We provide quantitative evidence suggesting social learning in sperm whales across socio-cultural boundaries, using acoustic data from the Pacific and Atlantic Oceans. Traditionally, sperm whale populations are categorized into clans based on their vocal repertoire: the rhythmically patterned click sequences (codas) that they use. Among these codas, identity codas function as symbolic markers for each clan, accounting for 35-60% of codas they produce. We introduce a computational method to model whale speech, which encodes rhythmic micro-variations within codas, capturing their vocal style. We find that vocal style-clans closely align with repertoire-clans. However, contrary to vocal repertoire, we show that sympatry increases vocal style similarity between clans for non-identity codas, i.e. most codas, suggesting social learning across cultural boundaries. More broadly, this subcoda structure model offers a framework for comparing communication systems in other species, with potential implications for deeper understanding of vocal and cultural transmission within animal societies.

翻译：我们利用来自太平洋和大西洋的声学数据，提供了量化证据，表明抹香鲸能够跨越社会文化边界进行社会学习。传统上，抹香鲸种群根据其发声库（即它们使用的有节奏的咔哒声序列，称为“代码”）被划分为不同氏族。在这些代码中，身份代码作为每个氏族的符号标记，占其产生代码的35-60%。我们引入了一种计算方法来模拟鲸类语言，该方法编码了代码内的节奏微变异，从而捕捉其发声风格。我们发现，发声风格氏族与曲库氏族高度一致。然而，与发声曲库相反的是，我们表明同域共存会增加不同氏族之间非身份代码（即大多数代码）的发声风格相似性，这暗示了文化边界间的社会学习。更广泛地，这种子代码结构模型为比较其他物种的通信系统提供了一个框架，并对更深入理解动物社会内的声音和文化传播具有潜在意义。