Dear MarMam community,

On behalf of my co-authors, I am pleased to share our latest article published in Marine Mammal Science: First identification of stereotyped whistle contour types by Pseudorca crassidens (Raul Rio & Hiram Rosales-Nanduca)

Dolphins use personalized vocalizations, known as signature whistles (SW), to transmit the senders' identity to their surroundings. The present study is the first to provide acoustic evidence that false killer whales (Pseudorca crassidens) produce stereotyped whistle contour types. Acoustic recordings were obtained opportunistically from a false killer whale group, living seasonally in Mexican Pacific waters. Out of the 410 whistles extracted, 69.0% (283) were classified as stereotyped whistles (STW), 44.9% of them (127) met the SIGID bout criteria for SW. We suggest that at least one third (31.0%) of coastal false killer whale whistles produced by free-ranging animals from La Paz Bay, Gulf of California, could be possible signature whistles (PSW). The visual similarity in value judgment by naïve external observers has confirmed the adopted PSW classification type, with perfect overlap and suggested short-term whistle stability. Research about the individual recognition skills of these animals could provide valuable information for the yet limited understanding of this species' social structure in La Paz Bay, especially because recent genetic evidence shows unique haplotypes for this population.