In 2008 and 2009,we made continuous and repeated breeding surveys of the Scaly-sided Merganser(Mergus squamatus)in the Changbai Mountain range(China side),using a combination of rubber-boat drifting and walking.Each s...In 2008 and 2009,we made continuous and repeated breeding surveys of the Scaly-sided Merganser(Mergus squamatus)in the Changbai Mountain range(China side),using a combination of rubber-boat drifting and walking.Each survey consisted of a census of breeding pairs in the spring and broods in the summer.A total of 1553 km in length of 17 river stretches were surveyed in four different river systems of the Yalujiang,Songhuajiang,Tumenjiang and Mudanjiang rivers.A total of 1354 individuals of the Scaly-sided Merganser were recorded during the both surveys.The breeding density for all the stretches surveyed over both years averaged 0.26 ± 0.30 pairs per km;the population density in the spring averaged 0.75 ± 0.88 individuals per km.According to our survey results,we estimated that the breeding population in the Changbai Mountain range was about 170 breeding pairs of the Scaly-sided Merganser.Three major breeding sites of this bird were found in the Changbai Mountain range in these surveys.展开更多
Background: The foraging and diving behavior of waterfowl are affected by a number of important factors. Hence, learning more about these major factors is of great concern in order to protect endangered species. In th...Background: The foraging and diving behavior of waterfowl are affected by a number of important factors. Hence, learning more about these major factors is of great concern in order to protect endangered species. In this study, we verified the effect of sex, temperature, time and flock size on the diving behavior of the Scaly-sided Merganser(Mergus squamatus).Methods: The study was conducted by means of focal animal sampling in the Wuyuan section of the Poyang Lake watershed in Jiangxi Province, China from December 2015 to March 2016. We used one-way ANOVA and LSD tests to investigate the differences among these factors. Pearson correlations were used to test the relation between pause duration and the previous or subsequent dive duration. The relations between these factors and dive/pause duration are illustrated using Spearman correlations.Results: Mean dive duration and mean time on the pause of males were significantly higher than those of females. With an increase in temperature, dive duration significantly increased. Along with the passage of time of year and daytime, dive duration significantly increased, while dive duration decreased significantly with the increase in flock size.Conclusions: Sex, temperature, time and flock size have an effect on the diving behavior of the wintering Scalysided Merganser. The difference of diving behavior between males and females is related to differences in body mass. The difference of diving behavior among various temperatures and time periods may be related to a low minimum rate of oxygen consumption, while the difference among various flock sizes may be caused by rising intraspecific competition.展开更多
本文报道了长白山中华秋沙鸭(Mergus squamatus)的窝雏合并行为,即亲鸟将不相关的其他雏鸟并入自己的窝雏之中进行混群抚育的现象。2017—2020年的4个繁殖季节,中华秋沙鸭在长白山漫江河道的平均营巢密度为(0.65±0.17)巢·km^(...本文报道了长白山中华秋沙鸭(Mergus squamatus)的窝雏合并行为,即亲鸟将不相关的其他雏鸟并入自己的窝雏之中进行混群抚育的现象。2017—2020年的4个繁殖季节,中华秋沙鸭在长白山漫江河道的平均营巢密度为(0.65±0.17)巢·km^(-1)(n=4),出雏后的家庭群密度为(0.39±0.05)群·km^(-1)(n=4)。4年中共统计到37个家庭群,平均窝雏数为(8.5±2.8)(n=37)。发生窝雏合并的家庭群比例平均为26.5%±6.8%(n=4),在不同年份间差异不显著。发生窝雏合并的家庭群与未发生窝雏合并的家庭群的窝雏数无显著差异(8.3±2.3 vs 8.5±3.0),但合并群雏鸭的数量(18.3±8.3)显著大于家庭群的窝雏数。大部分(83.3%)窝雏合并发生在雏鸭30日龄以前,发生的地点在觅食场所或休息场所,其原因可能是亲鸟之间的争斗抢占或雏鸭的意外走失和混群。中华秋沙鸭窝雏合并现象的发生,可能与长白山地区营巢密度较高、亲鸟竞争育雏领域有关,也可能与该物种单亲抚育后代、缺少对窝雏的有效保护相关。建议今后使用彩环标记和分子生物学手段,进一步探明这一濒危物种窝雏合并现象的内在机制,评估亲鸟因窝雏合并导致的适合度变化。展开更多
