Ecological divergence in movement and habitat use of long-finned pilot whales (Globicephala melas) across the subpolar North Atlantic

Abstract

Despite their widespread presence across the North Atlantic, it remains unclear how long-finned pilot whales ( Globicephala melas ) differ regionally in their movement patterns and habitat use, and what this means for population structure. Satellite transmitters attached to pilot whales in the Faroe Islands ( n = 11), East Greenland ( n = 6), and Iceland ( n = 2) between 2023 and 2025 revealed consistent regional differences in horizontal movements and habitat use. Whales tagged in the Faroe Islands displayed extensive offshore movements into deep oceanic waters more than 150 km from the coast. In contrast, whales tagged in East Greenland and Iceland mostly remained largely associated with shallower continental shelf waters and closer to the coast, with repeated use of the same shelf area across multiple years in East Greenland. Significant regional differences in displacement, bathymetry, and distance to coast indicate distinct oceanic and shelf-based movement strategies. These patterns are consistent with regional prey availability and distribution—shelf-associated whales exploit locally abundant species such as squid in East Greenland and possibly mackerel in Iceland, while whales undertaking long-distance oceanic movements target more widely distributed pelagic prey. Our results suggest ecological differentiation within a genetically homogenous North Atlantic population and emphasise the need to integrate movement ecology, genetics, and oceanography to better understand population structure and define meaningful management units in a rapidly changing subpolar ecosystem.

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