Delphinus delphis

Description: 

The short-beaked common dolphin is one of three species in the Genus Delphinus (in addition to D. capensis or the long-beaked common dolphin and the endemic D. tropicalis in the Indian Ocean).

Short-beaked common dolphin © M. Camm

 

Physical Description & Behaviour

The species has a characteristic slender body shape combined with a relatively long beak, which is sharply separated from their forehead. Their colour pattern usually involves a dark back and white underbelly, and an hourglass pattern coloured light grey and yellow on each side of their body.

Adult common dolphins can reach up to 2.7 metres in length and 135 kg. As very social animals, they are usually found in groups of 10-15 animals, which often join up to form schools of several hundred to several thousand individuals.

They are fast swimmers and sometimes approach moving vessels to bow-ride. Aerial behaviour typical of them includes “pitch polling” where dolphins leap high vertically and fall lengthwise back into the water.

Common dolphins feed on various small mid-water fish and squid. Their diet varies with the season as well as by region.

 

Distribution & Abundance

Common dolphins are typical oceanic dolphins and live in the tropical to warm temperate zone. They are often associated with schools of other whales and dolphins, such as pilot whales for example.

In the ASCOBANS area they are normally restricted to the southwest of the British Isles and the English Channel. According to the SCANS II Project, about 75,000 individuals inhabit this region.

IUCN Red List of Threatened Species™ Assessment

  • ASCOBANS Area: LC (least concern)

 

Threats

Common dolphins die in large numbers in purse seine fisheries in the eastern tropical Pacific and in gillnet fisheries around the world. In the Celtic Sea and Bay of Biscay, it suffers incidental capture in fishing gear from multi-national pelagic trawl and drift net fisheries. In addition to bycatch, they are increasingly threatened by marine pollution, underwater noise and habitat loss.

 

More information on the common dolphin can be found at
http://www.cms.int/reports/small_cetaceans/data/d_delphis/d_delphis.htm.

 

 

