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
Population estimates of black crested gibbons in Wuliang Nature Reserve,Jingdong,Yunnan,China,with two techniques,average group density total area and average home rang forest coverage,produced quite similar result...Population estimates of black crested gibbons in Wuliang Nature Reserve,Jingdong,Yunnan,China,with two techniques,average group density total area and average home rang forest coverage,produced quite similar results.The population was estimated around 115 groups in the Reserve.The paper also discussed the conservation problems of the Reserve.At present,the main threat to the gibbons is habitat fragmentation and population isolation.Thus,it is urgent to prohibit hunting and protect the habitat and forest corridors or habitat bridges.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
In order to obtain information on the genetic structure of Abies concolor and the genetic variation among 11 popula- tions introduced from America to China, allozyme analysis based on starch gel electrophoresis techn...In order to obtain information on the genetic structure of Abies concolor and the genetic variation among 11 popula- tions introduced from America to China, allozyme analysis based on starch gel electrophoresis technology was used. 24 loci of 10 allozyme systems were mensurated, and the genetic structure and genetic diversity of the 11 populations of A. concolor evaluated. The results show that the genetic variation among is significant, and the genetic variation within A. concolor populations is more important. In contrast with other conifers, the variation of A. concolor is above the average level of conifers, and higher than the same level of Abies. The percentage of polymorphic loci (P) was 62.5%, the number of alleles per locus (A) 2.08, the number of ef- fective alleles per locus (Ae) was 1.37, the expected heterozygosity (H) 0.204, and the Shannon information index (I) 0.351 7. There is a short genetic distance (D=0.061) and a low gene flow (Nm=0.839 4) among the 11 introduced populations of A. concolor with high genetic variation. The genetic differentiation coefficient (Gst) was 0.229 5, which is higher than that of the mean in Abies or Pinus.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.
文摘Population estimates of black crested gibbons in Wuliang Nature Reserve,Jingdong,Yunnan,China,with two techniques,average group density total area and average home rang forest coverage,produced quite similar results.The population was estimated around 115 groups in the Reserve.The paper also discussed the conservation problems of the Reserve.At present,the main threat to the gibbons is habitat fragmentation and population isolation.Thus,it is urgent to prohibit hunting and protect the habitat and forest corridors or habitat bridges.
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 National 948 Project of China (Grant No. 2000-04-27)
文摘In order to obtain information on the genetic structure of Abies concolor and the genetic variation among 11 popula- tions introduced from America to China, allozyme analysis based on starch gel electrophoresis technology was used. 24 loci of 10 allozyme systems were mensurated, and the genetic structure and genetic diversity of the 11 populations of A. concolor evaluated. The results show that the genetic variation among is significant, and the genetic variation within A. concolor populations is more important. In contrast with other conifers, the variation of A. concolor is above the average level of conifers, and higher than the same level of Abies. The percentage of polymorphic loci (P) was 62.5%, the number of alleles per locus (A) 2.08, the number of ef- fective alleles per locus (Ae) was 1.37, the expected heterozygosity (H) 0.204, and the Shannon information index (I) 0.351 7. There is a short genetic distance (D=0.061) and a low gene flow (Nm=0.839 4) among the 11 introduced populations of A. concolor with high genetic variation. The genetic differentiation coefficient (Gst) was 0.229 5, which is higher than that of the mean in Abies or Pinus.
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.
