Variations in the vocal repertoire of the manatee in the Caribbean (Trichechus manatus manatus)

Abstract

While different life history parameters for the manatee have been well studied in Florida, little is known about these aspects of manatee biology in the Caribbean. As part of a multifaceted study in Antillean manatee life history, the geographical and individual variability in vocal repertoires of Antillean manatees from Puerto Rico and the Dominican Republic were examined and compared to the repertoire of the Florida manatee. Differences in structural sound characteristics (frequency, duration, and relative power of each harmonic), usage (number of call types), and the associated behavior were studied from recordings of wild and captive animals. Over 100 h of recording were obtained from six different natural localities in Puerto Rico and one natural locality in Florida. Captive manatees were recorded in the Dominican Republic (1), in Puerto Rico (2), and Florida (13), in addition to recording seven semicaptive individuals in Florida. The recording of underwater vocalizations has been suggested as a useful tool for the study of marine mammals distribution. In the turbid waters of rivers, bays, and lagoons where manatees congregate in the Caribbean, these acoustic data might be useful for estimating population distribution and habitat use.