unimanual and bimanual feeding and grooming), and assessed the effects of age, gender and type of task on handedness in R. roxellana. A population-level left-handedness was found not only in the bimanual coordinated tasks (bimanual feeding and grooming), but also in one unimanual reaching task (unimanual feeding). There were no significant differences between the sexes in either direction or strength of hand preference among any task. However, a significant difference between adults and juveniles was found in the unimanual feeding task. This is the first report on handedness in unimanual and bimanual feeding tasks that require bipedal posture in wild R. roxellana. Furthermore, this study demonstrated spontaneous feeding tasks reported previously only in the quadrupedal posture in this species, supporting the importance of factors such as posture and task complexity in the evolution of primate manual lateralization.


Assuntos
Envelhecimento , Colobinae/fisiologia , Lateralidade Funcional/fisiologia , Animais , Feminino , Masculino , Fatores Sexuais
11.
Am J Primatol ; 80(12): e22936, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30537389

RESUMO

For non-human primates to optimize their survival chances, sleeping site selection is crucial as they spend much of their time sleeping. We studied sleeping site and tree selection by a group of wild Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in the temperate forests of Baihe Nature Reserve, Sichuan, China, to assess if certain site and tree characteristics were selected. We identified a total of 39 sleeping sites and 111 sleeping trees over a period of 1 year. We compared nine sleeping site and six sleeping tree variables related to the environment, habitat, and vegetation structure. We found that certain characteristics of sleeping sites and sleeping trees predicted their selection by R. roxellana. On a larger spatial scale, sleeping sites were selected based mainly on four factors: canopy height, slope direction, slope gradient, and vegetation type. They also selected sites with trees that were taller and larger, had larger crown diameters and higher bole branches. On a smaller spatial scale, they selected larger trees with larger crown diameters. The selection of these characteristics could be explained in terms of predator avoidance and thermoregulation efficiency, although it was difficult to delineate which was more important. This could be due to some characteristics of R. roxellana, that is, large groups living in temperate climates, which required a balanced strategy for sleeping site and tree selection in order to optimize their survival chances.


Assuntos
Comportamento Animal , Comportamento de Escolha , Colobinae/fisiologia , Sono , Animais , China , Ecossistema , Árvores
12.
Sci Rep ; 8(1): 16183, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30385788

RESUMO

Comparative studies of subspecies under different ecological environments offer insights into intraspecies evolutionary adaptive mechanisms. Golden snub-nosed monkeys (Rhinopithecus roxellana) include three subspecies in China classified mainly by their morphological variations: R. r. roxellana (Sichuan and Gansu province), R. r. qinlingensis (Shaanxi province) and R. r. hubeiensis (Hubei province). These three subspecies live in three isolated area with different environments. Past works focused on the last two subspecies, but little information of habitat and behaviors of the nominated subspecies (R. r. roxellana) is available to date. We conducted a two-year study on the diet, activity budget, home range and social organization of 4 herds of R. r. roxellana, based on a total of 106 days' observation in Laohegou (LHG) Nature Reserve, Sichuan province. By using scan sampling method, our results suggest that the R. r roxellana feeds predominantly on leaves (77.5%), and spends more time feeding (40.0%) and resting (27.0%) while compared to the other two subspecies. Kernel Density Estimation Method based on GPS technology confirms that R. r roxellana has relatively larger home ranges (49.1 km2). The unit size (8.3 ± 3.5 individuals) of R. r roxellana is also smaller. Therefore, it is possible that differences in food availability in relation to habitats have important impacts on the feeding strategy and social system of the golden snub-nosed monkey. These results provide data to further explore intraspecific adaptations of living primates.


Assuntos
Evolução Biológica , Colobinae/fisiologia , Comportamento Alimentar/fisiologia , Animais , China , Colobinae/classificação , Dieta , Ecologia , Ecossistema
13.
Am J Primatol ; 80(11): e22929, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30380174

RESUMO

Climate change threatens endangered species and challenges current conservation strategies. Effective conservation requires vulnerability assessments for species susceptible to climate change and adaptive strategies to mitigate threats associated with climate. In this paper, we used the Maxent to model the impacts of climate change on habitat suitability of Sichuan golden monkey Rhinopithecus roxellana. Our results showed that (i) suitable habitat for Sichuan golden monkey was predicted to decrease by 37% in 2050s under climate change; (ii) the mean elevations of suitable habitat in the 2050s was estimated to shift 160 m higher; (iii) nature reserves protect 62% of current suitable habitat and 56% of future suitable habitat; and (iv) 49% of current suitable habitat was predicted to be vulnerable to future climate change. Given these results, we proposed conservation implications to mitigate the impacts of climate change on Sichuan golden monkey, including adjusting range of national park, establishing habitat corridors, and conducting long-term monitoring.


