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.

源自所附论文的摘要：声纹识别在哺乳期间维持海豹科（Phocidae）母子纽带中可能发挥关键作用。要实现声纹识别功能，发声个体必须发出具备个体特异性的鸣声，且能被目标接收者识别。针对群居海狮科（Otariidae）物种的母子声纹识别研究已相当广泛，该特征被认为是海狮科的典型属性。尽管相关研究数量较少，但针对海豹科物种的实证研究已揭示了多样的识别能力。本研究旨在探究威德尔海豹（Leptonychotes weddellii）雌性个体是否会发出具备个体特异性的"幼崽联络鸣声"，并在自然母子团聚过程中发挥功能。研究分析了南极韦斯特福尔德丘陵地区9只雌性威德尔海豹的各15次鸣声，共测量了1项时域特征、9项基频特征以及5项频谱特征。经交叉验证的判别函数分析（Discriminant Function Analysis）结果显示，雌性个体可发出具备个体特异性的鸣声，其中56%的鸣声被正确归类至对应个体。仅凭随机概率达到该区分精度的可能性极低。对南极麦克默多海峡附近记录的8次母子团聚行为的分析进一步证实，这类"幼崽联络鸣声"确实在自然团聚过程中发挥功能。行为分析还显示，幼崽在整个团聚过程中主要负责建立并维持紧密接触。因此，本研究证明威德尔海豹雌性个体发出的鸣声具备足够的刻板性，可让幼崽在团聚过程中识别亲代，为运行中的母子声纹识别系统提供了实证依据。列A - 第1行：标注雌性个体的标签编号。第3-33行：从声谱图中提取的声学测量指标列表。第3-5行：以毫秒为单位记录的时域测量指标。第7-12行：从基频提取的频率测量指标，其中第9-11行分别对应基频沿时域的1/4、2/4、3/4位置进行测量。第13-17行：标注在对应时域位置上能量最高的频带编号（即基频频带=1，第一谐波=2，以此类推）。第19-29行：列出在对应时域位置提取的基频测量值，用于按论文中给出的公式计算平均频率（第31行）与频率调制系数（第33行）。第35-36行：列出本次使用的声学分析程序的光标误差容限。列B-P：分别给出9只采样雌性个体各15次重复鸣声的上述声学特征详情。