Life history data for longer-lived tropical songbirds reduce breeding activity as they buffer impacts of drought

Droughts are expected to increase in frequency and severity with climate change. Population impacts of such harsh environmental events are theorized to vary with life history strategies among species. However, existing demographic models generally do not consider behavioral plasticity that may modify the impact of harsh events. Here we show that tropical songbirds in the New and Old World reduced reproduction during drought, with greater reductions in species with higher average long-term survival. Large reductions in reproduction by longer-lived species were associated with higher survival during drought than pre-drought years in Malaysia, whereas shorter-lived species maintained reproduction and survival decreased. Behavioral strategies of longer-lived, but not shorter-lived, species mitigated the effect of increasing drought frequency on long-term population growth. Behavioral plasticity can buffer the impact of climate change on populations of some species, and differences in plasti...随着气候变化，干旱的发生频率与强度预计将呈上升趋势。此类极端环境事件对种群的影响，理论上会因物种的生活史策略而异。然而，现有的种群统计模型通常未考虑可能调节极端事件影响的行为可塑性（behavioral plasticity）。本研究表明，新世界与旧世界的热带鸣禽在干旱期间会降低繁殖投入，且平均长期存活率更高的物种，其繁殖投入的降幅更为显著。在马来西亚，寿命更长的物种大幅缩减繁殖投入，其干旱期间的存活率较干旱前有所提升；而寿命较短的物种则维持繁殖投入不变，存活率却出现下降。寿命更长的物种（而非寿命较短的物种）所采取的行为策略，能够缓解干旱频率上升对种群长期增长的负面影响。行为可塑性能够缓冲气候变化对部分物种种群的影响，且不同物种间的可塑性差异（原文未完整给出）。