Testosterone and year-round territoriality in tropical and non-tropical songbirds
Testosterone and year-round territoriality in tropical and non-tropical songbirds
复制标题
热带和非热带鸣禽的睾丸激素和全年领地性
DOI：
10.1111/j.1600-048x.2011.05464.x
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发表时间：
2011
影响因子：
1.7
通讯作者：
Mėta M. Landys
中科院分区：
文献类型：
--
作者：
W. Goymann;Mėta M. Landys
过去的研究表明，热带和北方纬度雄性鸟类之间的睾酮浓度存在根本差异，传统的做法是热带雄性鸟类的睾酮水平要低得多。然而，最近的比较研究表明，繁殖季节短而同步的热带雄性（即典型的北方物种的繁殖季节）表达的睾酮水平最高，与北方纬度的鸟类相似。在这里，我们匡威问：表达热带典型的定义性生活史特征（即全年领土性）的北方纬度鸣禽是否具有与热带鸣禽相似的年度睾酮分布？对于几个全年的领土物种的数据可用，我们发现，季节性睾酮配置文件和季节性最大值血浆睾酮的热带和非热带物种之间的男性相似。例如，两组的男性在女性生育期间表达季节性最大值，此时的睾酮水平相似。相比之下，这项研究和其他研究表明，具有季节性领土的物种通常在繁殖周期的早期表达最大的睾酮水平，当领土首次建立时。两者合计，我们认为，特定的生活史性状可能发挥更重要的作用，在确定热带和非热带鸟类的睾酮配置文件比繁殖纬度，并鼓励进一步的研究，使更正式的比较。
Past studies have suggested a fundamental difference in testosterone concentrations between tropical and northern latitude male birds, with the convention being that males in the tropics express much lower levels of testosterone. However, recent comparative studies have shown that tropical males with a short and synchronous breeding season (i.e. a breeding season typical of northern species) express maximum testosterone levels similar to those of northern latitude birds. Here, we ask the converse: do northern latitude songbirds that express a defining life-history characteristic typical of the tropics, i.e. year-round territoriality, have an annual testosterone profile similar to that of tropical songbirds? For the few year-round territorial species for which data are available, we found that seasonal testosterone profiles and seasonal maxima in plasma testosterone were similar between males of tropical and non-tropical species. For example, males of both groups expressed seasonal maxima during the period when females were fertile, and testosterone levels at this time were similar. In contrast, this and other studies show that species with seasonal territories typically express maximum testosterone levels earlier in the breeding cycle, when territories are first being established. Taken together, we suggest that specific life-history traits may play a more important role in determining testosterone profiles of tropical and non-tropical birds than breeding latitude and encourage further studies to allow for more formal comparisons.