The field research on five black crested gibbon groups, recently performed at Dazhaizi, Mr. Wuliang, Central Yunnan, China, showed that all groups in the local population consisted of one adult male, two adult females...The field research on five black crested gibbon groups, recently performed at Dazhaizi, Mr. Wuliang, Central Yunnan, China, showed that all groups in the local population consisted of one adult male, two adult females and 2 - 5 sub-adults, juveniles and itfants. The mean group size was 6.2 in August 2003 and 6.4 in August 2005. Two subadult males disappeared from their natal home range and three newborns were given birth in Group 3 （G3） and G4 during this study. The two adult females in G1, G2 and G3 gave births and/or carried babies but at different times. There was no aggressive or dominating behaviour observed between the two adult females. One floating female was first seen in G3＇s territory on April 15, 2005. The two resident females interrupted her duet with adult male and chased her. We did not observe adult male chased this floating female and she left G3＇s territory 10 days later. Sub-adult males often kept distance with the family, and they often sang solo bouts in their natal territory before they dispersed. The sub-adult males and females dispersed from natal territory and two adult resident females rejected the third one, which might were the reasons why the black gibbon groups were polygyny in Dazhaizi.展开更多
We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons(Nomascus concolor)using social network analysis.The spatial proximity changed seasonally an...We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons(Nomascus concolor)using social network analysis.The spatial proximity changed seasonally and was affected by temperature and rainfall.Preferred proximity association was not distributed randomly among individuals.Kinship was one explanation for the social structure,as offspring preferred to maintain close proximity with their mothers.The proximity of infants to mothers decreased with age,and independent offspring had lower proximity to mothers than dependent ones.We found that the adult male had different proximity relationships with two different adult females.The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group.Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences.Temperature influenced group proximity association,with individual proximity increasing in the cold months and decreasing in the hot months.Group proximity decreased in months with higher anthropogenic disturbance.展开更多
We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons (Nomascus concolor) using social network analysis. The spatial proximity changed seasonally...We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons (Nomascus concolor) using social network analysis. The spatial proximity changed seasonally and was affected by temperature and rainfall. Preferred proximity association was not distributed randomly among individuals. Kinship was one explanation for the social structure, as offspring preferred to maintain close proximity with their mothers. The proximity of infants to mothers decreased with age, and independent offspring had lower proximity to mothers than dependent ones. We found that the adult male had different proximity relationships with two different adult females. The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group. Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences. Temperature influenced group proximity association, with individual proximity increasing in the cold months and decreasing in the hot months. Group proximity decreased in months with higher anthropogenic disturbance.展开更多
Gibbons and siamangs （Hylobatidae） are well-known for their rapid chromosomal evolution,which has resulted in high speciation rate within the family.On the other hand,distinct karyotypes do not prevent speciation,al...Gibbons and siamangs （Hylobatidae） are well-known for their rapid chromosomal evolution,which has resulted in high speciation rate within the family.On the other hand,distinct karyotypes do not prevent speciation,allowing interbreeding between individuals in captivity,and the unwanted hybrids are ethically problematic as all gibbon species are endangered or critically endangered.Thus,accurate species identification is crucial for captive breeding,particularly in China where studbooks are unavailable.Identification based on external morphology is difficult,especially for hybrids,because species are usually similar in appearance.In this study,we employed G-banding karyotyping and fluorescence in situ hybridization （FISH） as well as a PCR-based approach to examine karyotypic characteristics and identify crested gibbons of the genus Nomascus from zoos and nature reserves in China.We characterized and identified five karyotypes from 21 individuals of Nomascus.Using karyotypes and mitochondrial and nuclear genes,we identified three purebred species and three hybrids,including one F2 hybrid between N.gabriellae and N.siki.Our results also supported that N.leucogenys and N.siki shared the same inversion on chromosome 7,which resolves arguments from previous studies.Our results demonstrated that both karyotyping and DNA-based approaches were suitable for identifying purebred species,though neither was ideal for hybrid identification.The advantages and disadvantages of both approaches are discussed.Our results further highlight the importance of animal ethics and welfare,which are critical for endangered species in captivity.展开更多
