Peale’s dolphin (Lagenorhynchus australis)

Description

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Peale’s dolphin fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Peale’s dolphin description

A fairly robust dolphin with a short, rounded snout, Peale’s dolphin is greyish black above and mostly white below. A curved, light grey flank patch runs from below or ahead of the dorsal fin to the tail, while a second light grey thoracic patch runs from the eye to the middle of the body. This second patch is separated from the white belly by a well-defined black line, which loops above a small white patch in the ‘armpit’, under the flipper ^{(2) (4) (5) (6)}. The flippers and dorsal fin are dark, and the dorsal fin is sickle-shaped, with a light grey trailing edge. The face, snout, melon and most of the chin are dark grey-black, which, together with the black line below the chest patch, readily distinguishes Peale’s dolphin from similar species such as the dusky dolphin (Lagenorhynchus obscurus). ^{(2) (4) (6)}. Young Peale’s dolphins are lighter grey than adults, with less clear definition between the chest and flank patches ^{(2) (4)}.

Also known as

Blackchin dolphin.

French

Dauphin De Peale, Lagénorhynque De Peale.

Spanish

Delfín Austral.

Size

Length: up to 2.2 m ⁽²⁾

Weight

ca. 115 kg ⁽²⁾

Peale’s dolphin biology

The biology of Peale’s dolphin is not well known, as it seldom strands, few specimens have been examined, and the species has not been kept in captivity ^{(2) (4) (6)}. Most feeding appears to occur in kelp beds ^{(4) (8)}, where small groups of around 5 to 30 individuals are thought to hunt squid, octopus, and sometimes shrimps ^{(2) (4) (6) (9)}. Larger groups have also been observed ^{(2) (4)}, and may hunt cooperatively in more open water, ‘herding’ larger shoals of fish ^{(4) (8)}. Peale’s dolphin is often seen associating with other dolphin species, particularly Commerson’s dolphin (Cephalorhynchus commersonii), and frequently bow-rides, producing loud splashes and slaps when leaping and swimming at the surface ^{(2) (4) (6)}.

Little information is available on reproduction in this species, but calves have been reported from spring to autumn (October to April) ^{(2) (4)}. In general, Lagenorhynchus species give birth to a single young after a gestation period of around 10 to 12 months, with the young measuring around one metre at birth ^{(2) (10)}. Migration in Peale’s dolphin is not well understood, but individuals around southern Tierra del Fuego appear to move inshore in the summer, possibly following fish migrations ^{(4) (11)}.

Peale’s dolphin range

Peale’s dolphin has a somewhat restricted range, being found only around the southern tip of South America, as far north as northern Argentina and Santiago, Chile. The species is commonly seen around the Falkland Islands (Malvinas) and over Burdwood Bank, south of the Falkland Islands ^{(2) (4) (6) (7)}. Possible sightings of Peale’s dolphins have also been reported from tropical waters, at Palmerston Atoll in the South Pacific, but this is considered to be outside the normal range and may even represent a new, undescribed species ^{(2) (4) (6)}.

Peale’s dolphin habitat

Peale’s dolphin occurs in open coastal waters over shallow continental shelves, as well as in bays, inlets, channels, around islands and in the openings to fjords ^{(1) (2) (4)}. Although recorded at depths of up to 300 metres, the species prefers shallower coastal waters ^{(1) (2)}, and appears to be particularly associated with kelp beds ^{(2) (4) (8)}.

Peale’s dolphin status

Classified as Data Deficient (DD) on the IUCN Red List ⁽¹⁾ and listed on Appendix II of CITES ⁽³⁾.

Peale’s dolphin threats

Although reported to be relatively common within its range, no population estimates are available for Peale’s dolphin ^{(1) (2) (7)}. There is also a lack of information on the impacts of the threats to the species, making it difficult to assess its conservation status ⁽¹⁾. Peale’s dolphin has been heavily exploited since the 1970s for use as crab bait, a practice which is thought to have reduced the species’ abundance by the late 1980s ^{(1) (2) (7)}. Although now banned, the practice still occurs in Chile, although at lower levels than before ^{(1) (4) (7)}. There is concern that the number of Peale’s dolphins taken could lead to problems for the species, especially given its restricted distribution ⁽⁶⁾.

Peale’s dolphin is also occasionally entangled and drowned in gillnets, and sometimes caught in anti-predator nets around salmon pens in Chile, although this is thought to occur only at low levels ^{(1) (2) (4) (7)}. Other potential threats to Peale’s dolphin include organochlorine pollution ⁽¹¹⁾, and any threats to the kelp forests on which the species depends ⁽⁸⁾. Tour operators have also recently begun offering trips to see Peale’s dolphins near Punta Arenas in Chile, but no laws exist to regulate this activity or to monitor its potential impacts ⁽⁷⁾.

