Experimental amelioration of harsh weather speeds growth and development in a tropical montane songbird

Organisms living at high elevations generally grow and develop slower than those at lower elevations. Slow montane ontogeny is thought to be an evolved adaptation to harsh environments that improve juvenile quality via physiological tradeoffs. However, slower montane ontogeny may also reflect proximate influences of harsh weather on parental care and offspring development. We experimentally heated and protected nests from rain to ameliorate harsh montane weather conditions for Mountain Blackeyes (Chlorocharis emiliae), a montane songbird living at ca. 3200 m asl in Malaysian Borneo. This experiment was designed to test if cold and wet montane conditions contribute to parental care and post-natal growth and development rates at high elevations. We found that parents increased provisioning and reduced time spent warming offspring, which grew faster and departed the nest earlier compared to unmanipulated nests. Earlier departure reduces time-dependent predation risk, benefitting parents an...

栖息于高海拔区域的生物，其生长发育速率普遍低于低海拔的同类个体。山地物种迟缓的个体发育过程，以往被认为是适应严酷环境的演化适应性策略——通过生理权衡提升幼体质量。然而，山地个体发育迟缓也可能源于恶劣天气对亲代抚育行为与幼体发育的直接影响。本研究以栖息于马来西亚婆罗洲海拔约3200米处的山地鸣禽山黑眼（Mountain Blackeyes, Chlorocharis emiliae）为对象，通过实验为其巢箱加温并遮挡雨水，以缓解山地恶劣天气的胁迫。本实验旨在验证高海拔地区阴冷潮湿的环境是否会影响亲代抚育与幼鸟出壳后的生长发育速率。结果显示，与未进行人工干预的对照巢箱相比，亲鸟会增加食物投喂频次并减少为幼鸟保温的时间，幼鸟生长速率更快、离巢时间更早。更早离巢可降低依赖于时长的捕食风险，使亲代受益……