Through-ice communication by Weddell seals may not be practicable

Possible communication between territorial male Weddell seals (Leptonychotes weddellii) under the ice with females on the ice was investigated. In-air and underwater recordings of underwater calls were made at three locations near Davis, Antarctica. Most underwater calls were not detectable in air, often because of wind noise. In-air call amplitudes of detectable calls ranged from 32-74 dB re. 20 microPa at 86 Hz down to 4-38 dB re. 20 microPa at 3.6 kHz. Most of these would be audible to humans. Only 26 of 582 amplitude measurements (from 230 calls) ranged from 5 dB to a maximum of 15 dB above the minimum harbour-seal (Phoca vitulina) in-air detection threshold. Seals on the ice could likely hear a few very loud underwater calls but only if the caller was nearby and there were no wind noises. The low detectability of underwater calls in air likely precludes effective communication between underwater seals and those on the ice.See other metadata records and datasets associated with ASAC project 2122 (ASAC_2122) for further information.The fields in this dataset are:Column A: G = grunt, T = trill, CT = constant freq. trill, O = tone, C = chug, AW = ascending whistle, DW = descending whistle, L = growl, R - roarColumn B: frequency (Hz)Column C: underwater call level NOTE dB re 20 uPaColumn D: in-air call level dB re 20 uPaColumn E: in-air background noise level at this frequency dB re 20 uPaColumn F: water - air difference dBColumn G: location, 1-3, see paper for codeColumn H: seal in-air threshold dB re 20 uPaColumn I: human in-air threshold dB re 20 uPaColumn J: seal in-air threshold at this frequency dB re 20 uPa

本研究针对冰下领地雄性威德尔海豹（Leptonychotes weddellii）与冰面雌性海豹间的潜在通信行为展开探究。研究团队在南极洲戴维斯站附近的三个采样点位，开展了空中与水下的水下叫声录制工作。多数水下叫声无法通过空中渠道被侦测到，这一现象通常由环境风噪干扰所致。可被空中侦测到的叫声，其空中声压级范围为：86Hz时为32~74 dB re 20微帕，随频率升高至3.6kHz时降至4~38 dB re 20微帕。此类叫声多数可被人类听闻。在582次声压测量（源自230个叫声样本）中，仅有26次的测量值处于5 dB至最高15 dB（高于普通斑海豹（Phoca vitulina）的空中侦测阈值）的区间内。冰面海豹仅能在发声者距离较近且无环境风噪的情况下，才能听到极少数响度极高的水下叫声。水下叫声的空中可侦测性极低，这大概率会阻碍冰下海豹与冰面海豹之间的有效通信。
如需获取进一步相关信息，请参阅与ASAC项目2122（ASAC_2122）关联的其他元数据记录与数据集。本数据集各字段说明如下：
列A：编码含义为：G=grunt（低吼）、T=trill（颤鸣）、CT=constant freq. trill（恒定频率颤鸣）、O=tone（单音）、C=chug（突突声）、AW=ascending whistle（上升哨声）、DW=descending whistle（下降哨声）、L=growl（低吼/咆哮）、R=roar（轰鸣）
列B：频率（单位：Hz）
列C：水下叫声声级 注：dB re 20 μPa（参考声压为20微帕的分贝值）
列D：空中叫声声级 注：dB re 20 μPa
列E：该频率下的空中背景噪声级 单位：dB re 20 μPa
列F：水-空气声级差 单位：dB
列G：采样点位编号，取值为1-3，具体编码规则详见对应论文
列H：海豹空中侦测阈值 注：dB re 20 μPa
列I：人类空中侦测阈值 注：dB re 20 μPa
列J：该频率下的海豹空中侦测阈值 注：dB re 20 μPa