Common dolphins off Pico

The animal

The common dolphin, Delphinus delphis, also listed as the short-beaked common dolphin, is a small, fast oceanic dolphin that often travels in large, active groups. It shares a family with the orca, which is the largest member of that family, but the two could hardly look or behave more differently. Among the dolphins logged off Pico it is the one with the most records by a clear margin.

What the records show

OBIS holds 6,297 common dolphin records inside the box of sea around Pico that this site queries. Only the sperm whale has more. The records fall in eight months, March to October. June is the busiest, with 1,455 records, and May is almost level with it. July comes next, and the count then falls steadily through August, September and October. From November to February there are no records at all.

That is a broader season than the large baleen whales show. The fin and blue whales are logged mainly from March to June and fade out by late summer, while common dolphin records stay high well into August.

How to read that

These are records, not animals, and not a forecast. A record is one logged observation, and a large group of dolphins seen by several boats can produce several. Records also depend on who is out looking, and far more boats go out in the warmer months. Winter shows how thin the record gets. Even the sperm whale, the most-recorded species in this box, has at most a few dozen records in any winter month, so the dolphin's blank months are better read as months with little looking than as proof that no dolphins were there.

Conservation status

Wikidata, citing the IUCN Red List, gives the common dolphin's status as Least Concern. The species was described by Linnaeus in 1758.

Related

• All five species, and how the counts are built: whale and dolphin species off Pico.
• The other dolphins in the calendar, including Risso's and the Atlantic spotted dolphin, month by month: the season calendar.
• The approach rules and the licensed operators: whale watching on Pico.

Group size, body length and population figures are not given here, because none has been checked against a primary source.