ABSTRACT Territorial defence and maintaining contact are two hypotheses of duet functions. Nevertheless, the acoustic characteristics of duets in these contexts have been poorly quantified. This work aimed to compare the spectrotemporal characteristics and synchronisation in White-eared Ground-sparrow duets produced in aggressive context (i.e. territorial defence) and non-aggressive context (i.e. pair-contact). We expected to observe differences when compare duets of the same pair in each context. For this, we recorded 35 pairs in each context: territorial defence and pair-contact. We measured duration, minimum, highest, and maximum amplitude frequency. Synchronisation was measured comparing time and frequency bandwidth variation in three sections of duets produced in both contexts. In territory defence contexts, duets showed lower minimum frequencies and were produced with lower frequency synchronisation between first and middle section bandwidth; but with higher frequency synchronisation between middle and final section bandwidth. This suggests that this ground-sparrow encode context-depend information changing the frequency characteristics of duets. For example, to decrease the minimum frequency on the duets produced in territorial defence context could be understood as a most aggressive signal to the intruder, because in several species low-frequency sounds are associated with higher probability to attack the intruders or with larger and dominant individuals.

中文翻译：

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高度重叠的二重唱的频率和同步特征根据上下文变化

摘要领土防御和保持联系是二重奏功能的两个假设。然而，在这些情况下二重奏的声学特征很难量化。这项工作旨在比较在侵略性环境（即领土防御）和非侵略性环境（即成对接触）中产生的白耳地麻雀二重唱的光谱时间特征和同步。我们希望在每个上下文中比较同一对的二重唱时会观察到差异。为此，我们在每种情况下记录了 35 对：领土防御和对接触。我们测量了持续时间、最小、最大和最大振幅频率。通过比较在两种情况下产生的三段二重奏中的时间和频率带宽变化来测量同步。在领土防御方面，二重奏显示出较低的最低频率，并且在第一和中间部分带宽之间以较低频率同步产生；但在中间和最后部分带宽之间具有更高的频率同步。这表明这种地麻雀编码了上下文相关信息，改变了二重奏的频率特性。例如，降低在领土防御环境中产生的二重奏的最小频率可以被理解为对入侵者最具侵略性的信号，因为在几个物种中，低频声音与攻击入侵者的可能性更高或更大和占主导地位有关个人。这表明这种地麻雀编码了上下文相关信息，改变了二重奏的频率特性。例如，降低在领土防御环境中产生的二重奏的最小频率可以被理解为对入侵者最具侵略性的信号，因为在几个物种中，低频声音与攻击入侵者的可能性更高或更大且占主导地位的声音有关个人。这表明这种地麻雀编码了上下文相关信息，改变了二重奏的频率特性。例如，降低在领土防御环境中产生的二重奏的最小频率可以被理解为对入侵者最具侵略性的信号，因为在几个物种中，低频声音与攻击入侵者的可能性更高或更大和占主导地位有关个人。