Female and male zebra finches (Taeniopygia guttata) preferences for normal and modified songs

The zebra finch is an established model species for song preference research in songbirds. In this study, a four-way choice operant paradigm (“carrousel” cage) was used to measure the spontaneous preference of adult birds of both sexes for song stimuli of four different categories: a conspecific song, a duration-stretched version and a vocoded version of the conspecific song, and a heterospecific great tit song. In an earlier operant song discrimination experiment both male and female zebra finches treated duration stretched and vocoded song versions as being different from a normal song. This study examines how the same modified songs are treated in a preference test. The results show that females exhibited a gradient of preferences: they preferred the normal and the duration-stretched song over the vocoded version of the conspecific song, but the vocoded conspecific songs were still preferred over the heterospecific great tit songs. Males preferred duration-stretched conspecific songs over heterospecific songs, but otherwise did not differentiate among the stimuli. In contrast to the discrimination study, the current study also shows a sex difference, with female song preference for normal and duration-stretched conspecific songs being stronger than male preferences. Our results demonstrate that the importance of particular song features as obtained in the context of an operant discrimination task and of a preference test can differ. This illustrates that combining different approaches and testing paradigms may help to better understand the significance of various acoustical parameters of birdsong in relation to its social and ecological functions and their relevance to both sexes.

斑胸草雀（zebra finch）是鸣禽鸣唱偏好研究领域公认的成熟模式物种。本研究采用四选一操作式实验范式（旋转笼，carrousel cage），用以测定成年雌雄斑胸草雀对四类鸣唱刺激的自发偏好：同种鸣唱、同种鸣唱的时长拉伸版本与声码化版本，以及异种大山雀（great tit）鸣唱。在早前的一项操作式鸣唱辨别实验中，雌雄斑胸草雀均将时长拉伸版与声码化版鸣唱识别为与正常鸣唱存在差异的刺激。本研究旨在探究相同的经修饰鸣唱在偏好测试中的响应模式。研究结果显示，雌性个体呈现出明确的偏好梯度：相较于同种鸣唱的声码化版本，它们更偏好正常鸣唱及时长拉伸版鸣唱；但相较于异种大山雀鸣唱，声码化的同种鸣唱仍更受雌性青睐。雄性个体则更偏好时长拉伸版同种鸣唱而非异种鸣唱，但在其余刺激间未表现出辨别偏好。与此前的辨别实验不同，本研究还揭示了性别差异：雌性对正常及时长拉伸版同种鸣唱的偏好强度显著高于雄性。本研究结果表明，在操作式辨别任务与偏好测试两类实验场景中，特定鸣唱特征的重要性可能存在差异。这说明，结合不同研究方法与实验范式，有助于更深入地理解鸣禽鸣唱的各项声学参数与其社会及生态功能间的关联，以及这些参数对雌雄个体的不同生物学意义。