Dear MARMAM community, We would like to announce the publication of our recent article: “Site Fidelity and Residency Patterns of Rough-Toothed Dolphins (Steno bredanensis) in Madeira Island Using Photo-Identification" This study presents the first assessment of site fidelity and residency patterns of rough-toothed dolphins in the Madeira region using photo-identification. Our findings provide new insights into the ecology and habitat use of this little-studied species, while establishing valuable baseline knowledge to support future research and conservation efforts. Abstract: The rough-toothed dolphin (Steno bredanensis) is distributed in warm waters worldwide, yet its spatial ecology remains poorly understood, especially in the Eastern North Atlantic. This study presents the first assessment of site fidelity and residency patterns for the species in this region, using year-round photo-identification data collected in Madeira Island between 2016 and 2024. A total of 1092 captures from 637 individuals showed that 62.5% were captured only once. The remaining individuals showed that 26.1% were recaptured intra-annually and 19.6% interannually (mean = 3 captures, SD = 1, range = 2–10), with a maximum recapture interval of 8 years. The proportion of distinctive marked dorsal fins was 51.1% (SD = 6.4%). Lagged Identification Rates, based on a model incorporating emigration and reimmigration, estimated that 28 individuals were present in the study area during the summer (July–August), with a mean stay of 6.4 days and an absence of 626 days. The Standardized Site Fidelity Index indicated low association (mean = 0.0057, SD = 0.0065) with the area. Overall, rough-toothed dolphins appear to be mainly transients or occasional visitors, suggesting high mobility and limited temporal association with the southern waters of Madeira, mainly during the summer. These findings provide new insights for guiding conservation strategies for rough-toothed dolphins in the Macaronesia biogeographic region. Citation: Raffaelli, C., A. Sambolino, R. Ferreira, R. Alves, E. Hamard, A. Marçalo, F. Alves, 2026. “Site Fidelity and Residency Patterns of Rough-Toothed Dolphins (Steno bredanensis) in Madeira Island Using Photo-Identification.” Marine Mammal Science42, no. 3: e70223. https://doi.org/10.1111/mms.70223. The article is available here: https://onlinelibrary.wiley.com/doi/10.1111/mms.70223 A PDF of the paper can be provided upon request. Best regards, Claire Raffaelli Research Technician MARE – Madeira University of Madeira ARDITI - Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação Edif. Madeira Tecnopolo, Piso - 2 Caminho da Penteada 9020-105 Funchal Portugal