Loss of cultural song diversity and the convergence of songs in a declining Hawaiian forest bird community

The effects of population decline on culturally transmitted behaviors in animals has rarely been described, but may have major implications to population viability. Learned vocal signals in birds are of critical importance to behaviors associated with reproduction, intrasexual interactions, and group cohesion, and the complexity of vocal signals such as song can serve as an honest signal of an individual’s quality as well as the viability of a population. In this study, we examined how rapid population declines recently experienced by Hawaiian honeycreepers on the island of Kaua‘i (USA) may have influenced the diversity, complexity, and similarity of learned honeycreeper songs. We analyzed the acoustic characteristics of songs recorded during 3 time periods over a 40-year time frame for three species of declining Kaua‘i honeycreepers. We detected a loss of song complexity and diversity over the 40-year time period that paralleled dramatic population declines. Concurrent with the loss of...动物种群衰退对其文化传承行为的影响鲜有报道，但其可能对种群生存力具有重大意义。鸟类的习得性鸣唱信号，对于繁殖、种内同性互动以及群体凝聚相关行为至关重要；而鸣唱等鸣唱信号的复杂性，可作为个体质量以及种群生存力的诚实信号。本研究针对美国考艾岛的夏威夷旋蜜雀近期遭遇的快速种群衰退，探究其如何影响旋蜜雀习得鸣唱的多样性、复杂性与相似性。研究分析了40年时间跨度内3个时段录制的3种处于衰退中的考艾岛旋蜜雀的鸣唱声学特征。结果发现，在40年的时间跨度内，鸣唱复杂性与多样性的下降与种群的急剧衰退同步发生。伴随这一下降的还有……