Dear MARMAM community, My co-authors and I are very pleased to announce the publication of our new paper in Peerj journal. Carlón-Beltrán Ó, Viloria-Gómora L, Urbán R. J, Martínez-Aguilar S, Antichi S. 2023. Whistle characterization of long-beaked common dolphin (*Delphinus delphis* *bairdii*) in La Paz Bay, Gulf of California. PeerJ 11:e15687. http://doi.org/10.7717/peerj.15687 Abstract Long-beaked common dolphin (*Delphinus delphis bairdii*) distribution is limited to the Eastern North Pacific Ocean. Its whistle repertoire is poorly investigated, with no studies in the Gulf of California. The aim of the present study is to characterize the whistles of this species and compare their parameters with different populations. Acoustic monitoring was conducted in La Paz Bay, Gulf of California. Recordings were inspected in spectrogram view in Raven Pro, selecting good quality whistles (n = 270). In the software Luscinia, contours were manually traced to obtain whistle frequencies and duration. Number of steps, inflection points and contour type were visually determined. We calculated the descriptive statistics of the selected whistle parameters and we compared the results with a dolphins population from the Eastern Pacific Ocean. Permutational multivariate analysis of variance (PERMANOVA) was performed to test the intraspecific variation of the whistle parameters among groups. In the present study the mean values (± SD) of the whistle parameters were: maximum frequency = 14.13 ± 3.71 kHz, minimum frequency = 8.44 ± 2.58 kHz and duration = 0.44 ± 0.31 s. Whistles with the upsweep contour were the most common ones (34.44%). The coefficient of variation (CV) values for modulation parameters were high (>100%), in accordance with other studies on dolphins. Whistle parameters showed significant differences among groups. Finally, ending and maximum frequencies, duration and inflection points of the whistles recorded in the present study were lower compared with the parameters of the long-beaked common dolphins from the Eastern Pacific Ocean. This study provides the first whistle characterization of long-beaked common dolphin from the Gulf of California and it will help future passive acoustic monitoring applications in the study area. The paper is open access and can be downloaded at: https://peerj.com/articles/15687/ If you have any questions regarding our work please contact the email: santichi_20@alu.uabcs.mx , lviloria@uabcs.mx Kind regards, Simone Antichi -- PhD candidate Departamento de Ciencias Marinas y Costeras, Universidad Autónoma de Baja California Sur, La Paz, Baja California Sur, Mexico. email: santichi_20@alu.uabcs.mx cell: +52 612 228 5196