Strandings and at sea observations reveal the canary archipelago as an important habitat for pygmy and dwarf sperm whale

Abstract

Cetaceans are a critical component of marine ecosystems, acting as top predators in mesopelagic trophic webs. In the Macaronesian biogeographical region, cetacean populations face threats from various anthropogenic activities. Evaluating cryptic oceanic species like kogiids whales is challenging due to insufficient biological and ecological data, making conservation assessments and management efforts harder to achieve. Kogia breviceps and K. sima comprising the family Kogiidae, are morphologically similar, widely distributed, and elusive, with most information originating from stranded specimens and few at sea observations. This study examines data from Kogia species stranded in the Canary Islands between 1977 and 2024 and analyzes sighting data obtained between 1999 and 2024. Between 1977 and May 2024, there were 111 stranding events involving 114 kogiid individuals along the Canary Islands’ coasts: 86 events (88 individuals) were pygmy sperm whales, 14 events (15 individuals) were dwarf sperm whales, and 11 events with 11 individuals, were unidentified Kogia species. Additionally, 36 kogiid sightings were recorded, of which 34 originated from dedicated surveys and 2 from opportunistic sightings. Of these sightings, 14 (39%) were K. breviceps, 9 (25%) were K. sima, and 13 (36%) were unidentified Kogia. Twenty-nine sightings (80.5%) of kogiids were recorded in the waters off the eastern coast of the islands of Lanzarote and Fuerteventura. The data indicate that the waters around the Canary Islands are an important habitat for Kogia whales. The findings establish a baseline for future research and underscore the necessity of accurately assessing conservation pressures on pygmy and dwarf sperm whales in the region.