Repetition patterns in Weddell seal (Leptonychotes weddellii) underwater multiple element calls

Many vocalisations produced by Weddell seals (Leptonychotes weddellii) are made up of repeated individual distinct sounds (elements). Patterning of multiple element calls was examined during the breeding season at Casey and Davis, Antarctica. Element and interval durations were measured from 405 calls all greater than 3 elements in length. The duration of the calls (22 plus or minus 16.6s) did not seem to vary with an increasing number of elements (F4.404 = 1.83, p = 0.122) because element and interval durations decreased as the number of elements within a call increased. Underwater vocalisations showed seven distinct timing patterns of increasing, decreasing, or constant element and interval durations throughout the calls. One call type occurred with six rhythm patterns, although the majority exhibited only two rhythms. Some call types also displayed steady frequency changes as they progressed. Weddell seal multiple element calls are rhythmically repeated and thus the durations of the elements and intervals within a call occur in a regular manner. Rhythmical repetition used during vocal communication likely enhances the probability of a call being detected and has important implications for the extent to which the seals can successfully transmit information over long distances and during times of high level background noise.

See other metadata records and datasets associated with ASAC project 2122 (ASAC_2122) for further information.

The fields in this dataset are:

Tape/Site/File
Filename
Call Type
Total Number of Elements
Attribute
Frequency
Time
Casey
Davis

威德尔海豹（Weddell seals，学名*Leptonychotes weddellii*）发出的诸多发声信号，均由重复出现的独立独特声音单元（elements）构成。本研究于南极洲凯西站与戴维斯站的繁殖季期间，针对多单元叫声的模式特征展开了分析。研究共选取405段时长不少于3个声音单元的叫声，对其中声音单元与间隔的持续时长进行了测量。单段叫声的总时长（22.0±16.6秒）并未随声音单元数量的增加而发生显著变化（F_(4,404)=1.83，p=0.122），这是因为随着单段叫声内声音单元数量的增多，单个单元与单元间隔的持续时长会相应缩短。水下发声信号共呈现7种截然不同的时序模式，涵盖叫声全程中声音单元与间隔时长递增、递减或保持恒定三种变化趋势。存在一类叫声可涵盖6种节律模式，但绝大多数叫声仅表现出2种节律。部分叫声类型在发声过程中还会呈现出稳定的频率变化。威德尔海豹的多单元叫声具有节律性重复的特征，因此单段叫声内的声音单元与单元间隔的持续时长均遵循固定规律。发声交流中采用的节律性重复模式，或可提升叫声被侦测到的概率，这对于威德尔海豹在远距离场景及高背景噪音环境下成功传递信息的能力具有重要意义。

如需获取更多信息，请查阅与ASAC项目2122（ASAC_2122）相关的其他元数据记录与数据集。

本数据集包含以下字段：
磁带/站点/文件
文件名
叫声类型
声音单元总数
属性
频率
时间
凯西站
戴维斯站