Louisiana Waterthrush (Parkesia motacilla) is a familiar singer in the Western Hemisphere family Parulidae, yet apparent geographic variations in its song and potentially related causal mechanisms have not received detailed examination in previously published studies. Here, we analyzed song pattern variations of 651 Louisiana Waterthrush singers in audio spectrogram recordings obtained from our field work and publicly accessible bioacoustics archives. Visual and auditory assessment of the introductory note sequence of each song identified three distinct song types (A, B, and C) and 88.3% of the songs were assigned to one of these types. Linear Discriminant Analysis and Random Forest methods were used to verify the assignments and showed strong agreement (>90%) for Type A with slightly less agreement on Types B and C. User error rates (proportion of the Linear Discriminant Analysis classifications that were incorrect) were <10% for Types A and B, but 26% for Type C, while producer error rates (proportion of the song type for which the Linear Discriminant Analysis was incorrect) were >25% for Types A and C, but <5% for Type B. Our findings confirmed in a subset of 87 individuals that most between-individual variation was in the number of notes and note sequence duration while most within-individual variation resulted from the percent of downstrokes. The location of each singer was plotted on a map of the breeding range and results indicated the song types have large-scale discrete geographic distributions that co-occur in some regions but not range-wide. Evaluation of the distributions provided tentative support for a hypothesis that two of the song types may independently exhibit congruence with the geographic extent of Pleistocene glacial boundaries and the third song type may be distinguished by a lack of congruence, but further investigation is needed to elucidate whether the song variations represent subpopulations with three separate evolutionary histories.

中文翻译：

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路易斯安那州水th（Parkesia motacilla）的歌曲类型变异及其地理分布

路易斯安那州的Waterthrush（Parkesia motacilla）是西半球Parulidae家族中一位熟悉的歌手，但是其歌曲中明显的地理差异以及可能相关的因果机制尚未在先前发表的研究中得到详细检查。在这里，我们分析了651位路易斯安那州Waterthrush歌手的歌曲模式变化，这些音频模式来自我们的现场工作和可公开获取的生物声学档案，从而获得了音频频谱图记录。视觉和听觉评估每首歌的介绍音符序列，确定了三种不同的歌曲类型（A，B和C），其中88.3％的歌曲被分配为其中一种。线性判别分析和随机森林方法用于验证分配，并显示出与A型的一致性强（> 90％），而与B和C型的一致性稍差。用户错误率（线性判别分析分类不正确的比例）对于类型A和B小于10％，对于类型C则为26％，而制作人错误率（线性判别分析不正确的歌曲类型的比例） ）的A型和C型> 25％，而B型<5％。我们的发现在87个个体的子集中证实，个体间的差异最大的是音符的数量和音符序列的持续时间，而个体间的差异最大。是由于下降的百分比。每位歌手的位置都绘制在繁殖范围的地图上，结果表明，歌曲类型具有大规模的离散地理分布，这些分布在某些地区同时发生，但不在整个范围内。