基金sponsored by the Rufford Small Grant of the Rufford Foundation
文摘In 2008 and 2009,we made continuous and repeated breeding surveys of the Scaly-sided Merganser(Mergus squamatus)in the Changbai Mountain range(China side),using a combination of rubber-boat drifting and walking.Each survey consisted of a census of breeding pairs in the spring and broods in the summer.A total of 1553 km in length of 17 river stretches were surveyed in four different river systems of the Yalujiang,Songhuajiang,Tumenjiang and Mudanjiang rivers.A total of 1354 individuals of the Scaly-sided Merganser were recorded during the both surveys.The breeding density for all the stretches surveyed over both years averaged 0.26 ± 0.30 pairs per km;the population density in the spring averaged 0.75 ± 0.88 individuals per km.According to our survey results,we estimated that the breeding population in the Changbai Mountain range was about 170 breeding pairs of the Scaly-sided Merganser.Three major breeding sites of this bird were found in the Changbai Mountain range in these surveys.
基金supported by the National Natural Science Foundation of China(Grant No.31560597)
文摘Background: The foraging and diving behavior of waterfowl are affected by a number of important factors. Hence, learning more about these major factors is of great concern in order to protect endangered species. In this study, we verified the effect of sex, temperature, time and flock size on the diving behavior of the Scaly-sided Merganser(Mergus squamatus).Methods: The study was conducted by means of focal animal sampling in the Wuyuan section of the Poyang Lake watershed in Jiangxi Province, China from December 2015 to March 2016. We used one-way ANOVA and LSD tests to investigate the differences among these factors. Pearson correlations were used to test the relation between pause duration and the previous or subsequent dive duration. The relations between these factors and dive/pause duration are illustrated using Spearman correlations.Results: Mean dive duration and mean time on the pause of males were significantly higher than those of females. With an increase in temperature, dive duration significantly increased. Along with the passage of time of year and daytime, dive duration significantly increased, while dive duration decreased significantly with the increase in flock size.Conclusions: Sex, temperature, time and flock size have an effect on the diving behavior of the wintering Scalysided Merganser. The difference of diving behavior between males and females is related to differences in body mass. The difference of diving behavior among various temperatures and time periods may be related to a low minimum rate of oxygen consumption, while the difference among various flock sizes may be caused by rising intraspecific competition.
文摘本文报道了长白山中华秋沙鸭(Mergus squamatus)的窝雏合并行为,即亲鸟将不相关的其他雏鸟并入自己的窝雏之中进行混群抚育的现象。2017—2020年的4个繁殖季节,中华秋沙鸭在长白山漫江河道的平均营巢密度为(0.65±0.17)巢·km^(-1)(n=4),出雏后的家庭群密度为(0.39±0.05)群·km^(-1)(n=4)。4年中共统计到37个家庭群,平均窝雏数为(8.5±2.8)(n=37)。发生窝雏合并的家庭群比例平均为26.5%±6.8%(n=4),在不同年份间差异不显著。发生窝雏合并的家庭群与未发生窝雏合并的家庭群的窝雏数无显著差异(8.3±2.3 vs 8.5±3.0),但合并群雏鸭的数量(18.3±8.3)显著大于家庭群的窝雏数。大部分(83.3%)窝雏合并发生在雏鸭30日龄以前,发生的地点在觅食场所或休息场所,其原因可能是亲鸟之间的争斗抢占或雏鸭的意外走失和混群。中华秋沙鸭窝雏合并现象的发生,可能与长白山地区营巢密度较高、亲鸟竞争育雏领域有关,也可能与该物种单亲抚育后代、缺少对窝雏的有效保护相关。建议今后使用彩环标记和分子生物学手段,进一步探明这一濒危物种窝雏合并现象的内在机制,评估亲鸟因窝雏合并导致的适合度变化。