Peale’s dolphin conservation

More information is needed on the extent of the exploitation of Peale’s dolphin for crab bait ^{(4) (7)}. The Chilean government has undertaken some measures to help regulate the use of marine mammals in crab fisheries, including educating fishing communities and providing alternative sources of bait, and the practice of using dolphins as bait is reported to have declined in recent years. However, a certain amount of illegal fishing and baiting may continue ⁽⁷⁾.

Other recommended conservation actions for Peale’s dolphin include further research into its biology and abundance, identification and protection of key habitats, education campaigns, and enforcement of hunting regulations ^{(1) (11)}. In addition to its listing on Appendix II of the Convention on International Trade in Endangered Species (CITES) ⁽³⁾, meaning international trade in Peale’s dolphin should be carefully controlled, the species is also listed on Appendix II of the Convention on Migratory Species (CMS) ⁽¹²⁾, based on the fact that its movement through the Beagle Channel and Strait of Magellan is likely to involve the national boundaries of Argentina and Chile ⁽¹¹⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

For more information on Peale's dolphin, visit:

• BBC Wildlife Finder:
  http://www.bbc.co.uk/nature/species/Peale%27s_Dolphin

To find out more about the conservation of this and other cetacean species see:

• Whale and Dolphin Conservation Society:
  http://www.wdcs.org/index2.php
• Reeves, R.R., Smith, B.D., Crespo, E.A. and Notarbartolo di Sciari, G. (2003) Dolphins, Whales and Porpoises: 2002-2010 Conservation Action Plan for the World’s Cetaceans. IUCN/SSC Cetacean Specialist Group, IUCN, Gland. Available at:
  http://data.iucn.org/dbtw-wpd/edocs/2003-009.pdf

Authentication

Authenticated (21/10/09) by William F. Perrin, Senior Scientist for Marine Mammals, National Marine Fisheries Service, Southwest Fisheries Science Center.
http://swfsc.noaa.gov

Glossary

Continental shelf

A region of relatively shallow water, not usually deeper than 200 metres, surrounding each of the continents.

Dorsal fin

The unpaired fin found on the back of the body of fish, or the raised structure on the back of most cetaceans.

Gestation

The state of being pregnant; the period from conception to birth.

Melon

A lump of fatty tissue that forms the bulging forehead of toothed cetaceans (whales, dolphins and porpoises), thought to focus sound during echolocation.

Thoracic

Of the thorax, or chest; the part of the body located between the head and the abdomen in animals. In insects, the three segments between the head and the abdomen, each of which has a pair of legs.

References

1. IUCN Red List (May, 2009)
   http://www.iucnredlist.org/
2. Jefferson, T.A., Webber, M.A. and Pitman, R.L. (2008) Marine Mammals of the World: A Comprehensive Guide to their Identification. Academic Press, London.
3. CITES (May, 2009)
   http://www.cites.org
4. Goodall, R.N.P. (2009) Peale’s dolphin Lagenorhynchus australis. In: Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (Eds) Encyclopedia of Marine Mammals. Academic Press, Amsterdam.
5. Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford.
6. Martin, A.R. (1990) Whales and Dolphins. Salamander Books, London.
7. Reeves, R.R., Smith, B.D., Crespo, E.A. and Notarbartolo di Sciari, G. (2003) Dolphins, Whales and Porpoises: 2002-2010 Conservation Action Plan for the World’s Cetaceans. IUCN/SSC Cetacean Specialist Group, IUCN, Gland. Available at:
   http://data.iucn.org/dbtw-wpd/edocs/2003-009.pdf
8. Viddi, F.A. and Lescrauwaet, A.K. (2005) Insights on habitat selection and behavioural patterns of Peale’s dolphins (Lagenorhynchus australis) in the Strait of Magellan, Southern Chile. Aquatic Mammals, 31(2): 176 - 183.
9. Iñíguez, M.A. and de Haro, J.C. (1994) Preliminary report on the feeding habits of the Peale’s dolphin (Lagenorhynchus australis) in southern Argentina. Aquatic Mammals, 21(1): 35 - 37.
10. Nowak, R.M. (1991) Walker’s Mammals of the World. The Johns Hopkins University Press, Baltimore and London.
11. Convention on Migratory Species: Lagenorhynchus australis (May, 2009)
    http://www.cms.int/reports/small_cetaceans/data/L_australis/L_australis.htm
12. Convention on Migratory Species (May, 2009)
    http://www.cms.int/