Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21025, USA.
Department of Psychology, Aichi University, Toyohashi, 4418522, Japan.
Learn Behav. 2021 Mar;49(1):150-158. doi: 10.3758/s13420-021-00465-6. Epub 2021 Mar 2.
Budgerigars (Melopsittacus undulatus) are small Australian parrots with a well-documented, learned vocal repertoire and a high degree of vocal production learning. These birds live in large, social flocks and they vocally interact with each other in a dynamic, reciprocal manner. We assume that budgerigars must process and integrate a wide variety of sensory stimuli when selecting appropriate vocal responses to conspecifics during vocal interactions, but the relative contributions of these different stimuli to that process are next to impossible to tease apart in a natural context. Here we show that budgerigars, under operant control, can learn to respond to specific stimuli with a specific vocal response. Budgerigars were trained to produce contact calls to a combination of auditory and visual cues. Birds learned to produce specific contact calls to stimuli that differed either in location (visual or auditory) or quality (visual). Interestingly, the birds could not learn to associate different vocal responses with different auditory stimuli coming from the same location. Surprisingly, this was so even when the auditory stimuli and the responses were the same (i.e., the bird's own contact call). These results show that even in a highly controlled operant context, acoustic cues alone were not sufficient to support vocal production learning in budgerigars. From a different perspective, these results highlight the significant role that social interaction likely plays in vocal production learning so elegantly shown by Irene Pepperberg's work in parrots.
虎皮鹦鹉（Melopsittacus undulatus）是一种小型澳大利亚鹦鹉，其具有记录详尽的习得性发声曲目和高度的发声学习能力。这些鸟类生活在大型的社会性群体中，它们以动态、互惠的方式彼此进行声音交流。我们假设虎皮鹦鹉在选择与同类进行声音互动时，必须处理和整合各种感官刺激，以产生适当的发声反应，但在自然环境中，很难理清这些不同刺激对这一过程的相对贡献。在这里，我们展示了虎皮鹦鹉可以在操作性条件作用下，学会对特定的声音刺激产生特定的发声反应。我们训练虎皮鹦鹉根据听觉和视觉线索组合发出联系叫声。鸟类学会了根据刺激的位置（视觉或听觉）或质量（视觉）来发出特定的联系叫声。有趣的是，鸟类无法学会将不同的发声反应与来自同一位置的不同听觉刺激联系起来。令人惊讶的是，即使听觉刺激和反应相同（即鸟类自己的联系叫声），也无法实现这一点。这些结果表明，即使在高度受控的操作性条件作用环境下，仅靠声学线索也不足以支持虎皮鹦鹉的发声学习。从另一个角度来看，这些结果强调了社会互动在发声学习中可能发挥的重要作用，这正是 Irene Pepperberg 在鹦鹉研究中所展示的。
