Mammals
Atlantic White-Sided Dolphin
Leucopleurus acutus · also called Atlantic white-sided dolphins
Cutting through cold North Atlantic water alongside a pod of pilot whales, an Atlantic white-sided dolphin’s bold yellow-tan side patch flashes briefly at the surface, a robust, cold-tolerant species thriving in conditions many other dolphins would find far too harsh.
Overview
The Atlantic white-sided dolphin, Leucopleurus acutus, is a robust, cold-tolerant dolphin native to cool temperate and subarctic waters across the North Atlantic, including the eastern coast of North America and coastlines of northern Europe. Its bold multi-toned colour pattern, unusual tolerance for cold water, and frequent association with other whale species make it one of the more physically distinctive and socially flexible dolphins found in the North Atlantic.
A dolphin built for colder water
While many dolphin species stick to warmer tropical and temperate seas, the Atlantic white-sided dolphin has instead adapted to thrive in considerably colder North Atlantic waters, a tolerance that sets it apart from more warmth-dependent relatives.
Status
Least Concern, widespread and stable across suitable cool water habitat throughout the North Atlantic.
Atlantic White-Sided Dolphin: common questions
Why does the Atlantic white-sided dolphin tolerate such cold water?
This species has adapted to tolerate considerably colder water than many other dolphin species, an adaptation that allows it to remain in cool North Atlantic and subarctic waters that would be inhospitable to more warmth-dependent dolphin relatives found in tropical and temperate regions.
How can you identify an Atlantic white-sided dolphin?
Look for a bold, multi-toned colour pattern including a distinctive pale yellow or tan patch along the sides toward the tail, combined with a comparatively robust, sturdy body build that sets this species apart from the more slender profiles of several other North Atlantic dolphins.
Does the Atlantic white-sided dolphin travel with other whale species?
Yes, this species is often observed travelling in mixed groups alongside other cetacean species, including pilot whales, a behaviour that likely allows both species to take advantage of shared feeding opportunities in productive North Atlantic waters.
How large can Atlantic white-sided dolphin groups get?
This species is highly social, typically travelling in groups ranging from a handful of individuals to several hundred, with larger aggregations sometimes forming in especially productive feeding areas where prey is particularly abundant.