Spinner Dolphins of Hawaii And the Rest of the World

They jump, they spin, and they glide through the waters with grace and ease. These are the species of toothed whales known as Spinner Dolphins, one of the more than 42 dolphin species that live on the Earth. Absolutely amazing to watch, they are one of the most playful of all dolphins. If you are heading to Hawaii and asking about marine life you will likely hear about the Spinners first.

Not very big, the Spinner Dolphins will grow to be about six to seven feet long with a maximum weight of about 200 pounds, unlike the local Bottlenose dolphins of Marco Island that can reach 10 feet long and weigh 600 pounds. The stealthy Spinners have a unique behavior pattern in Hawaii. You will see them along the shallow coastal waters during the day, but they travel offshore at night to feed.

After a night of catching fish and squid, they will rest along the coastline in the morning, being a bit more playful in the afternoon hours.

During the day, you might see a grouping of about 10 to 20 traveling together, but they come into a larger group, or “pod,” at night for fishing. Gathering food in great numbers is necessary for them. Diving to depths up to 1,000 feet, some of the dolphins will circle a school of fish, keeping them in a tight ball while the other dolphins dart into the ball feeding.

Their primary food source is Lanternfish. These fish are known for their bioluminescence or emission of light. This chemical reaction allows colors to be produced on the exterior of the fish, making them an easy target for the Spinner Dolphins. The Lanternfish live at depths of 900 to 2,500 feet during the daytime, rising to depths of 30 to 350 at night to feed on zooplankton. This is known as a “vertical” migration.

Once again, after feeding at night, these dolphins return to the shallow coast during the day to rest and socialize. Just like many other dolphin species, playtime and socialization is a big part of their personalities. Part of their playing, as well as communicating, is the spinning motion they display.

They will actually begin spinning before they reach the surface and, once airborne, can complete four to five full rotations reaching heights up to 10 feet before landing on the water’s surface. Lucky humans who happen upon a large pod of Spinners might witness hundreds of the dolphins spinning at the same time!

This species has a lifespan of about 20 to 25 years. Moms will produce one calf at a time about every two to three years, nursing a calf for two years. The gestation period is approximately 11 months. The calf will then take its place in the pod. Females mature sexually at about seven years old, while the males mature at about 10 to 12 years old. 

They communicate through touch but also rely on echolocation and whistles. Mating habits, like Bottlenose dolphins, are very promiscuous. They will mate without selection.

Both males and females stay within the pod structure but do not form a permanent bond. This species is found primarily in tropical and subtropical waters.

Hawaii seems to be best known to people for its Spinner dolphin population. However, this species can be found in other parts of the world. Tropical and subtropical waters exist around the planet so the Pacific, Atlantic, and Indian Oceans are all home to Spinners. In fact, close to our home here in Florida, the Gulf of Mexico has one of the largest populations of Spinner Dolphins! There are about 3,000 in the Hawaiian Islands, while the northern section of Florida’s panhandle is home to as many as 11,000! The Atlantic and Indian Oceans both see large populations of Spinners as well with the largest population in the seas around Malaysia, home to about 30,000 Spinners.

Although there have been sightings of this species in the southwest Gulf of Mexico, the primary concentration of this stock is in the northern Gulf waters, around the panhandle to Alabama and Louisiana. Bottlenose dolphins, by far, are the most common species found along the shores, with an estimated population of 7,000. However, along the 

Continental shelf, where the water becomes deep, that’s where you’ll find the Spinners. 

These acrobats can be found around the world, in tropical and subtropical waters. They are absolutely amazing to watch, spinning so quickly and with great agility. If you’re lucky, maybe you’ll see one in the Gulf or Atlantic Ocean. But, almost certainly, if you go to Hawaii, keep a lookout along the coastlines during the day. They will rest in the morning but come afternoon, watch for those leaps!