Bag-of-calls analysis reveals group-specific vocal repertoire in long-finned pilot whales

• Main Authors: Vester, Heike, Hammerschmidt, Kurt, Timme, Marc, Hallerberg, Sarah
• Format: Report
• Language: unknown
• Published: arXiv 2014
• Subjects: Quantitative Methods q-bio.QM; FOS Biological sciences; Norway; Northern Norway
• Online Access: https://dx.doi.org/10.48550/arxiv.1410.4711; https://arxiv.org/abs/1410.4711

Besides humans, several marine mammal species exhibit prerequisites to evolve language: high cognitive abilities, flexibility in vocal production and advanced social interactions. Here, we describe and analyse the vocal repertoire of long-finned pilot whales (Globicephalus melas) recorded in northern Norway. Observer based analysis reveals a complex vocal repertoire with 140 different call types, call sequences, call repetitions and group-specific differences in the usage of call types. Developing and applying a new automated analysis method, the bag-of-calls approach, we find that groups of pilot whales can be distinguished purely by statistical properties of their vocalisations. Comparing inter-and intra-group differences of ensembles of calls allows to identify and quantify group-specificity. Consequently, the bag-of-calls approach is a valid method to specify difference and concordance in acoustic communication in the absence of exact knowledge about signalers, which is common observing marine mammals under natural conditions. : under review