de Kort Selvino R, Eldermire Erin R B, Cramer Emily R A, Vehrencamp Sandra L
Laboratory of Ornithology, Cornell University, Ithaca, NY, USA.
Behav Ecol. 2009 Jan;20(1):200-206. doi: 10.1093/beheco/arn135. Epub 2008 Oct 23.
Using the responses of territory owners to playback to infer the territorial function of acoustic signals is common practice. However, difficulties with interpreting the results of such experiments have obscured our understanding of territorial signalling. For instance, a stronger response to playback is often interpreted as more aggressive, but there is no consensus as to whether this should be in response to the least or most threatening simulated intruder. Rather than following a gradual increase or decrease, the relationship between signal intensity and response strength may instead describe a peaked curve. We manipulated banded wren (Thryophilus pleurostictus) songs to simulate low-, median-, and high-performance singers and used these songs as stimuli in playback experiments. Banded wrens were less likely to approach the high-performance stimulus compared with the low- and median-performance stimuli. However, the birds that did approach the high-performance stimulus sang more than those that approached the low-performance stimulus. In addition, birds were more likely to match the songs when exposed to the median- and high-performance stimuli compared with the low-performance stimuli, and song matching predicted approach behavior. These results are in accordance with theoretical models of aggressive encounters in which low-performance opponents are challenged without further assessment. Median- and high-performance opponents, however, may require further assessment, and the latter may be perceived as too intimidating for approach.
利用领地所有者对回放声音的反应来推断声学信号的领地功能是常见的做法。然而，解释此类实验结果存在困难，这模糊了我们对领地信号的理解。例如，对回放声音更强的反应通常被解释为更具攻击性，但对于这应该是对最不具威胁性还是最具威胁性的模拟入侵者的反应，尚无共识。信号强度与反应强度之间的关系可能不是呈逐渐增加或减少的趋势，而是可能呈现出一个峰值曲线。我们对斑胸鹪鹩（Thryophilus pleurostictus）的歌声进行处理，以模拟低水平、中等水平和高水平的歌唱者，并将这些歌声用作回放实验中的刺激物。与低水平和中等水平的刺激相比，斑胸鹪鹩接近高水平刺激的可能性较小。然而，确实接近高水平刺激的鸟类比接近低水平刺激的鸟类鸣叫更多。此外，与低水平刺激相比，鸟类在接触中等水平和高水平刺激时更有可能模仿歌声，并且歌声模仿预示着接近行为。这些结果与攻击性遭遇的理论模型一致，在该模型中，低水平对手会在没有进一步评估的情况下受到挑战。然而，中等水平和高水平的对手可能需要进一步评估，而后者可能被认为过于令人生畏而无法接近。
