Hourglass dolphins, sometimes known as skunk dolphins, are small dolphins of the Delphinidae family that live in the Antarctic and sub-Antarctic seas. Hourglass dolphins are often mistaken for baby killer whales because of the similar black and white patches covering the dolphin’s body.
Derivation: The scientific name is Lagenorhynchus cruciger. Lagenorhynchus means “bottlenose,” while cruciger means “orb and cross” (referring to the dolphin’s black regions that resemble a cross).
Taxonomy ID: 180447
Classification
| Kingdom | Animalia |
| Class | Mammalia |
| Order | Cetacea |
| Suborder | Odontoceti |
| Family | Delphinidae |
| Genus | Lagenorhynchus |
| Species | L. cruciger |
Characteristics
Hourglass dolphins, as the name suggests, have black and white markings on their bodies that resemble an hourglass. These dolphins have short, stocky bodies with large, curved dorsal fins. Male hourglass dolphins grow to be around 5’7″ long, while females grow to be about 5’1. An adult hourglass dolphin weighs around 242 pounds, and their tooth count ranges from 54 to 70 in the lower jaw and 52 to 68 in the upper jaw.
The hourglass illusion appears where the first white patch starts around the dolphin’s mouth and extends across the eye before narrowing and finishing at the dorsal fin. The second white patch goes all the way from the dorsal fin to the tail.
Like most dolphin types, hourglass dolphins are sociable creatures. They swim at a speed of about 16 mph in pods of five to 14 individuals, but groups of 100 or more have been spotted. They’re seldom seen alone.
They also interact with other whales, such as fin whales, minke whales, southern bottlenose whales, and even killer whales.
Where Do They Live?
Hourglass dolphins are usually found in the southern waters of the Antarctic region. Their main geographic range is between Macquarie Island and South America, near the Antarctic Front.
They’re often found in water temperatures ranging from 32 to 44°F, but they prefer cooler waters ranging from 32 to 33°F — which is why they migrate to cooler southern seas in the summer and farther north in the winter.
How Many Hourglass Dolphins Are Left?
Hourglass dolphins are estimated to have a current population of roughly 140,000.
What Do They Eat?
Hourglass dolphins are piscivores and molluscivores. Their diet mainly consists of fish, squid, and crustaceans. They like to gather in large groups and feed near the surface, making them easily spotted by research vessels.
Are They Endangered?
According to the IUCN Red List, hourglass dolphins are listed as Least Concern (LC).
Threats
Their habitats are fairly remote, so hourglass dolphins are not subject to hunting or other common dangers in more human-populated seas. The largest threat to hourglass dolphins is climate change.
Protection
The hourglass dolphin is protected under the Marine Mammal Protection Act.
Discovery
Hourglass dolphins were discovered in 1824 by Jean René Constant Quoy and Joseph Paul Gaimard. The two French surgeons and naturalists were leading an expedition in the Antarctic when they identified the species.