Assuntos
Mudança Climática , Colobinae/fisiologia , Conservação dos Recursos Naturais/métodos , Refúgio , Distribuição Animal , Animais , China , Ecossistema , Espécies em Perigo de Extinção , Geografia , Parques Recreativos
14.
Am J Primatol ; 80(11): e22914, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30307631

RESUMO

Male-male interactions in mixed-sex groups of social mammals are typically characterized by a mix of hostility and affiliation, as a result of inherent conflicts over mating opportunities, and the costs and benefits of social alliances, co-operative behaviors, and coalitionary defense. In species of nonhuman primates that form all-male groups, it is still unclear how the tradeoffs between the benefits of forming an all-male group and the cost of male-male competition in seeking mating opportunities with females in bisexual groups influence social cohesion in different seasons. Here, we used social network analysis to quantify the impact of reproductive seasonality on social cohesion and clique size of bachelor males residing in an all-male unit (AMU) in wild black-and-white snub-nosed monkeys (Rhinopithecus bieti). These primates are strict seasonal breeders and live in a modular social system composed of a number of one-male units (OMUs) and an associated peripheral AMU. We found that the AMU social network had a significantly lower density, centralization, clustering coefficient, and smaller clique size during the mating season compared to the non-mating period. However, aggression among AMU males during both mating and non-mating periods was low. Our results suggest that network structure topology in male same-sex social units is modulated by seasonal changes. Bachelor males engage in two types of competition to gain reproductive success: first, which is analogous to contest competition, in which bachelor males act aggressively and challenge OMU leader males in an attempt to take over an OMU; and second, which is more analogous to scramble competition, in which bachelor males avoid aggressive interactions and instead engage in sneaky copulations with fertile females. Our work adds to an understanding of the maintenance of all-male groups in species that form a multilevel society.


Assuntos
Agressão , Colobinae/fisiologia , Estações do Ano , Comportamento Social , Animais , Comportamento Competitivo , Copulação , Feminino , Masculino , Reprodução/fisiologia
15.
Primates ; 59(6): 523-530, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30191350

RESUMO

For many primates, sweet taste is palatable and is an indicator that the food contains carbohydrates, such as sugars and starches, as energy sources. However, we have found that Asian colobine monkeys (lutungs and langurs) have low sensitivity to various natural sugars. Sweet tastes are recognized when compounds bind to the sweet taste receptor TAS1R2/TAS1R3 in the oral cavity; accordingly, we conducted a functional assay using a heterologous expression system to evaluate the responses of Javan lutung (Trachypithecus auratus) TAS1R2/TAS1R3 to various natural sugars. We found that Javan lutung TAS1R2/TAS1R3 did not respond to natural sugars such as sucrose and maltose. We also conducted a behavioral experiment using the silvery lutung (Trachypithecus cristatus) and Hanuman langur (Semnopithecus entellus) by measuring the consumption of sugar-flavored jellies. Consistent with the functional assay results for TAS1R2/TAS1R3, these Asian colobine monkeys showed no preference for sucrose or maltose jellies. These results demonstrate that sweet taste sensitivity to natural sugars is low in Asian colobine monkeys, and this may be related to the specific feeding habits of colobine monkeys.


Assuntos
Colobinae/fisiologia , Comportamento Alimentar/fisiologia , Açúcares , Papilas Gustativas/metabolismo , Paladar , Animais , Ásia , Comportamento Animal , Maltose/metabolismo , Boca , Sacarose/metabolismo
16.
Folia Primatol (Basel) ; 89(5): 327-334, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30114703

RESUMO

Reducing the size of food particles is crucial for herbivores. Seasonal dietary changes are known to influence animals' chewing efficiency. Proboscis monkeys (Nasalis larvatus) are foregut fermenters, with a high chewing efficiency allowing them to achieve very fine faecal particles. In this study, we investigated how proboscis monkeys' chewing efficiency varies between wet and dry seasons, hypothesising differences possibly related to diet change. Faecal particle size analysis is an established approach to estimate chewing efficiency in mammalian herbivores. We analysed 113 proboscis monkey faecal samples collected in the Lower Kinabatangan Wildlife Sanctuary, between 2015 and 2017. By following standard sieve analysis protocols, we measured a mean particle size MPS0.025-8 of 0.45 ± 0.14 mm, and confirmed a previous result that proboscis monkeys have a very low faecal MPS. This study highlights a seasonal influence on proboscis monkeys' chewing efficiency, with smaller MPS (better chewing efficiency) during the wet season. During that time of the year, individuals may potentially change their diet, as all faecal samples contained intact seeds. Whether the seasonal MPS difference in proboscis monkeys is smaller than in other colobines due to their "rumination" strategy remains to be investigated.


Assuntos
Colobinae/fisiologia , Fezes , Herbivoria , Mastigação , Tamanho da Partícula , Animais , Bornéu , Dieta , Malásia , Estações do Ano
17.
Primates ; 59(5): 437-448, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30027488

RESUMO

Using direct observations and camera traps at eight sites across Indonesian Borneo we show how red langurs (Presbytis rubicunda) are more terrestrial than previously believed, regularly coming to the ground. This unusual behavior has been found at six of the eight sites surveyed. We find that red langurs come to the ground more frequently in disturbed forests, specifically ones which have been impacted by logging, fire, and hunting, though more data are needed to confirm this as a direct correlation. We also found a trend towards decreased ground use with increased elevation of the habitat. When on the ground, red langurs are predominantly engaged in feeding (50% direct observations, 61% camera traps) and traveling (29% direct observations, 13% camera traps). Red langurs are found on the ground throughout the day, at similar times to activity periods of the apex predator, the Sunda clouded leopard (Neofelis diardi). We suggest that ground use by red langurs could be an adaptation to disturbed forest to exploit additional food sources and to facilitate travel.


