Mammals
Hourglass Dolphin
Lagenorhynchus cruciger · also called hourglass dolphins
Riding the bow wave of a research vessel in one of the most remote stretches of the Southern Ocean, an hourglass dolphin’s sharply narrowing black-and-white pattern flashes at the surface, a species so rarely encountered that much of its basic biology remains only partly understood.
Overview
The hourglass dolphin, Lagenorhynchus cruciger, is a striking, cold-tolerant dolphin native to cold circumpolar waters surrounding Antarctica, typically found at subantarctic to Antarctic latitudes. Its distinctive hourglass-shaped colour pattern, tolerance for some of the coldest waters any dolphin species inhabits, and status as one of the more poorly studied dolphins due to its remote habitat make it one of the more scientifically elusive and visually striking cetaceans found anywhere on Earth.
A dolphin at the edge of the world
Circling some of the most remote, rarely visited waters on the planet, the hourglass dolphin has managed to remain genuinely mysterious even in an era when most large marine mammals have been studied extensively.
Status
Least Concern, present across suitable cold circumpolar habitat surrounding Antarctica, though its remote range makes precise population assessment difficult.
Hourglass Dolphin: common questions
Why is it called the hourglass dolphin?
This species displays a striking black-and-white colour pattern that narrows sharply along the sides in a shape resembling an hourglass, a distinctive marking that gives the species its common name and makes it fairly easy to identify where it occurs.
Why is the hourglass dolphin so poorly studied?
This species remains comparatively poorly studied because of the extreme remoteness and difficulty of accessing its usual Southern Ocean habitat, circling Antarctica far from most shipping routes and research effort, making sustained observation and study genuinely challenging for researchers.
Does the hourglass dolphin tolerate cold water well?
Yes, this species is one of the relatively few dolphin species found regularly in the cold waters surrounding Antarctica, tolerating conditions that would exclude many warmer-water dolphin relatives found in more temperate or tropical regions.
Is the hourglass dolphin acrobatic?
This species is a fast, energetic swimmer, frequently observed riding the bow waves of ships and showing considerable surface activity when encountered, a behaviour that has made sightings by researchers and sailors genuinely memorable despite the species' overall rarity of observation.