Variation of in-air female Weddell seal contact calls

From the abstract of the attached paper:

Vocal recognition may function as a critical factor in maintaining the phocid mother-pup bond during lactation. For vocal recognition to function, the caller must produce individually distinct calls that are recognised by their intended recipient. Mother-pup vocal recognition has been studied extensively in colonial otariids and appears to be characteristic of this family. Although less numerous, empirical studies of phocid species have revealed a range of recognition abilities. This study investigated whether Weddell seal (Leptonychotes weddellii) females produce individually distinct 'pup contact' calls that function during natural pair reunions. Fifteen calls from each of nine females recorded in the Vestfold Hills, Antarctica were analysed. One temporal, nine fundamental frequency and five spectral characteristics were measured. Results of the cross-validated Discriminant Function Analysis revealed that mothers produce individually distinct calls with 56% of calls assigned to the correct individual. The probability of achieving this level of discrimination on novel data by chance alone is highly improbable. Analysis of eight mother-pup reunions recorded near McMurdo Sound, Antarctica further demonstrated that these 'pup contact' calls function during natural pair reunions. Behavioural analysis also revealed that pups were chiefly responsible for establishing and maintaining close contact throughout the reunion process. Our study therefore demonstrates that Weddell seal females produce calls with sufficient stereotypy to allow pups to identify them during pair reunions, providing evidence of a functioning mother-pup vocal recognition system.

Column A - Row 1: Gives the tag number of the female.
- Rows 3-33: The list of acoustic measurements recorded from the spectrograms.
- Rows 3-5: Temporal measurements recorded in milliseconds.
- Rows 7-12: Frequency measurements recorded from the fundamental frequency. Rows 9-11 were measured at the 1/4, 2/4 and 3/4 temporal positions along the fundamental frequency respectively.
- Rows 13-17: Give the number of the frequency band with the most energy at the temporal positions stated (i.e. fundamental frequency band=1, first harmonic=2 etc).
- Rows 19-29: List the fundamental frequency measurements, taken at the temporal positions stated, used to calculate Mean frequency (Row 31) and the Coefficient of Frequency Modulation (Row 33) using the formula listed in the publication.
- Rows 35 and 36: List the cursor error margins of the acoustic analysis program I used.

Columns B-P - Give details of the above mentioned acoustic characteristics for 15 replicate calls from each of the 9 females sampled.

附文摘要如下：

声音识别可能是海豹科（phocid）母兽与幼崽在哺乳期维持联系的关键因素。若声音识别发挥作用，发声者需发出具有个体独特性的叫声，且该叫声能被目标接收者识别。母兽-幼崽声音识别在群居海狮科（otariids）动物中已得到广泛研究，且似乎是该科动物的典型特征。尽管相关研究数量较少，但对海豹科物种的实证研究显示其具有多种识别能力。本研究旨在探究威德尔海豹（Leptonychotes weddellii）雌性个体是否会发出具有个体独特性的“幼崽联络”叫声，且该叫声能在自然状态下的母婴团聚中发挥作用。研究分析了在南极洲韦斯特福尔丘陵（Vestfold Hills）记录的9只雌性个体的叫声，每只个体各15段。研究测量了1项时间特征、9项基频特征及5项频谱特征。交叉验证判别函数分析结果显示，母兽发出的叫声具有个体独特性，56%的叫声可被正确归属于对应个体。仅通过随机方式在新数据上达到此判别水平的概率极低。对南极洲麦克默多海峡（McMurdo Sound）附近记录的8次母婴团聚事件的分析进一步表明，这些“幼崽联络”叫声在自然团聚过程中发挥作用。行为分析还显示，在整个团聚过程中，幼崽主要负责建立和维持紧密联系。因此，本研究表明，威德尔海豹雌性个体发出的叫声具有足够的模式化程度，使幼崽能在团聚时识别出母兽，为母婴声音识别系统的功能性提供了证据。

A列-第1行：给出雌性个体的标记编号。
- 第3-33行：从频谱图中记录的声学测量指标列表。
- 第3-5行：以毫秒为单位记录的时间测量指标。
- 第7-12行：从基频获取的频率测量指标。第9-11行分别为沿基频时间轴1/4、2/4和3/4位置处的测量值。
- 第13-17行：给出指定时间位置处能量最高的频段编号（例如：基频频段=1，一次谐波=2等）。
- 第19-29行：列出指定时间位置处的基频测量值，这些值用于根据文献中列出的公式计算平均频率（第31行）和频率调制系数（第33行）。
- 第35-36行：列出所用声学分析程序的光标误差范围。

B-P列：给出所采样的9只雌性个体各15次重复叫声的上述声学特征详情。