Male sperm whale (Physeter macrocephalus) coda production and coda-type usage depend on the presence of conspecifics and the behavioural context

Sperm whale ( Physeter macrocephalus L., 1758 (= Physeter catodon L., 1758)) codas serve a communication function, but the message they carry remains unknown. Very few codas and extremely few coda types are available from males. For 7 years we studied the coda occurrence and the coda types produced by 15 males in different behavioural and encounter contexts. Of the 67 encounters, 615 codas were produced by nonsolitary males. Codas occurred in 60% of the nonsolitary encounters and 36% of the dive cycles. Four hundred and ninety codas have been categorized into 8 coda families and 25 distinctive coda types. Both the coda type used and the dive cycle phase in which codas occurred strongly depended on the behavioural context. This is the first time that coda types have been associated with particular behavioural contexts. The “Three plus” family coda types were mainly used by ascending or descending whales in feeding dive cycles. The “Regular” and “Progressive” families were used almost exclusively by interacting whales. The “Root” coda family was used exclusively at surface, mainly in altered dive cycles. The coda types used in these three behavioural contexts seem to carry different messages and are proposed to be named “dive cycle codas”, “social codas”, and “alarm codas”, respectively.