Background: The Red-crowned Crane(Grus japonensis) is an endangered bird species and while the wild population continues to decrease in China, the captive population has dramatically increased over the last two decade...Background: The Red-crowned Crane(Grus japonensis) is an endangered bird species and while the wild population continues to decrease in China, the captive population has dramatically increased over the last two decades. We hypothesized that some of the captive Red-crowned Cranes originated from the wild and that a growing captive population is eroding the wild population in China.Methods: We surveyed the size of the population and determined the average annual growth rate, reproductive success rate and mortality rate of captive Red-crowned Cranes in 2013 in China. We assessed this erosion effect through mathematical models, in which the size of the captive Red-crowned Crane population was determined from the annual growth rate, the reproductive success rate and the rate of mortality.Results: We found there were a total of 1520 captive Red-crowned Cranes in 2013 in China, with an average annual gro-wth rate of 7.46%, a reproductive success rate of 9.17% and a mortality rate of 3.6%. We found that approximately 1027 supplementary Red-crowned Cranes per year and a total of 244, over the 14 year period from 1999 to 2013, were needed to account for the growing captive population in China.Conclusion: We conclude that the 244 birds probably came from the wild by taking eggs and capturing juveniles or adults and hence accepted the hypothesis. Perhaps more surprisingly, our annual estimate of the number of supplementary Red-crowned Cranes in captive populations is very conservative, with the erosion effect substantially underestimated, because the total number of captive Red-crowned Cranes in 2013 was underestimated, with the annual reproductive success rate in zoos overestimated. The existence of an erosion effect provides a new perspective for the interpretation of why the Red-crowned Crane population in the wild continues to decrease. In our opinion, it is important to understand the consequences of this erosion effect on the management and conservation of this endangered bird species in China.展开更多
A study was aimed to overlook biological status including egg hatching, diet and diseases of common, Grus grus L. and demoiselle, Anthropoidedes virgo L. cranes in captive form in the southern districts of the Norther...A study was aimed to overlook biological status including egg hatching, diet and diseases of common, Grus grus L. and demoiselle, Anthropoidedes virgo L. cranes in captive form in the southern districts of the Northern Pakistan. Field survey, questionnaire and interview with communities were the major tools for the data collection. Total 165 and 85 camps were visited, respectively, in fall, 2008 and spring, 2009. These camps were established in Baran dam, Kurram, Kashu, Kethu and Dowa in Bannu; and Gambilla, Lunder and Chall rivers in Lakki. The numbers of 1,650 hunters have 6,600 demoiselle and 3,300 common captive cranes in Bannu and Lakki, respectively. From 920 breeding pairs, 900 eggs were obtained, from which only 640 were hatched. Among natural foods of the cranes, snails, grasshoppers and earthworms, the pebbles were the most favorite foods. The young ones of cranes were fed on maize bread, eggs of insects and other small animals like wasp＇s larvae and grasshoppers by hunters. They faced the problems of development of feathers, trapping in mud and parasitic attack during their development. The cranes suffered from many diseases; head tumor, influenza and stomach blockage were the most common in the adults and young ones. The hunters used traditional things, garlic, coriander and brown sugar with antibiotics for treatments of diseases. Migratory cranes were found to be declining viewed by hunters in southern districts of Northern Pakistan. Knowledge about egg hatching, foods and diseases of common and demoiselle captive cranes, might be assisted in their conservation.展开更多
基于2018年中国圈养灰冠鹤(Balaerica regulorum)谱系数据,应用种群管理软件SPARKS v 1.66和PMx v1.2对国内灰冠鹤圈养种群进行统计学和遗传学分析。谱系分析结果显示,截至2018年12月31日,中国圈养灰冠鹤共有332只,饲养于41家单位。种...基于2018年中国圈养灰冠鹤(Balaerica regulorum)谱系数据,应用种群管理软件SPARKS v 1.66和PMx v1.2对国内灰冠鹤圈养种群进行统计学和遗传学分析。谱系分析结果显示,截至2018年12月31日,中国圈养灰冠鹤共有332只,饲养于41家单位。种群建立者16只,贡献值和繁殖后代数不均衡。灰冠鹤种群基因多样性为85.97%,根据过去30年种群变化趋势预测,100年后种群数量变化较小,但基因多样性会减至78.80%。为增加圈养灰冠鹤种群数量,促进种群健康发展,建议完善个体标记;开展未知性别个体的性别鉴定;加强机构间合作繁殖,增加潜在建立者繁殖机会;改善圈养环境;杜绝杂交个体的出现。展开更多
