Codas are vocalisations produced by sperm whales (Physeter macrocephalus) in social settings consisting of a short series of clicks with a stereotyped time pattern and are identified as cultural markers for different sperm whale populations across the globe. The current study analysed data from the OνDE acoustic station, part of the NEMO-SN1, between 2005 and 2006 at 2000 m depth off the coasts of Catania, Italy, to monitor the soundscape. Codas were classified using parsimonious mixtures of multivariate contaminated normal distributions based on their absolute inter-click interval and number of clicks per coda. The models found 3 clusters for three-click codas, 4 for four-click patterns, and 1 for the five-click pattern, with 8 clusters divided into three families. Codas of the ‘3 + 1’ and ‘2 + 1’ families were the most represented for all years and months, and the summer months had the highest number of detections. This study integrates well within the current knowledge of the coda repertoire of Mediterranean sperm whales and offers a new study location placed in the Ionian Sea, a strategic point where individuals could pass from the Western to the Eastern basin.
Sperm whales, bioacoustics, animal culture, codas