Data from: Learning to cope: vocal adjustment to urban noise is correlated with prior experience in black-capped chickadees

Urban noise can interfere with avian communication through masking, but birds can reduce this interference by altering their vocalizations. Although several experimental studies indicate that birds can rapidly change their vocalizations in response to sudden increases in ambient noise, none have investigated whether this is a learned response that depends on previous exposure. Black-capped chickadees (Poecile atricapillus) change the frequency of their songs in response to both fluctuating traffic noise and experimental noise. We investigated whether these responses to fluctuating noise depend on familiarity with noise. We confirmed that males in noisy areas sang higher frequency songs than those in quiet areas, but found that only males in already-noisy territories shifted songs upwards in immediate response to experimental noise. Unexpectedly, males in more quiet territories shifted songs downwards in response to experimental noise. These results suggest that chickadees may require prior experience with fluctuating noise to adjust vocalizations in such a way as to minimize masking. Thus, learning to cope may be an important part of adjusting to acoustic life in the city.

城市噪声可通过掩蔽（masking）效应干扰鸟类的交流，但鸟类可通过调整自身鸣唱来降低此类干扰。尽管多项实验研究表明，鸟类可针对环境噪声的突然升高快速调整鸣唱，但尚无研究探讨这一反应是否属于依赖于先前噪声暴露的习得性反应。黑头山雀（Poecile atricapillus）会根据波动的交通噪声与实验性噪声调整其鸣唱频率。我们针对此类对波动噪声的反应是否依赖于对噪声的熟悉程度展开了研究。我们证实，栖息于嘈杂区域的雄性黑头山雀的鸣唱频率高于安静区域的个体，但仅在已有噪声领地的雄性个体，才会在遭遇实验性噪声时即时上调鸣唱频率。出乎意料的是，栖息于更安静领地的雄性个体，反而会在实验性噪声刺激下下调鸣唱频率。上述结果表明，黑头山雀或许需要先经历波动噪声的暴露，才能通过调整鸣唱的方式最大限度降低掩蔽效应带来的干扰。因此，学会应对噪声或许是适应城市声学环境的重要一环。