Wingfield John C, Hunt Kathleen E
Department of Zoology, Box 351800, University of Washington, Seattle, WA 98195, USA.
Comp Biochem Physiol B Biochem Mol Biol. 2002 May;132(1):275-86. doi: 10.1016/s1096-4959(01)00540-1.
Arctic breeding birds arrive on their nesting grounds in spring when weather conditions may still be extreme (low temperature, snow). The brief Arctic summer requires that they begin breeding as early as possible to take advantage of the ephemeral abundance of food to feed young. Failure to adjust to the local phenology results in drastically reduced reproductive success. Hormone-behavior adaptations may have evolved that maximize survival and reproductive success in the Arctic. It has been shown that the interrelationship of testosterone and territorial aggression, as birds arrive on the Arctic breeding grounds, varies according to species and locality. In some, territoriality is extremely brief following which birds become apparently refractory to the effects of testosterone. Others are territorial throughout the breeding season, but the dependence of these behaviors upon activation by testosterone is lost. Extensive data also indicate that Arctic birds modulate the adrenocortical response to acute stress. Secretion of corticosterone in response to a standardized capture stress protocol, used to mimic acute stress as a function of local environmental conditions, varies with the stage in the breeding cycle. Arctic breeding birds modulate the sensitivity of the adrenocortical response to acute stress at both the population and individual levels. These modulations are thought to be adaptations to allow the onset of territorial behavior and breeding in the face of potentially stressful conditions. Behavioral and physiological responses to corticosterone treatment are also diminished. A combination of these two hormone-behavior interrelationships can form important components of the proximate mechanisms by which birds, and other vertebrates, breed successfully in a severe and often capricious environment.
北极繁殖鸟类在春季抵达它们的筑巢地，此时天气条件可能仍然极端恶劣（低温、降雪）。短暂的北极夏季要求它们尽早开始繁殖，以便利用短暂丰富的食物来喂养幼鸟。未能适应当地物候会导致繁殖成功率大幅降低。可能已经进化出激素 - 行为适应性，以使北极地区的生存和繁殖成功率最大化。研究表明，随着鸟类抵达北极繁殖地，睾酮与领地攻击性之间的相互关系因物种和地点而异。在一些鸟类中，领地行为极为短暂，之后它们对睾酮的影响显然变得不敏感。另一些鸟类在整个繁殖季节都具有领地意识，但这些行为对睾酮激活的依赖性丧失。大量数据还表明，北极鸟类会调节肾上腺皮质对急性应激的反应。根据标准化的捕捉应激方案分泌皮质酮，该方案用于模拟作为当地环境条件函数的急性应激，其随繁殖周期的阶段而变化。北极繁殖鸟类在种群和个体水平上都会调节肾上腺皮质对急性应激反应的敏感性。这些调节被认为是一种适应性，以便在面对潜在压力条件时开始领地行为和繁殖。对皮质酮治疗的行为和生理反应也会减弱。这两种激素 - 行为相互关系的结合可以构成鸟类以及其他脊椎动物在严峻且多变的环境中成功繁殖的近端机制的重要组成部分。
