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首页> 外文期刊>Wildfowl >Aspects of the breeding biology of Bewick's Swans Cygnus columbianus bewickii nesting in high densities in the Chaun River delta, Chukotka, east Russia
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Aspects of the breeding biology of Bewick's Swans Cygnus columbianus bewickii nesting in high densities in the Chaun River delta, Chukotka, east Russia

机译：俄罗斯东部楚科奇州Chaun河三角洲高密度筑巢的Bewick's天鹅Cygnus columbianus bewickii繁殖生物学方面

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摘要

The breeding biology of Bewick's Swans Cygnus columbianus bewickii nesting on Ayopechan Island in the Chaun River delta, Chukotka, northeast Russia was monitored from 2002-2013 inclusive, which coincided with a marked increase in the number of swans in the Eastern Population. A total of 535 nests were located during the study, and nest density, clutch size, egg dimensions, earliest hatch dates and nest success (i.e. whether at least one egg hatched) were recorded. Average nest density was 2.07 ± 0.25 nests/km2 (range = 0.98-3.33 nests/km2) and nest density appeared to increase over the study period, although the trend was not statistically significant. The minimum distance between two swan nests was 82 m, and average clutch size was 3.60 eggs (s.d.= 1.05; range = 1-7 eggs, n = 410 clutches). Nest success, recorded in 2009-2013, ranged from 32.2-72.2% and averaged 46.5%. Weather variables, such as the date on which temperatures rose above zero, the timing of snow melt, late May and early June temperatures, and a general (integrated) measure of spring weather conditions, were not significantly associated with nest density. Mean clutch size decreased during the study, through there being a decreasing proportion of large clutches of 5 and 6 eggs. Results are discussed in relation to a separate study of the breeding biology of Bewick's Swans in the Northwest European Population, which increased in numbers between the mid 1970s and the mid 1990s but is currently in decline.
机译：从2002年至2013年（含首尾），监测了位于俄罗斯东北部楚科奇地区Chaun河三角洲的Ayopechan岛上的Bewick天鹅天鹅座哥伦比亚bewickii的繁殖生物学，与此同时，东部种群中的天鹅数量也显着增加。在研究过程中总共发现了535个巢，并记录了巢密度，离合器大小，卵的大小，最早的孵化日期和成功的巢（即是否至少孵化了一个卵）。平均巢密度为2.07±0.25巢/平方千米（范围= 0.98-3.33巢/平方千米），并且在研究期间，巢密度似乎有所增加，尽管趋势没有统计学意义。两个天鹅巢之间的最小距离为82 m，平均离合大小为3.60个卵（标准差= 1.05;范围= 1-7个卵，n = 410个离合）。 Nest于2009-2013年取得的成功率介于32.2-72.2％之间，平均为46.5％。天气变量（例如温度升至零以上的日期，融雪的时间，5月下旬和6月初的温度以及春季天气状况的一般（综合）度量）与巢密度没有显着相关。在研究过程中，平均离合器尺寸减小了，这是因为5和6个鸡蛋的大型离合器的比例降低了。讨论的结果与西北欧洲人口中贝威克天鹅的繁殖生物学的单独研究有关，该研究在1970年代中期至1990年代中期期间数量增加，但目前正在下降。

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