Acoustic signalling is evolutionarily important, influencing sexual selection and serving as a premating isolation mechanism. There is a strong evolutionary basis for acoustic signalling to occur nocturnally across many terrestrial vertebrate groups including mammals, reptiles and amphibians. Within some of these groups, there is a general assumption that ‘most taxa are nocturnal’ in their acoustic signalling, and this is a particularly strongly held view for most frogs. Here we challenge this well‐accepted notion by quantifying diurnal calling behaviour in Australian frogs, leveraging a continental‐wide citizen science dataset. Of 196 species present in the citizen science dataset, 140 (71%) were recorded at least once during the day. Of the most commonly observed species (i.e. species with at least 150 calls recorded in the database), there were surprisingly high rates of diurnal calling: 14 species had >25% of their calls recorded during the day. We also found that the relative rate of diurnal calling in frogs showed a strong phylogenetic signal, suggesting that the plasticity in calling behaviour as it relates to time of the day is strongly evolutionarily conserved. Our results highlight a suite of ecological and evolutionary questions that are worthy of further investigation.

中文翻译：

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大陆性评估青蛙呼唤行为的昼夜性

声音信号在进化上很重要，会影响性选择并充当重要的隔离机制。声音信号在包括哺乳动物，爬行动物和两栖动物在内的许多陆地脊椎动物群体中夜间发生，具有强大的进化基础。在这些人群中，有一个普遍的假设是，在它们的声音信号中“大多数分类单元是夜行性的”，这对于大多数青蛙来说是一个特别强烈的观点。在这里，我们利用整个大陆范围内的公民科学数据集，通过量化澳大利亚青蛙的日间呼唤行为来挑战这一公认的概念。在公民科学数据集中存在的196种物种中，有140种（71％）在一天中至少记录了一次。在最常观察到的物种（即数据库中记录了至少150个调用的物种）中，白天的呼唤率高得令人惊讶：白天有14个物种的呼唤记录大于25％。我们还发现青蛙的日间呼唤相对速率显示出很强的系统发生信号，这表明与一天中的时间相关的呼唤行为的可塑性得到了强烈的保守。我们的结果突出了一系列生态和进化问题，值得进一步研究。