The cao vit gibbon is a critically endangered species.Only approximately 110 individuals remain in degraded karst forest along the China-Vietnam border.Karst forest is unusual gibbon habitat.Currently,the canopy heigh...The cao vit gibbon is a critically endangered species.Only approximately 110 individuals remain in degraded karst forest along the China-Vietnam border.Karst forest is unusual gibbon habitat.Currently,the canopy height of cao vit gibbon habitat is approximately 10 m.Research on the locomotor behavior of gibbons living in this particular forest type might provide important insight into locomotor stability and variability of gibbons.We used 5 min scan samples to record the locomotion mode,support use and canopy strata of gibbons in 3 groups for 2096 h between January 2008 and December 2009.Although cao vit gibbon habitat has a lower canopy in comparison to that of other forests inhabited by gibbons,cao vit gibbons displayed a similar overall locomotor pattern to other gibbon species(Symphalangus syndactylus,Hylobates lar and Hylobates agilis)in which brachiation dominate their locomotor behavior.Cao vit gibbons spent most of their time travelling on inclined branches(2-10 cm)in the middle stratum through the forest canopy.Adult females appear to more often employ safer modes of locomotion(bridging more often and brachiation less),while adult males choose riskier modes(leaping more and climbing less).As gibbons increased in body weight,as they grew from infant to adult,they tended to use larger supports.This research documented that locomotor behavior in Hylobatidae is strongly determined by anatomical characters,but cao vit gibbons also show the ability to use various supports,enabling them to survive in karst forest.展开更多
Black crested gibbons(Nomascus concolor)are 1 of only 3 gibbon species that have been observed in long-term polygynous groups,but their mating behavior and reproductive characters have never been reported.Based on pop...Black crested gibbons(Nomascus concolor)are 1 of only 3 gibbon species that have been observed in long-term polygynous groups,but their mating behavior and reproductive characters have never been reported.Based on population monitoring over 7 years and direct observation for 26 months of the study groups in Wuliang Mountain,central Yunnan,we describe for the first time the copulation behavior and breeding pattern of free-ranging western black crested gibbons.The gestation period of black crested gibbons is estimated to be between 6 and 7 months.The average breeding interval is 3.5 years,with infant independence at approximately 2.5 years.We observed 2 intra-group copulations and 5 extra-group copulations.Copulations were initiated when a female gave a‘solicitation’gesture.When a male made any mating attempt,the female might refuse it.These results demonstrate direct female mate choice.Both male and female gibbons dispersed from their natal groups and sometimes replaced paired adults in other groups.We observed no evidence of infanticide during inter-group conflicts or after replacement of adults.Together with extra-group copulations,these phenomena indicate a flexible social organization and complex mating system.We also observed a male-biased sex ratio among offspring.More genetic work is necessary to describe the effects of inter-group copulation and the genetic diversity of this population.展开更多
文摘The field research on five black crested gibbon groups, recently performed at Dazhaizi, Mr. Wuliang, Central Yunnan, China, showed that all groups in the local population consisted of one adult male, two adult females and 2 - 5 sub-adults, juveniles and itfants. The mean group size was 6.2 in August 2003 and 6.4 in August 2005. Two subadult males disappeared from their natal home range and three newborns were given birth in Group 3 （G3） and G4 during this study. The two adult females in G1, G2 and G3 gave births and/or carried babies but at different times. There was no aggressive or dominating behaviour observed between the two adult females. One floating female was first seen in G3＇s territory on April 15, 2005. The two resident females interrupted her duet with adult male and chased her. We did not observe adult male chased this floating female and she left G3＇s territory 10 days later. Sub-adult males often kept distance with the family, and they often sang solo bouts in their natal territory before they dispersed. The sub-adult males and females dispersed from natal territory and two adult resident females rejected the third one, which might were the reasons why the black gibbon groups were polygyny in Dazhaizi.
基金supported by the Yunnan Provincial Science and Technology Infrastructure Program(2011FB105)the National Natural Science Foundation of China(31070349).
文摘We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons(Nomascus concolor)using social network analysis.The spatial proximity changed seasonally and was affected by temperature and rainfall.Preferred proximity association was not distributed randomly among individuals.Kinship was one explanation for the social structure,as offspring preferred to maintain close proximity with their mothers.The proximity of infants to mothers decreased with age,and independent offspring had lower proximity to mothers than dependent ones.We found that the adult male had different proximity relationships with two different adult females.The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group.Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences.Temperature influenced group proximity association,with individual proximity increasing in the cold months and decreasing in the hot months.Group proximity decreased in months with higher anthropogenic disturbance.
基金supported by the Yunnan Provincial Science and Technology Infrastructure Program (2011FB105)the National Natural Science Foundation of China (31070349)
文摘We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons (Nomascus concolor) using social network analysis. The spatial proximity changed seasonally and was affected by temperature and rainfall. Preferred proximity association was not distributed randomly among individuals. Kinship was one explanation for the social structure, as offspring preferred to maintain close proximity with their mothers. The proximity of infants to mothers decreased with age, and independent offspring had lower proximity to mothers than dependent ones. We found that the adult male had different proximity relationships with two different adult females. The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group. Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences. Temperature influenced group proximity association, with individual proximity increasing in the cold months and decreasing in the hot months. Group proximity decreased in months with higher anthropogenic disturbance.