Assessment information
CMS InstrumentsASCOBANS, CMS, ACCOBAMS, Pacific Islands Cetaceans, Western African Aquatic Mammals
IUCN StatusEndangered
Date of entry in Appendix I2005
Date of entry in Appendix II1988
Geographic range
Countries Denmark (Status: Increase), France (Status: Increase), Ireland (Status: Unknown), Norway (Status: Increase), Portugal (Status: Unknown), Spain (Status: Unknown), United Kingdom (Status: Unknown)
Common names
EnglishShort-Beaked Common Dolphin
Taxonomy
ClassMammalia
OrderCetacea
FamilyDelphinidae
Scientific name Delphinus delphis
Population per instrument
Instrument Population name
Population size and trend
Population Size interval Size quality Estimated population size Size reference Size notes
Trend interval Trend quality Trend Trend reference Trend notes
Northern East AtlanticFair75,449 Project Report: Review of Trend Analyses in the AS [more] The population size estimate is based on data collected during SCANS-II (2005) and CODA (2007) surveys. See the previous Trend Analysis document for more details. SCAN-II and CODA reports can be found in the additional notes section. Common dolphin abundance was concentrated off the coast of Ireland, in the Celtic Sea and western Channel, and the coasts of Spain and Portugal.
NoneIncrease - uncertain Project Report: Review of Trend Analyses in the AS [more]
Central East AtlanticFair167,216 (SCANS-II = 50,507, CODA = 116,709)* Project Report: Review of Trend Analyses in the AS [more] The population size estimate is based on data collected during SCANS-II (2005) and CODA (2007) surveys. See the previous Trend Analysis document for more details. SCAN-II and CODA reports can be found in the additional notes section. Common dolphin abundance was concentrated off the coast of Ireland, in the Celtic Sea and western Channel, and the coasts of Spain and Portugal. *Note: the estimated population size is for the whole survey area and not just for the Central East Atlantic. The separate estimate for this region is not available.
NoneIncrease - uncertain Project Report: Review of Trend Analyses in the AS [more]
Bay of BiscayFair167,216 (SCANS-II = 50,507, CODA = 116,709)* Project Report: Review of Trend Analyses in the AS [more] The population size estimate is based on data collected during SCANS-II (2005) and CODA (2007) surveys. See the previous Trend Analysis document for more details. SCAN-II and CODA reports can be found in the additional notes section. Common dolphin abundance was concentrated off the coast of Ireland, in the Celtic Sea and western Channel, and the coasts of Spain and Portugal. *Note: the estimated population size is for the whole survey area and not just for the Bay of Biscay. The separate estimate for this region is not available.
NoneIncrease - uncertain Project Report: Review of Trend Analyses in the AS [more]
Northern North SeaFair167,216 (SCANS-II = 50,507, CODA = 116,709)* Project Report: Review of Trend Analyses in the AS [more] The population size estimate is based on data collected during SCANS-II (2005) and CODA (2007) surveys. See the previous Trend Analysis document for more details. SCAN-II and CODA reports can be found in the additional notes section. Common dolphin abundance was concentrated off the coast of Ireland, in the Celtic Sea and western Channel, and the coasts of Spain and Portugal. *Note: the estimated population size is for the whole survey area and not just for the Northern North Sea. The separate estimate for this region is not available.
NoneIncrease Project Report: Review of Trend Analyses in the AS [more]
Inner Danish WatersFair167,216 (SCANS-II = 50,507, CODA = 116,709)* Project Report: Review of Trend Analyses in the AS [more] The population size estimate is based on data collected during SCANS-II (2005) and CODA (2007) surveys. See the previous Trend Analysis document for more details. SCAN-II and CODA reports can be found in the additional notes section. Common dolphin abundance was concentrated off the coast of Ireland, in the Celtic Sea and western Channel, and the coasts of Spain and Portugal. *Note: the estimated population size is for the whole survey area and not just for the Inner Danish Waters. The separate estimate for this region is not available.
NoneIncrease - uncertain Project Report: Review of Trend Analyses in the AS [more]
Baltic SeaFair167,216 (SCANS-II = 50,507, CODA = 116,709)* Project Report: Review of Trend Analyses in the AS [more] The population size estimate is based on data collected during SCANS-II (2005) and CODA (2007) surveys. See the previous Trend Analysis document for more details. SCAN-II and CODA reports can be found in the additional notes section. Common dolphin abundance was concentrated off the coast of Ireland, in the Celtic Sea and western Channel, and the coasts of Spain and Portugal. *Note: the estimated population size is for the whole survey area and not just for the Central East Atlantic. The separate estimate for this region is not available.
NoneIncrease - uncertain Project Report: Review of Trend Analyses in the AS [more]
English ChannelFair14,300 Project Report: Review of Trend Analyses in the AS [more] The population size estimate is based on data collected during SCANS-II (2005) and CODA (2007) surveys. See the previous Trend Analysis document for more details. SCAN-II and CODA reports can be found in the additional notes section. Common dolphin abundance was concentrated off the coast of Ireland, in the Celtic Sea and western Channel, and the coasts of Spain and Portugal.
NoneUnkown Project Report: Review of Trend Analyses in the AS [more]
Irish SeaFair167,216 (SCANS-II = 50,507, CODA = 116,709)* Project Report: Review of Trend Analyses in the AS [more] The population size estimate is based on data collected during SCANS-II (2005) and CODA (2007) surveys. See the previous Trend Analysis document for more details. SCAN-II and CODA reports can be found in the additional notes section. Common dolphin abundance was concentrated off the coast of Ireland, in the Celtic Sea and western Channel, and the coasts of Spain and Portugal. *Note: the estimated population size is for the whole survey area and not just for the Irish Sea. The separate estimate for this region is not available.
NoneUnkown Project Report: Review of Trend Analyses in the AS [more]
Other details
Additional notesA SCANS-II report can be found here: http://biology.st-andrews.ac.uk/scans2/inner-furtherInfo.html and here http://biology.st-andrews.ac.uk/scans2/documents/final/SCANS-II_final_report.pdf. A CODA report can be found here: ttp://biology.st-andrews.ac.uk/coda/documents/CODA_Final_Report_11-2-09.pdf. The notes in the Threat section (Related Content) refer to the level of importance needed to address causes of mortality (identified from post-mortem examinations) of cetaceans in the ASCOBANS Agreement Area. This information also comes from this report: Project Report: Review of Trend Analyses in the ASCOBANS Area (AC18_6-05_ProjectReportTrendAnalysis_Corr.pdf).

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