Dear all, We are happy to announce this publication in the Journal of The Acoustical Society of America. For the first time in the world deterministic chaos was tested on dolphins. Abstract: Animal vocalizations have nonlinear characteristics responsible for features such as subharmonics, frequency jumps, biphonation, and deterministic chaos. This study describes the whistle repertoire of a short-beaked common dolphin (Delphinus delphis) group at Brazilian coast and quantifies the nonlinear features of these whistles. Dolphins were recorded for a total of 67 min in Cabo Frio, Brazil. We identify 10 basic categories of whistle, with 75 different types, classified according to their contour shape. Most (45) of these 75 types had not been reported previously for the species. The duration of the whistles ranged from 0.04 s to 3.67 s, with frequencies of 3.05–29.75 kHz. Overall, the whistle repertoire presented here has one of the widest frequency ranges and the greatest level of frequency modulation recorded in any study of D. delphis. All the nonlinear features sought during the study were confirmed, with at least one feature occurring in 38.4% of the whistles. The frequency jump was the most common feature (29.75% of the whistles) and the nonlinear time series analyses confirmed the deterministic chaos in the chaotic-like segments. These results indicate that nonlinearities are a relevant characteristic of these whistles, being important in acoustic communication. Luciana Duarte de Figueiredo, Israel Maciel, Flavio M. Viola, Marcelo A. Savi, Sheila M. Simão; Nonlinear features in whistles produced by the short-beaked common dolphin (*Delphinus delphis*) off southeastern Brazil. *J Acoust Soc Am* 1 April 2023; 153 (4): 2436–. https://doi.org/10.1121/10.0017883 Do not hesitate to contact us (oceanmaciel@gmail.com / luciana.figueiredo@ifrj.edu.br) in case of further questions or requirements. Kind regards, Israel Maciel Dr. Israel Maciel Pós-doutorando - Departamento de Ecologia - UERJ Laboratório de Ecologia de Aves e Comportamento Animal Laboratório de Ecologia e Conservação Marinha (ECoMAR) - UFRJ ------- Post-doctoral fellow - Ecology department - UERJ (RJ, Brazil) Ecology of Birds and Animal Behavior Lab Marine Ecology and Conservation Lab - UFRJ (RJ, Brazil) http://lattes.cnpq.br/6836446340258869 https://orcid.org/0000-0003-1744-2721 https://lablbec.wixsite.com/lbec https://labecoavesuerj.wixsite.com/labecoaves