基金supported by the Wildlife Conservation Program of Yunnan Province,ChinaK.H. was supported by a JSPS Postdoctoral Fellowship for Overseas Researchers(P16092)
文摘Gibbons and siamangs （Hylobatidae） are well-known for their rapid chromosomal evolution,which has resulted in high speciation rate within the family.On the other hand,distinct karyotypes do not prevent speciation,allowing interbreeding between individuals in captivity,and the unwanted hybrids are ethically problematic as all gibbon species are endangered or critically endangered.Thus,accurate species identification is crucial for captive breeding,particularly in China where studbooks are unavailable.Identification based on external morphology is difficult,especially for hybrids,because species are usually similar in appearance.In this study,we employed G-banding karyotyping and fluorescence in situ hybridization （FISH） as well as a PCR-based approach to examine karyotypic characteristics and identify crested gibbons of the genus Nomascus from zoos and nature reserves in China.We characterized and identified five karyotypes from 21 individuals of Nomascus.Using karyotypes and mitochondrial and nuclear genes,we identified three purebred species and three hybrids,including one F2 hybrid between N.gabriellae and N.siki.Our results also supported that N.leucogenys and N.siki shared the same inversion on chromosome 7,which resolves arguments from previous studies.Our results demonstrated that both karyotyping and DNA-based approaches were suitable for identifying purebred species,though neither was ideal for hybrid identification.The advantages and disadvantages of both approaches are discussed.Our results further highlight the importance of animal ethics and welfare,which are critical for endangered species in captivity.
基金supported by the National Natural Science Foundation of China(#30900169)the International Foundation for Science+1 种基金the Conservation Leadership ProgrammeFauna and Flora International.
文摘The cao vit gibbon is a critically endangered species.Only approximately 110 individuals remain in degraded karst forest along the China-Vietnam border.Karst forest is unusual gibbon habitat.Currently,the canopy height of cao vit gibbon habitat is approximately 10 m.Research on the locomotor behavior of gibbons living in this particular forest type might provide important insight into locomotor stability and variability of gibbons.We used 5 min scan samples to record the locomotion mode,support use and canopy strata of gibbons in 3 groups for 2096 h between January 2008 and December 2009.Although cao vit gibbon habitat has a lower canopy in comparison to that of other forests inhabited by gibbons,cao vit gibbons displayed a similar overall locomotor pattern to other gibbon species(Symphalangus syndactylus,Hylobates lar and Hylobates agilis)in which brachiation dominate their locomotor behavior.Cao vit gibbons spent most of their time travelling on inclined branches(2-10 cm)in the middle stratum through the forest canopy.Adult females appear to more often employ safer modes of locomotion(bridging more often and brachiation less),while adult males choose riskier modes(leaping more and climbing less).As gibbons increased in body weight,as they grew from infant to adult,they tended to use larger supports.This research documented that locomotor behavior in Hylobatidae is strongly determined by anatomical characters,but cao vit gibbons also show the ability to use various supports,enabling them to survive in karst forest.
基金supported by the National Natural Science Foundation of China(31070349)Yunnan Provincial Science and Technology Infrastructure Program(2011FB105)the National Basic Research Program of China(2007CB411603).
文摘Black crested gibbons(Nomascus concolor)are 1 of only 3 gibbon species that have been observed in long-term polygynous groups,but their mating behavior and reproductive characters have never been reported.Based on population monitoring over 7 years and direct observation for 26 months of the study groups in Wuliang Mountain,central Yunnan,we describe for the first time the copulation behavior and breeding pattern of free-ranging western black crested gibbons.The gestation period of black crested gibbons is estimated to be between 6 and 7 months.The average breeding interval is 3.5 years,with infant independence at approximately 2.5 years.We observed 2 intra-group copulations and 5 extra-group copulations.Copulations were initiated when a female gave a‘solicitation’gesture.When a male made any mating attempt,the female might refuse it.These results demonstrate direct female mate choice.Both male and female gibbons dispersed from their natal groups and sometimes replaced paired adults in other groups.We observed no evidence of infanticide during inter-group conflicts or after replacement of adults.Together with extra-group copulations,these phenomena indicate a flexible social organization and complex mating system.We also observed a male-biased sex ratio among offspring.More genetic work is necessary to describe the effects of inter-group copulation and the genetic diversity of this population.
