Abstract

Sperm whale (Physeter macrocephalus) is a globally distributed species known for forming matrilineal social groups composed of mature females, calves, and immature whales of both sexes. These groups typically remain in temperate and tropical waters, displaying long-term associations. As males reach puberty, their bonds with the matrilineal group weaken and they start migrating to higher latitudes towards foraging grounds. Previous photo-ID matches have documented male migrations for mating between the Azores and Norway, the Gulf of Mexico, and the Bahamas, but never all the way across the Atlantic. This study presents the first documented male sperm whale photo-identification match between Guadeloupe, Lesser Antilles and off Andøya in arctic Norway. The individual, identified as ID0261in the Whale2Sea catalogue, was first photographed by Marten Bril on September 2014, during a Whale2Sea whale-watching trip in the Bleik canyon (69°30’N, 15°25’E), a deep underwater canyon reaching 3000m. On 23 April 2022, the same individual documented as Pm145 in the OMMAG sperm whale catalogue was sighted off the leeward coast of Guadeloupe (16°11’N, 61°52’W) at 1000m depth by Cedric Millon of Cétacés Caraïbes on another whale-watching trip. This re-sighting was made possible by a sperm whale fluke photo-ID catalogue for the North Atlantic and Mediterranean, NAMSC. This allows images from different study areas to be matched, currently by Lisa Steiner, using Phlex & Match matching programs developed during the “Europhlukes” project. Additionally, the re-sighting highlights the value of citizen science initiatives in enhancing our understanding of behavioural ecology of sperm whales in the North Atlantic.