Range Description

The two disjunct subspecies are separated by 130° of longitude and about 8,500 km.

C. c. commersonii - Falkland Islands / Islas Malvinas and the coastal waters of southern South America. On the Atlantic coast the northern limit is at approximately Península Valdés. The range extends south into Drake Passage (61°50'S) as far as the South Shetland Islands, well within the range of C. eutropia (Rice 1998) (C. eutropia is predominately coastal and rarely goes into deep water or far offshore). Single dolphins and groups of up to hundreds were sighted in the late 1980s and early 1990s along the northern coast of Tierra del Fuego (Goodall 1994). Although sightings in the northern parts of the range often are of small groups or solitary individuals, overall numbers and group sizes increase to the south. On the west coast of South America, the northernmost confirmed record is a sighting of five individuals off Cape Valentin (53°33’S, 79°25’W) (Sielfeld and Venegas 1978). Genetic population structure is being studied in Argentina, where two “ecological stocks” have been identified based on differences in parasite loads and patterns of prey consumption (Berón-Vera et al. 2001).

C. c. subsp. nova - Shallow coastal waters around all of the Îles Kerguélen in the southern Indian Ocean (Rice 1998; Robineau et al. 2007). No sightings or specimens have yet been reported from islands between South America and Kerguélen, such as Crozet, Heard, Amsterdam or St Paul (Goodall 1994). Dolphins of the Kerguelen Islands subspecies are most commonly sighted in the Golfe du Morbihan, on the eastern side of Kerguélen.

Recently, a sighting of a single individual south of Cape Town, in South African waters, was reported, although this should be considered extralimital (de Bruyns et al. 2006). There are also unsubstantiated reports of this species at South Georgia, but these have been rejected (Brown 1988).