Ontogeny of audible and ultrasonic calls is poorly studied in Gerbillinae rodents. In this study, analysis of calls, emitted by pup and adult fat-tailed gerbils Pachyuromys duprasi during 420-s isolation-and-handling procedures, allowed testing two hypotheses. Hypothesis1 predicted that audible squeaks and clicks follow the same ontogenetic pathway (towards higher-frequency and shorter calls) that has been previously documented for the ultrasonic calls of fat-tailed gerbil. Hypothesis2 predicted that the audible call types would alternate with the ultrasonic call types along ontogeny in this species. Hypothesis1 was tested with comparison of acoustic variables of audible calls (squeaks and clicks), emitted by 1-10-day old pups and by adults. Clicks of 8.3-8.7 kHz and high-frequency squeaks of 1.92-3.57 kHz were present in pups and adults, whereas mid-frequency squeaks of 0.31-0.67 kHz and low-frequency squeaks of 0.04-0.11 kHz were only present in pups. In agreement with Hypothesis1, pup high-frequency squeaks were longer, lower in fundamental frequency and higher in peak frequency. Against predictions, clicks did not differ acoustically between pups and adults. Hypothesis2 was tested with comparison of percentages of test trials containing the audible and/or ultrasonic call types of pups, repeatedly tested in 15 age classes along ontogeny from 1 to 40 days of age and in adults. The audible calls occurred in all age classes, whereas the ultrasonic calls emerged from day five of pup life and then prevailed over the audible squeaks in all age classes. We discuss that, in fat-tailed gerbil, ontogenetic pathways of acoustic variables of audible and ultrasonic calls (towards higher-frequency and shorter calls) are unusual for rodents although are typical for social and echolocation calls of bats. The is another parallelism of acoustic communication between bats and rodents aside from the recently discovered similarity between bat ultrasonic echolocation and echo-based navigation with bouts of ultrasonic calls in blind leaping rodents.

中文翻译：

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声音范围广的啮齿动物——肥尾沙鼠（Pachyuromys duprasi）的声音呼叫及其与超声波发声的个体发育关系

在 Gerbillinae 啮齿动物中，对听觉和超声波呼叫的个体发育研究很少。在这项研究中，对幼犬和成年肥尾沙鼠 Pachyuromys duprasi 在 420 秒的隔离和处理过程中发出的叫声进行了分析，允许测试两个假设。假设 1 预测，可听见的吱吱声和咔哒声遵循与先前记录的肥尾沙鼠超声波呼叫相同的个体遗传途径（朝向更高频率和更短的呼叫）。假设 2 预测，在该物种的个体发育过程中，可听见的呼叫类型将与超声波呼叫类型交替出现。假设 1 通过比较 1-10 天大的幼犬和成年人发出的可听叫声（吱吱声和咔嗒声）的声学变量进行了测试。幼崽和成虫出现 8.3-8.7 kHz 的咔嗒声和 1.92-3.57 kHz 的高频吱吱声，而 0.31-0.67 kHz 的中频吱吱声和 0.04-0.11 kHz 的低频吱吱声仅存在于幼崽中。与假设 1 一致，幼犬高频吱吱声更长，基频更低，峰值频率更高。与预测相反，幼崽和成年之间的咔嗒声在声学上没有差异。假设 2 是通过比较包含幼犬的听觉和/或超声波呼叫类型的测试试验的百分比进行测试的，这些测试试验在 15 个年龄组中从 1 到 40 日龄的个体发育和成人重复测试。可听见的叫声发生在所有年龄段，而超声波叫声从幼犬出生的第五天开始出现，然后在所有年龄级别的可听见的吱吱声中占优势。我们在肥尾沙鼠中讨论，可听和超声波的声学变量（朝向更高频率和更短的呼叫）的个体发生途径对于啮齿动物来说是不寻常的，尽管对于蝙蝠的社交和回声定位呼叫来说是典型的。除了最近发现的蝙蝠超声波回声定位和基于回声的导航之间的相似性之外，蝙蝠和啮齿动物之间的声学​​通信的另一个相似之处是盲跳啮齿动物的超声波呼叫。