Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States of America.
Department of Biology, University of Missouri-St. Louis, St. Louis, Missouri, United States of America.
PLoS One. 2020 Aug 17;15(8):e0233627. doi: 10.1371/journal.pone.0233627. eCollection 2020.
We studied avian development in 49 to 153 species of temperate and tropical New World passerine birds to determine how growth rates, and incubation and nestling periods, varied in relation to other life-history traits. We collected growth data and generated unbiased mass and tarsus growth rate estimates (mass n = 92 species, tarsus n = 49 species), and measured incubation period (n = 151) and nestling period (n = 153), which we analyzed with respect to region, egg mass, adult mass, clutch size, parental care type, nest type, daily nest predation rate (DMR), and nest height. We investigated covariation of life-history and natural-history attributes with the four development traits after controlling for phylogeny. Species in our lowland tropical sample grew 20% (incubation period), 25% (mass growth rate), and 26% (tarsus growth rate) more slowly than in our temperate sample. Nestling period did not vary with respect to latitude, which suggests that tropical songbirds fledge in a less well-developed state than temperate species. Suboscine species typically exhibited slower embryonic and post-embryonic growth than oscine passerines regardless of their breeding region. This pattern of slow development in tropical species could reflect phylogenetic effects based on unknown physiological attributes. Time-dependent nest mortality was unrelated to nestling mass growth rate, tarsus growth rate, and incubation period, but was significantly associated with nestling period. This suggests that nest predation, the predominant cause of nest loss in songbirds, does not exert strong selection on physiologically constrained traits, such as embryonic and post-embryonic growth, among our samples of temperate and lowland tropical songbird species. Nestling period, which is evolutionarily more labile than growth rate, was significantly shorter in birds exposed to higher rates of nest loss and nesting at lower heights, among other traits. Differences in life-history variation across latitudes provide insight into how unique ecological characteristics of each region influence physiological processes of passerines, and thus, how they can shape the evolution of life histories. While development traits clearly vary with respect to latitude, trait distributions overlap broadly. Life-history and natural history associations differ for each development trait, which suggests that unique selective pressures or constraints influence the evolution of each trait.
我们研究了 49 到 153 种温带和热带新世界雀形目鸟类的鸟类发育情况，以确定增长率以及孵化和育雏期如何与其他生活史特征相关变化。我们收集了生长数据，并生成了无偏质量和跗跖生长率估计值（质量 n = 92 种，跗跖 n = 49 种），并测量了孵化期（n = 151）和育雏期（n = 153），我们分析了区域、卵质量、成鸟质量、巢卵数、亲代照顾类型、巢类型、每日巢捕食率（DMR）和巢高与这四个发育特征的关系。在控制了系统发育后，我们研究了生活史和自然史属性与四个发育特征的协变关系。与我们的温带样本相比，我们的低地热带样本中的物种孵化期（20%）、质量生长率（25%）和跗跖生长率（26%）增长更慢。纬度与育雏期无关，这表明热带鸣禽在发育状态上不如温带物种完善。亚鸣禽物种的胚胎和胚胎后生长速度通常比鸣禽慢，无论它们的繁殖区域如何。热带物种发育缓慢的这种模式可能反映了基于未知生理特征的系统发育效应。与雏鸟质量生长率、跗跖生长率和孵化期无关，但与育雏期显著相关的是时间依赖的巢死亡率。这表明，在我们的温带和低地热带鸣禽物种样本中，巢捕食是导致鸟巢损失的主要原因，它对生理上受限制的特征（如胚胎和胚胎后生长）没有产生强烈的选择。在其他特征中，与巢死亡率较高和筑巢高度较低的鸟类相比，育雏期较短，而育雏期在进化上比生长率更不稳定。纬度间的生活史变化差异提供了对每个地区独特生态特征如何影响鸣禽生理过程的深入了解，以及它们如何影响生活史的进化。虽然发育特征显然与纬度有关，但特征分布广泛重叠。每个发育特征的生活史和自然史关联都不同，这表明独特的选择压力或限制影响了每个特征的进化。
