Dear colleagues, My co-authors and I are pleased to announce the publication of our study entitled "Seasonal trends and diel patterns of downsweep and SEP calls in Chilean blue whales" in the Journal of Marine Science and Engineering. Authors: Redaelli Laura, Mangia Woods Sari, Landea Rafaela, Sayigh Laela. The abstract can be found below and the full open access paper at: JMSE | Free Full-Text | Seasonal Trends and Diel Patterns of Downsweep and SEP Calls in Chilean Blue Whales (mdpi.com) <https://www.mdpi.com/2077-1312/10/3/316> For any further information, please reach out to laura.redaelli.95@gmail.com Best regards, Laura Abstract: To learn more about the occurrence and behaviour of a recently discovered population of blue whales, passive acoustic data were collected between January 2012 and April 2013 in the Chiloense ecoregion of southern Chile. Automatic detectors and manual auditing were used to detect blue whale songs (SEP calls) and D calls, which were then analysed to gain insights into temporal calling patterns. We found that D call rates were extremely low during winter (June–August) but gradually increased in spring and summer, decreasing again later during fall. SEP calls were absent for most winter and spring months (July–November) but increased in summer and fall, peaking between March and April. Thus, our results support previous studies documenting the austral summer residency of blue whales in this region, while suggesting that some individuals stay longer, highlighting the importance of this area as a blue whale habitat. We also investigated the daily occurrence of each call type and found that D calls occurred more frequently during dusk and night hours compared to dawn and day periods, whereas SEP calls did not show any significant diel patterns. Overall, these findings help to understand the occurrence and behaviour of endangered Chilean blue whales, enhancing our ability to develop conservation strategies in this important Southern Hemisphere habitat. -- *Laura Redaelli* Marine Biology MSc. Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands +393204681866