Abstract

Using the patterns of fault bars in their primaries, we studied the mode of primary replacement in non-molting Lesser Sandhill Cranes (Antigone c. canadensis) salvaged from hunters in southwestern Saskatchewan. About 80% of their primaries are used for 2 yr and 20% for 3 yr. Primaries are replaced during the breeding season and are lost in synchronous blocks representing about half the primaries, suggesting that most adults probably can fly weakly during flight feather replacement. Cranes are large, aggressive birds, and this interesting, and undescribed mode of flight feather replacement seems adapted to the ability of adult cranes to defend their precocial chicks from predators. Strikingly, juvenile Sandhill Cranes showed no fault marks in their primaries, suggesting that their parents’ ability to protect them shields them from the fright of predator attacks, which, in most birds, causes fault bars to be more prevalent and strongly expressed in juveniles than adults. Adults show interesting variation in the number of primaries replaced annually, which seems likely related to whether or not they are caring for chicks. Further, single primaries may or may not be replaced preferentially, suggesting sensitivity to feather function. Evaluating these observations must await field studies of molting adults.

中文翻译：

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迁徙小沙丘鹤对生活中的相邻初生块同步更换的生活史意义

摘要

我们使用断裂条形图样中的原始图样，研究了非定型小沙丘鹤（Antigone c。canadensis）中的主要替换模式。）从萨斯喀彻温省西南部的猎人那里救出。他们大约80％的小学使用2年，20％使用3年。在繁殖季节替换原色，并在约占原色一半的同步块中丢失，这表明大多数成年鸟在替换羽毛时可能会虚弱地飞行。鹤是大型的，有攻击性的鸟，这种有趣的，未描述的飞行羽毛替换方式似乎适应了成年鹤保护其早熟雏免受掠食者侵害的能力。令人吃惊的是，幼年的沙丘鹤在其原发中未显示任何断层痕迹，这表明其父母保护它们的能力使它们免受捕食者袭击的恐惧，这在大多数鸟类中，导致断条在幼年中比在幼年中更为普遍和强烈地表达。大人。成年动物每年更换的初选细菌数量显示出有趣的变化，这似乎与他们是否照顾小鸡有关。此外，单个原色可能会或可能不会被优先替换，表明对羽毛功能敏感。评价这些观察结果必须等待对蜕皮成虫的野外研究。