Spinner dolphin

How it lives

In Hawaiʻi, spinner dolphins feed offshore at night on small fish, shrimp and squid, then rest in calm, sandy bays by day for about four to five hours. Large schools gather to feed at night and split into smaller groups to rest. Pregnancy lasts about 11 months, with a calf about every 3 years, and they can live about 20 to 25 years. Other populations can live differently, so this pattern is not the same everywhere.

Where it goes

Island-associated spinner dolphins in Hawaiʻi move offshore at night to feed and come back to shallow bays to rest during the day. Coastal Hawaiian stocks mostly stay within about 10 nautical miles of their islands. Movements of other populations can be different.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

Spinner dolphins have four subspecies, with different sizes, ecology and history. The eastern spinner of the tropical eastern Pacific is assessed as Vulnerable on its own, after heavy losses in past tuna fishing. Hawaiʻi has five island-associated stocks plus an offshore stock, with little breeding between them. Timor-Leste's 2016 survey recorded both the typical spinner and the smaller dwarf spinner, and a mid-2000s study counted about 150 dolphins in the Moʻorea community, which is not a current count.