Commerson's dolphin

(Cephalorhynchus commersonii)


Facts

Commerson's dolphin IUCN DATA DEFICIENT (DD)

 

Facts about this animal

This is one of the smallest dolphin species. Females are typically somewhat larger than males. South American Commerson's dolphins grow up to 1.52 m and 45-66 kg; those off the Kerguelen Islands are larger than those from the South American population at all ages, with maximum lengths of 1.68 m in males and 1.75 m in females, and a weight of up to 86 kg.

 

The Commerson's dolphin has a small stocky body with rounded, paddle-like flippers and no obvious beak. In adult individuals the head, fluke, dorsal fin, flippers and the rear part of the back are black. The rest of the body and the throat are white, apart from a black genital patch. The ears, located just behind the eyes, are small inconspicuous openings. Most individuals have 26 to 35 teeth on each side of both jaws, a total of 104 to 140 teeth.

 

Commerson’s dolphins have a well developed, keen sense of hearing. They rely as much on sound as they do on sight to hunt prey in the choppy, murky waters of their habitat. They are fast and maneuvrable swimmers also commonly seen wave-riding in the bows or wakes of high-speed boats, shoreline breakers or groundswells. They often swim upside down and feed in this position as well.

 

Commerson’s dolphins are typically found alone or in small groups of two to three animals and occasionally spotted in larger groups of 20 to 30 or more dolphins. They often hunt cooperatively either encircling fish and taking turns passing through to feed on the clustered fish or even driving fish onshore and temporarily stranding themselves to snatch up the fish. They typically eat 3.5 to 6 kg of krill, cuttlefish, squid, shrimp and small fishes per day. This is proportionally a much greater amount than either killer whales or bottlenose dolphins ingest each day, and is due to Commerson’s having a metabolic rate that is two to three times higher than many other whale or dolphin species.

 

Male Commerson’s dolphins mature between 5 and 8 years. South American females are believed to reach sexual maturity in about 5 to 8 years, female from the Kerguelen population at about 5 years. It is believed that adult female Commerson’s dolphins are in estrus or “heat” between late winter and early spring. Gestation lasts a maximum of about 12 months. The newborn calves are approximately 55 to 65 cm in length and weigh on average 4.5 to 5.5 kg. The calf makes up about 22 % of the mother’s body weight and is 61 % of her length on the average - in comparison a bottlenose dolphin calf composes only about 10 % of the mother’s weight and is about 46% her length. The total nursing period is unknown, but it is at least 4 or more months. The calves grow quickly reaching at one year of a ge a length of about 99 to 117 cm.

Did you know?
hat Commerson's dolphins are opportunistic, adapting its diet to the food items available in their habitat? They feed primarily near the bottom, on various species of fish, squid, and shrimp.


 

Factsheet
Class MAMMALIA
Order CETACEA
Suborder ODONTOCETI
Family DELPHINIDAE
Name (Scientific) Cephalorhynchus commersonii
Name (English) Commerson's dolphin
Name (French) Dauphin de Commerson
Name (German) Commerson-Delfin
Name (Spanish) Jacobita, DelfĂ­n de Commerson, Tunina overa
CITES Status Appendix II
CMS Status Appendix II (South American population only)

 

 

Photo Copyright by
Christian Bachmann

Distribution

 


Distribution
Range There are two disjunct populations of Commerson's dolphins; one located off the coast of southern South America and the Falkland Islands, and one found in the waters of the Kerguelen Islands in the Indian Ocean
Habitat Shallow coastal waters of the Subantarctic, along coastlines, bays, harbours, and river mouths, preferring water depths of less than 200 m.
Wild population Global populations are unknown, but recent surveys indicate that the species is still relatively abundant on the Patagonian shelf and in the Strait of Magellan (Red List IUCN 2011).
Zoo population Two reported to ISIS (2007). The first Commerson’s dolphin calf ever born in a marine zoological environment was born at SeaWorld San Diego on February 22, 1985. The calf weighed about 9 kg and measured 61 cm. Several more births have occurred since, giving scientists a rare firsthand knowledge about juvenile dolphins.

In the Zoo

Commerson's dolphin

 

How this animal should be transported

For air transport, Container Note 55 of the IATA Live Animals Regulations should be followed.

 

Find this animal on ZooLex

 

Photo Copyright by
Christian Schmidt

Why do zoos keep this animal

Cetacean Sensation—The Value of Whales and Dolphins at Zoological Parks

 

Marine life parks have learned a great deal about whales and dolphins from ongoing research programmes. In the protected environment of a marine life park, scientists can examine aspects of cetacean biology that are difficult or impossible to study in the wild. Breeding and cutting edge artificial insemination programmes have dramatically increased our understanding of cetacean reproduction. Such studies may one day help to conserve species facing extinction such as Amazon River dolphins.

 

But that’s only part of the story. Through educational programmes and guest visitation, millions of children and adults have been given the rare opportunity to experience whales and dolphins in a unique way. There is an old African saying that goes "You will love with your heart what you see with your eyes." Marine life parks educate millions of people every year on the threats whales and dolphins face. Through zoological facilities, visitors have a chance to see, touch and view whales and dolphins. This connection bonds humans to these animals and inspires stewardship far more than simply seeing them in a book or on TV.

 

Of course the jacobita is also an excellent ambassador for its ecosystem and may serve as a flagship species for awareness campaigns dealing with threats to the marine environment such as Deadline - Das Meer will leben !), a joint effort of YaquPacha and WAZA.