A total of 109 recordings aiming to identify Bryde's whale calls were collected from the Gulf of California, Mexico, during field trips performed from January 2010 to June 2014. Vocalizations were recorded only when no calves were observed. Four types of calls were identified. Calls similar to the Be4 call type previously reported for the Eastern Tropical Pacific region and South of California were recorded. In addition, three calls, not reported in previous studies of the Bryde's whale, have also been identified. The identification of these calls, which were labeled Be10, Be11, and Be12, enables expansion of the known acoustic repertoire of this species, which is currently poorly documented. The identification of three previously unreported calls and the confidence given by careful visual confirmation of the whale species and number of individuals contribute to make this study a significant contribution toward the acoustic monitoring of Bryde's whale.
The authors would like to thank the PRIMMA-UABCS members (Programa de Investigación de Mamíferos Marinos-Universidad Autónoma de Baja California Sur) who participated in data collection, Ira Fogel of CIBNOR (Centro de Investigaciones Biológicas del Noroeste, S. C.) for providing editorial services, and Raymond Wolfe of Cork Institute of Technology for his help with the final document. This research was carried out under the scientific research Permit Nos. SGPA/DGVS/08434/09–2009, SGPA/DGVS/0073411–2011, and SGPA/DGVS/0099/14–2014 from the Secretaria de Medio Ambiente y Recursos Naturales of Mexico. Funding was provided by Consejo Nacional de Ciencia y Tecnología (CONACYT Project No. 134251-Sep-CONACYT) and WWF-TELCEL. L.V.G. was a recipient of a fellowship grant (CONACYT 165753).
I. INTRODUCTION II. METHODS A. Recordings B. Signal pre-processing III. RESULTS IV. DISCUSSION