Seasonality in basal metabolic rate and thermal conductance in a long-distance migrant shorebird, the knot (Calidris canutus)
Seasonality in basal metabolic rate and thermal conductance in a long-distance migrant shorebird, the knot (Calidris canutus)
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长距离迁徙滨鸟（Calidris canutus）基础代谢率和热导的季节性
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
S. Daan
中科院分区：
文献类型：
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作者：
T. Piersma;N. Cadée;S. Daan
Calidris canutus过着季节性很强的生活，在北极的高冻土带上单独繁殖，在温带到热带河口的非繁殖期群居。它们的繁殖活动和对长途飞行的生理准备反映在明显的羽毛和体重变化上，即使在长期圈养的岛屿亚种（在格陵兰岛北部和加拿大东北部繁殖，在西欧越冬）在室外鸟舍中研究也是如此。在4月至7月期间，与自由生活的鸟类往返于北极高繁殖地的飞行有关的三到四次增肥期，代表了一个高体重期，在5月下旬至7月初达到高峰，对10个圈养岛屿结鸟的样本进行了四年的研究。在三个岛屿结中，基础代谢率和热导率具有一致和同步的年变化。基础代谢率在夏季体重高峰时最高。在被检查的个体中，基础代谢率与体重的指数约为1.4，可能反映了代谢昂贵的肌肉和器官的普遍肥大。换毛对基础代谢率的任何潜在影响都被巨大的季节性质量相关变化所掩盖。在繁殖羽毛中，隔热系数（热导率的反比）比冬季羽毛低1.35倍。这与轮廓羽毛的干质量低1.17的因素是平行的。在这个亚种中，繁殖季节确实是体温调节成本最低的时期。在圈养结中，基础代谢率和热导率的季节性变化可能反映了一种预期程序，以适应一年中不同时间环境的可变需求。
Knots Calidris canutus live highly seasonal lives, breeding solitarily on high arctic tundra and spending the non-breeding season in large social flocks in temperate to tropical estuaries. Their reproductive activities and physiological preparations for long flights are reflected in pronounced plumage and body mass changes, even in long-term captives of the islandica subspecies (breeding in north Greenland and northeast Canada and wintering in western Europe) studied in outdoor aviaries. The three to four fattening episodes in April-July in connection with the flights to and from the high arctic breeding grounds by free-living birds, are represented by a single period of high body mass, peaking between late May and early July in a sample of ten captive islandica knots studied over four years. There are consistent and synchronized annual variations in basal metabolic rate and thermal conductance in three islandica knots. Basal metabolic rate was highest during the summer body mass peak. Within the examined individuals, basal metabolic rate scales on body mass with an exponent of about 1.4, probably reflecting a general hypertrophy of metabolically expensive muscles and organs. Any potential effect of moult on basal metabolic rate was obscured by the large seasonal mass-associated variations. In breeding plumage, insulation (the inverse of thermal conductance) was a factor of 1.35 lower than in winter plumage. This was paralleled by the dry mass of contour feathers being a factor of 1.17 lower. In this subspecies the breeding season is indeed the period during which the costs of thermoregulation are lowest. In captive knots seasonal changes in basal metabolic rate and thermal conductance likely reflect an anticipatory programme adaptive to the variable demands made by the environment at different times of the year.