A preliminary comparison of a songbird's song repertoire size and other song measures between an urban and a rural site

Characteristics of birdsong, especially minimum frequency, have been shown to vary for some species between urban and rural populations and along urban-rural gradients. However, few urban-rural comparisons of song complexity—and none that we know of based on the number of distinct song types in repertoires—have occurred. Given the potential ability of song repertoire size to indicate bird condition, we primarily sought to determine if number of distinct song types displayed by Song Sparrows (Melospiza melodia) varied between an urban and a rural site. We determined song repertoire size of 24 individuals; 12 were at an urban (‘human-dominated’) site and 12 were at a rural (‘agricultural’) site. Then, we compared song repertoire size, note rate, and peak frequency between these sites. Song repertoire size and note rate did not vary between our human-dominated and agricultural sites. Peak frequency was greater at the agricultural site. Our finding that peak frequency was higher at the agri...

已有研究证实，部分鸟类的鸣唱特征（尤其是最低频率（minimum frequency））会因城乡种群差异以及城乡梯度（urban-rural gradients）变化而产生差异。然而，针对鸣唱复杂度（song complexity）开展的城乡对比研究寥寥无几——据我们所知，目前尚无基于鸣唱曲目（song repertoire）内独特鸣唱类型（distinct song types）数量的相关研究。
鉴于鸣唱曲目规模可潜在指示鸟类健康状况，本研究首要目标是探究歌带鹀（Song Sparrow，*Melospiza melodia*）的独特鸣唱类型数量在城市与野外样地间是否存在差异。我们共分析了24只个体的鸣唱曲目规模：其中12只采自"人类主导"的城市样地，另外12只采自"农业型"的野外样地。随后，我们对比了两地个体的鸣唱曲目规模、鸣唱速率（note rate）以及峰值频率（peak frequency）。
研究结果显示，人类主导样地与农业样地的歌带鹀在鸣唱曲目规模与鸣唱速率上并无显著差异。农业样地个体的鸣唱峰值频率更高。本研究发现农业样地的鸣唱峰值频率更高……