Last Calls of an Out-of-Habitat Killer Whale (Orcinus orca) in the Seine River.

The article focuses on the acoustic behavior of a lone killer whale (Orcinus orca) observed outside its natural habitat in the Seine River, France, in May 2022, shortly before its death. Acoustic recordings revealed predominantly pulsed calls, including both monophonic and biphonic stereotyped call types, often repeated in sequences, which may reflect contact-seeking behavior during social isolation and physiological distress. The whale exhibited poor physical condition, likely due to prolonged starvation and freshwater exposure, and no other killer whales were detected nearby. The study highlights the potential of acoustic monitoring as a complementary, non-invasive tool to assess the condition and behavior of out-of-habitat or distressed cetaceans, recommending its integration into rescue and conservation protocols to improve welfare outcomes. [Extracted from the article]