Cultural traditions have been observed in a wide variety of animal species. It remains unclear, however, what is required for social learning to give rise to stable traditions: what level of precision and what learning strategies are required. We address these questions by fitting models of cultural evolution to learned bird song. We recorded 615 swamp sparrow (Melospiza georgiana) song repertoires, and compared syllable frequency distributions to the output of individual-based simulations. We find that syllables are learned with an estimated error rate of 1.85% and with a conformist bias in learning. This bias is consistent with a simple mechanism of overproduction and selective attrition. Finally, we estimate that syllable types could frequently persist for more than 500 years. Our results demonstrate conformist bias in natural animal behaviour and show that this, along with moderately precise learning, may support traditions whose stability rivals those of humans.

中文翻译：

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文化整合在鸟歌中产生了极其稳定的传统。

在许多动物物种中都观察到了文化传统。但是，尚不清楚社会学习如何形成稳定的传统所需：精确的水平和学习策略的要求。我们通过将文化进化模型与博学的鸟歌相匹配来解决这些问题。我们记录了615个沼泽麻雀（Melospiza georgiana）歌曲曲目，并将音节频率分布与基于个人的模拟输出进行了比较。我们发现，学习音节的估计错误率为1.85％，并且学习过程中存在顺应性偏倚。这种偏见与过度生产和选择性减员的简单机制是一致的。最后，我们估计音节类型可能会持续超过500年。