Greetings MARMAM, I am pleased to share the news of our newest publication in Scientific Reports on comparisons of the acoustic behavior of three manatee species. <https://www.nature.com/articles/s41598-022-23321-7> Manatee calf call contour and acoustic structure varies by species and body size -… <https://www.nature.com/articles/s41598-022-23321-7> Vocal activity and signal characteristics of mammals are driven by several factors that result in both stability and plasticity over multiple time scales. <https://www.nature.com/articles/s41598-022-23321-7> nature.com <https://www.nature.com/articles/s41598-022-23321-7> [image: Mixmax] <https://www.mixmax.com/?ref=Website%20preview&userId=6Amb6EMgzCtFYX7ua> *Abstract* Vocal activity and signal characteristics of mammals are driven by several factors that result in both stability and plasticity over multiple time scales. All three extant species of manatee communicate with several calls that are especially important for maintaining contact between cows and calves. Determining if calf calls differ across manatee species will provide insights into the evolution of species-specific acoustic communication traits. We investigated the interspecific differences in the vocalizations of calves of Amazonian manatees (*Trichechus inunguis*) and the two subspecies of the West Indian manatee (*T. manatus*). Vocalizations of individual calves were recorded in rehabilitation centers in Brazil, Puerto Rico, the United States, and Mexico. The acoustic structure of calls produced by manatee calves varied between species and with body size. Amazonian manatee calves produced shorter calls with multiple notes at higher frequency while West Indian calves produced modulated calls that were lower in frequency and longer in duration. Smaller West Indian calves produced frequency modulated, hill-shaped calls that flattened with an increase in body length. Our results provide evidence for divergence in the ontogeny of vocalizations across *T. manatus* and *T. inunguis* and suggest variation in body size contributed to the evolution of differences in the characteristics of their calls. Brady, B., Ramos, E. A., May-Collado, L., Landrau-Giovannetti, N., Lace, N., Arreola, M. R., ... & Sousa-Lima, R. S. (2022). Manatee calf call contour and acoustic structure varies by species and body size. Scientific Reports, 12(1), 1-10. Best wishes, *Eric Angel Ramos, Ph.D.* Postdoctoral Research Associate at The Rockefeller University Scientist at FINS (Fundación Internacional para la Naturaleza y la Sustentabilidad) Student Member-At-Large for the Society for Marine Mammalogy Member of the IUCN SSC Sirenian Specialist Group for Mesoamerica www.finsconservation.org <https://finsconservation.org/> E-mail: eric.angel.ramos@gmail.com/ eramos@rockefeller.edu Cell/WhatsApp <https://wa.me/13473365567>: +1-347-336-5567 (USA) Skype: ericangelramos Facebook <https://www.facebook.com/ericangelramos> | Twitter <https://twitter.com/EricAngelRamos> | Instagram <https://www.instagram.com/eric.angel.ramos/> ResearchGate <https://www.researchgate.net/profile/Eric_Ramos> | ORCiD <https://orcid.org/0000-0003-4803-3170> | LinkedIn <https://www.linkedin.com/in/eric-angel-ramos-aa9b4915/>