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 - roar Column B: frequency (Hz) Column C: underwater call level NOTE dB re 20 uPa Column D: in-air call level dB re 20 uPa Column E: in-air background noise level at this frequency dB re 20 uPa Column F: water - air difference dB Column G: location, 1-3, see paper for code Column H: seal in-air threshold dB re 20 uPa Column I: human in-air threshold dB re 20 uPa Column 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）与冰面雌性海豹之间的潜在通信行为开展了调查。 研究于南极洲戴维斯附近的三处采样点，完成了水下鸣声的空中与水下录制工作。 多数水下鸣声无法被空中录制捕捉，这一现象通常由风噪干扰所致。 可被空中录制到的鸣声，其空中幅度范围为：86Hz时32~74 dB re 20 μPa，至3.6kHz时4~38 dB re 20 μPa。 上述多数鸣声可被人类听觉感知。 在582次幅度测量（源自230段鸣声）中，仅26次的测量值处于5 dB至最高15 dB（高于港海豹（Phoca vitulina）空中检测阈值）的区间内。 冰面海豹仅能在声源临近且无风噪干扰的情况下，感知到极少数响度极高的水下鸣声。 水下鸣声在空中的低可检测性，大概率会阻碍冰下海豹与冰面海豹之间的有效通信。 如需获取更多相关信息，请参阅与ASAC项目2122（ASAC_2122）关联的其他元数据记录与数据集。 本数据集包含以下字段： 列A：标识代码说明：G=鸣咕声（grunt），T=颤鸣声（trill），CT=恒定频率颤鸣声（constant freq. trill），O=单音声（tone），C=突突声（chug），AW=上升哨声（ascending whistle），DW=下降哨声（descending whistle），L=低吼（growl），R=咆哮声（roar） 列B：频率（单位：Hz） 列C：水下鸣声级 注：以20微帕为参考的分贝值（dB re 20 μPa） 列D：空中鸣声级 以20微帕为参考的分贝值（dB re 20 μPa） 列E：该频率下的空中背景噪声级 以20微帕为参考的分贝值（dB re 20 μPa） 列F：水-气声级差（单位：dB） 列G：采样点位编号，取值1-3，具体编码规则详见相关学术论文 列H：海豹空中听阈值 以20微帕为参考的分贝值（dB re 20 μPa） 列I：人类空中听阈值 以20微帕为参考的分贝值（dB re 20 μPa） 列J：该频率下的海豹空中听阈值 以20微帕为参考的分贝值（dB re 20 μPa）