ABSTRACT Hermit Warblers (Setophaga occidentalis) sing a formulaic, type I song to attract mates, in contrast to a repertoire of more complex, type II songs to defend territories. A single, dominant type I song, or a low diversity of type I songs, often occur within a geographic area. We provide the first comprehensive description of Hermit Warbler type I song variants throughout California, USA. We recorded type I songs from 1,588 males across 101 study sites in the state from April through July 2009–2014. Using those locations and a pre-existing range map of the species, we created a maximum entropy-based breeding habitat suitability map and classified the songs into 35 variants using a typological rubric. We validated consistent classification of songs for 87.5% of the birds. We then modeled the effects of recent fire history at the local scale (10 yr, 315 km2), the amount of breeding habitat at the regional scale (8,000 km2), and the distance between territories to examine factors involved in song sameness at the local scale. We found that the probability of different birds singing the same form declined with the amount of local fire, regional habitat, and distance, and that these findings were robust to uncertainty in our song classification rubric. Using a longitudinal analysis including additional data from 10 study areas revisited in 2019, we showed that song structure within forms had drifted since our initial visits 5–10 yr earlier, and that the evenness (e.g., Simpson's measure) of song forms increased at locations that had been burned by wildfire between visits. Taken together, the results suggest that wildfires and the mass effects of dispersal of birds singing rival song forms disrupt the uniformity of type I songs locally. The results demonstrate how species traits, such as birdsong, can be used to disentangle the ecological processes that regulate observed patterns in biodiversity. Further investigation is recommended to determine whether song pattern dynamics reflect underlying genetic differences and habitat specializations among subpopulations. LAY SUMMARY The diversity of song dialects sung by Hermit Warblers in California forests is influenced by fire history. After exhaustive surveys of >1,500 birds, we mapped the distribution of 35 song dialects throughout the state. Our results suggest that differences among these songs were generated as an epiphenomenon of different subpopulations specializing on different forest types. Dispersal due to fire, and the mass effects of birds from surrounding forests, likely disrupts the uniformity of song dialects within locations, thereby promoting dynamic diversity over the longer term.

中文翻译：

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野火和扩散的大规模影响破坏了加利福尼亚隐士莺的 I 型歌曲的局部一致性

摘要 隐士莺 (Setophaga occidentalis) 会唱一首公式化的 I 型歌曲来吸引配偶，这与更复杂的 II 型歌曲的曲目形成对比，以保卫领土。单一的、占主导地位的 I 类歌曲，或 I 类歌曲的多样性较低，通常出现在一个地理区域内。我们首次全面介绍了美国加利福尼亚州的 Hermit Warbler I 型歌曲变体。从 2009 年 4 月到 2014 年 7 月，我们在该州 101 个研究地点录制了 1,588 名男性的 I 类歌曲。使用这些位置和物种的预先存在的范围图，我们创建了一个基于最大熵的繁殖栖息地适宜性图，并使用类型分类将歌曲分为 35 个变体。我们验证了 87.5% 鸟类的歌曲分类一致。然后，我们对局部尺度（10 年，315 平方公里）、区域尺度（8,000 平方公里）的繁殖栖息地数量以及领土之间的距离对近期火灾历史的影响进行了建模，以检查涉及当地歌曲同一性的因素。规模。我们发现，不同鸟类歌唱相同形式的概率随着当地火灾数量、区域栖息地和距离的增加而下降，并且这些发现对我们的歌曲分类标准中的不确定性是稳健的。使用纵向分析（包括 2019 年重新访问的 10 个研究领域的额外数据），我们发现自 5-10 年前首次访问以来，形式中的歌曲结构发生了变化，并且歌曲形式的均匀度（例如，辛普森的测量）在各个位置增加在两次访问之间被野火烧毁的。综合起来，结果表明，野火和鸟类散播的集体效应破坏了当地 I 类歌曲的一致性。结果表明，如何利用鸟鸣等物种特征来解开调节观察到的生物多样性模式的生态过程。建议进一步调查以确定歌曲模式动态是否反映了亚种群之间潜在的遗传差异和栖息地专业化。LAY 总结 加州森林中隐士林莺演唱的歌曲方言的多样性受到火灾历史的影响。在对超过 1,500 只鸟类进行详尽调查后，我们绘制了全州 35 种歌曲方言的分布图。我们的结果表明，这些歌曲之间的差异是作为专门针对不同森林类型的不同亚群的附带现象而产生的。火灾造成的传播，以及来自周围森林的鸟类的大规模影响，可能会破坏当地歌曲方言的统一性，从而促进长期的动态多样性。