Dear Colleagues, The paper ‘‘Decreased resting and nursing in short-finned pilot whales when exposed to louder petrol engine noise of a hybrid whale-watch vessel*'* is published today in the journal *Scientific Reports*. You can download the pdf from this link: http://nature.com/articles/s41598-021-00487-0. The work is the result of the joint effort of researchers from the University of La Laguna (Spain), Aarhus University (Denmark) and University of Iceland (Iceland), as well as a collaborating whale watching operator from Tenerife, Canary Islands. Authors: Patricia Arranz, Maria Glarou, Kate R. Sprogis. Previous research has found that noise produced by whale-watch vessels can affect whale behaviour. However, despite global effort for implementing best-practice principles, to date, there are no regulations on whale-watch vessel noise levels. We used drones to observe the behaviour of short-finned pilot whale mother and calf pairs off the coast of Tenerife, Spain. We found that, compared to those not approached by a vessel, mothers who were approached by a vessel with petrol engines spent on average 29% less time resting and 81% less time nursing their calves. There were no significant effects on behaviour from the vessel when using the quieter electric engines. These results suggest that these behavioural changes could increase the energy consumption of mothers and reduce calf energy intake, with potential negative implications for calf survival. The findings demonstrate that, even if whale-watch vessels comply with current guidelines, louder engines can have a greater impact on whale behaviour. We suggest that noise produced by whale-watch vessels be minimised and the noise levels from whale-watch vessels considered in existing guidelines, in order to limit disturbance to whales. Reference: P. Arranz, M. Glarou, K. Sprogis. 2021. Decreased resting and nursing in short‑finned pilot whales when exposed to louder petrol engine noise of a hybrid whale‑watch vessel. Scientific Reports, 11:21195 Please feel free to contact us if you have any questions. Kind regards, Patricia, Maria and Kate CONTACT: Patricia Arranz (University of La Laguna, Tenerife, Spain) Email: arranz@ull.edu.es