The Self-Stranding Behavior of a Killer Whale ( Orcinus orca ) in Inner Danish Waters and Considerations concerning Human Interference in Live Strandings

• Published in: Animals
• Main Authors: Aage Kristian Olsen Alstrup, Charlotte Bie Thøstesen, Kirstin Anderson Hansen, Christian Sonne, Carl Christian Kinze, Lars Mikkelsen, Annika Thomsen, Peter Povlsen, Hanne Lyngholm Larsen, Anne Cathrine Linder, Sussie Pagh
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2023
• Subjects: behavior; euthanasia; killer whale; life stranding; rescue operation; strandings; Veterinary medicine; SF600-1100; Zoology; QL1-991; Killer Whale; Orca; Orcinus orca; Killer whale
• Online Access: https://doi.org/10.3390/ani13121948; https://doaj.org/article/a8bd0a16eb7c43389989a9c14a61c183

The rescue attempts of stranded whales and euthanasia considerations must include condition assessments of the individual involved, but this is challenged by our insufficient knowledge about the health statuses of these whales. Here, we describe three separate strandings of a young male killer whale ( Orcinus orca ) in shallow Danish waters during 2021–2022. During the first two stranding events, the whale exhibited remarkable behavior and, after refloating attempts and several kilometers of swimming, it returned to shallow water. This suggests that it actively chose to be in this shallow water, perhaps to ensure free airways and respiration. During the last stranding, it stayed in shallow water for 30 days, during which, euthanasia was considered due to its seemingly worsened condition, including a collapsed dorsal fin. However, suddenly, the whale swam away and, a year later, he was seen alive, confirming that euthanasia would have been the wrong decision. This case raises an important question as to when and under what circumstances active human interventions, such as refloating attempts, should be launched and when euthanasia should be carried out. Every stranding is unique and decisions should be based on thorough considerations of the animal’s health and the chance of a successful rescue.