基金supported by the Special Fund for Basic Scientific Research of the Central Public Welfare Research Institutes (2013)the National Natural Science Foundation of China (No.31300350)+2 种基金the Jiangsu Provincial Natural Science Foundation of China (No.2011079)the Baseline Surveys and Assessments of Nature Reserves in China (No.HBSY0915)the State Environmental Protection Public Welfare Scientific Research Project (No.201209028)
文摘Background: The Red-crowned Crane(Grus japonensis) is an endangered bird species and while the wild population continues to decrease in China, the captive population has dramatically increased over the last two decades. We hypothesized that some of the captive Red-crowned Cranes originated from the wild and that a growing captive population is eroding the wild population in China.Methods: We surveyed the size of the population and determined the average annual growth rate, reproductive success rate and mortality rate of captive Red-crowned Cranes in 2013 in China. We assessed this erosion effect through mathematical models, in which the size of the captive Red-crowned Crane population was determined from the annual growth rate, the reproductive success rate and the rate of mortality.Results: We found there were a total of 1520 captive Red-crowned Cranes in 2013 in China, with an average annual gro-wth rate of 7.46%, a reproductive success rate of 9.17% and a mortality rate of 3.6%. We found that approximately 1027 supplementary Red-crowned Cranes per year and a total of 244, over the 14 year period from 1999 to 2013, were needed to account for the growing captive population in China.Conclusion: We conclude that the 244 birds probably came from the wild by taking eggs and capturing juveniles or adults and hence accepted the hypothesis. Perhaps more surprisingly, our annual estimate of the number of supplementary Red-crowned Cranes in captive populations is very conservative, with the erosion effect substantially underestimated, because the total number of captive Red-crowned Cranes in 2013 was underestimated, with the annual reproductive success rate in zoos overestimated. The existence of an erosion effect provides a new perspective for the interpretation of why the Red-crowned Crane population in the wild continues to decrease. In our opinion, it is important to understand the consequences of this erosion effect on the management and conservation of this endangered bird species in China.
文摘A study was aimed to overlook biological status including egg hatching, diet and diseases of common, Grus grus L. and demoiselle, Anthropoidedes virgo L. cranes in captive form in the southern districts of the Northern Pakistan. Field survey, questionnaire and interview with communities were the major tools for the data collection. Total 165 and 85 camps were visited, respectively, in fall, 2008 and spring, 2009. These camps were established in Baran dam, Kurram, Kashu, Kethu and Dowa in Bannu; and Gambilla, Lunder and Chall rivers in Lakki. The numbers of 1,650 hunters have 6,600 demoiselle and 3,300 common captive cranes in Bannu and Lakki, respectively. From 920 breeding pairs, 900 eggs were obtained, from which only 640 were hatched. Among natural foods of the cranes, snails, grasshoppers and earthworms, the pebbles were the most favorite foods. The young ones of cranes were fed on maize bread, eggs of insects and other small animals like wasp＇s larvae and grasshoppers by hunters. They faced the problems of development of feathers, trapping in mud and parasitic attack during their development. The cranes suffered from many diseases; head tumor, influenza and stomach blockage were the most common in the adults and young ones. The hunters used traditional things, garlic, coriander and brown sugar with antibiotics for treatments of diseases. Migratory cranes were found to be declining viewed by hunters in southern districts of Northern Pakistan. Knowledge about egg hatching, foods and diseases of common and demoiselle captive cranes, might be assisted in their conservation.
文摘基于2018年中国圈养灰冠鹤(Balaerica regulorum)谱系数据,应用种群管理软件SPARKS v 1.66和PMx v1.2对国内灰冠鹤圈养种群进行统计学和遗传学分析。谱系分析结果显示,截至2018年12月31日,中国圈养灰冠鹤共有332只,饲养于41家单位。种群建立者16只,贡献值和繁殖后代数不均衡。灰冠鹤种群基因多样性为85.97%,根据过去30年种群变化趋势预测,100年后种群数量变化较小,但基因多样性会减至78.80%。为增加圈养灰冠鹤种群数量,促进种群健康发展,建议完善个体标记;开展未知性别个体的性别鉴定;加强机构间合作繁殖,增加潜在建立者繁殖机会;改善圈养环境;杜绝杂交个体的出现。