Assuntos
Comportamento Animal , Colobinae/fisiologia , Ecossistema , Locomoção , Animais , Bornéu , Feminino , Indonésia , Árvores
18.
Primates ; 59(5): 413-421, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29873035

RESUMO

It has been suggested that social relationships are more likely to be prone to variation in the dispersing sex than the philopatric sex. However, we know less about the dynamics of all-male groups in male-dispersing species than we do about other types of primate groups. We studied male sociality in a captive group of golden snub-nosed monkeys (Rhinopithecus roxellana), which was composed of a one-male unit (OMU, N = 7) and an all-male unit (AMU, N = 7 or 8), in Shanghai Wild Animal Park, China. Using data collected for 6 months, during which there was a demographic change in the AMU and the alpha male was replaced by a newcomer, we found that a dramatic change in social ranks occurred accompanied by elevated aggression following this social upheaval. A proximity-based social network analysis revealed that members did not associate randomly any more but formed differentiated relationships post-upheaval, resulting in three distinct sub-units in the AMU. In terms of inter-unit interactions, significant changes were found in the affiliations between the male juvenile of OMU and AMU individuals. He interacted with AMU individuals randomly and frequently pre-upheaval, but cut down his affiliations and had a preferred partner post-upheaval, who was a member of the dominant male's sub-unit. Our findings suggest that social networks in the dispersing sex are dynamic structures and vary by some demographic change (e.g., individual immigration) in the studied species. We also put forward that individual dominance could be a criterion when the male juvenile chooses partners before he immigrates into a group. In conclusion, the high level of behavioral flexibility of the dispersing sex could be an evolutional strategy and good for individuals' future dispersing life.


Assuntos
Colobinae/fisiologia , Comportamento Social , Agressão , Animais , Animais de Zoológico/fisiologia , China , Masculino , Dinâmica Populacional
19.
Am J Primatol ; 80(6): e22869, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29767431

RESUMO

Vocal signaling represents a primary mode of communication for most nonhuman primates. A quantitative description of the vocal repertoire is a critical step in in-depth studies of the vocal communication of particular species, and provides the foundation for comparative studies to investigate the selective pressures in the evolution of vocal communication systems. The present study was the first attempt to establish the vocal repertoire of free-ranging adult golden snub-nosed monkeys (Rhinopithecus roxellana) based on quantitative methods. During 8 months in Shennongjia National Park, China, we digitally recorded the vocalizations of adult individuals from a provisioned, free-ranging group of R. roxellana across a variety of social-ecological contexts. We identified 18 call types, which were easily distinguishable by ear, visual inspection of spectrograms, and quantitative analysis of acoustic parameters measured from recording samples. We found a great sexual asymmetry in the vocal repertoire size (females produced many more call types than males), likely due to the sex differences in body size and social role. We found a variety of call types that occurred during various forms of agonistic and affiliative interactions at close range. We made inference about the functions of particular call types based on the contexts in which they were produced. Studies on the vocal communication in R. roxellana are particularly valuable since they provide a case about how nonhuman primates, inhabiting forest habitats and forming complex social systems, use their vocalizations to interact with their social and ecological environments.


Assuntos
Colobinae/fisiologia , Comportamento Social , Vocalização Animal/classificação , Animais , China , Feminino , Masculino , Caracteres Sexuais , Espectrografia do Som
20.
Folia Primatol (Basel) ; 89(2): 150-156, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29621754

RESUMO

An all-male band of golden snub-nosed monkeys (Rhinopithecus roxellana) was observed for 3 months in the Qinling Mountains of China, in order to collect data on the frequencies and contextual significance of male-male mounting behaviour. Mounts occurred in a variety of affiliative, dominance-related and sexual contexts, which differed depending upon the ages of the males involved. Mounting behaviour in this group was mainly initiated by adults. Juveniles mounted each other in affiliative contexts (during play and prior to grooming). Adult males mounted subadult and juvenile partners in a greater variety of sociosexual contexts (dominance/rank-related interactions; reconciliation following agonistic encounters, and sometimes as a prelude to receiving grooming). However, subadults and juveniles were never observed to mount adults. In one dyad, involving an adult male and a subadult partner, mounting was more frequent and prolonged, and included bouts of deep pelvic thrusting. Two mounts resulted in anal intromissions and, in 1 case, the subadult partner exhibited seminal emission. Given that the study took place during the annual mating peak period of R. roxellana, it is possible that this unusual male-male sexual activity was related to the absence of mating opportunities for those adults that were excluded from 1-male units.


Assuntos
Colobinae/fisiologia , Comportamento Sexual Animal , Comportamento Social , Animais , China , Asseio Animal , Masculino
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