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Common Dolphin
Common Dolphins occur in warm temperate, subtropical and tropical waters
worldwide. Classification:The
Common Dolphin is named from the Latin and Greek words for dolphin,
referring to the fact that this was the species with which the Ancients
were most familiar. There are now two recognised forms: Delphinus
delphis, the short-beaked variety, and Delphinus capensis,
the long-beaked. Local Names:
Saddleback Dolphin; White-Bellied Porpoise; Criss-Cross Dolphin; Hourglass
Dolphin; Cape Dolphin.
Recognition
at sea: Common Dolphins can be identified
from the yellow-tan patch on either side, just behind each eye, and the
dorsal cape's 'V'-shaped dip. Habitat:
Common Dolphins prefer waters with a surface temperature that is higher
than 10ºC. Food &
Feeding: Common Dolphins prey on schooling
fish (e.g. herring, pilchards) and squid. They have been known to adopt
co-operative techniques when hunting (rather like the Orca) and have also
been observed catching fish in mid-air. Behavior: Highly social, Common Dolphins can be seen in groups of up to 2,000 animals, although units of 10-500 are more usual. Active and exuberate, they bowride, breach, somersault, flipper-slap and lobtail. When porpoising, they often cannot be seen for the froth they produce - they leap as a co-ordinated whole. Also highly vocal, their cries - whistles, pulses and clicks - can be heard above water as they play around vessels.
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Description:The
Common Dolphin is slender and streamlined, with a long or short beak,
depending on the geographical location. All forms vary slightly in size
but are recognisable as Common Dolphins due to the tell-tale 'hourglass'
pattern on each side. The dorsal cape is dark (brown, black, grey or
purplish), dipping to a distinct 'V' beneath the fin. The tail stock is
pale grey, darkening to black flukes. The underside is cream-white, and
extends higher up the sides than in most dolphins. It is broken by one or
two yellow or grey stripes that stretch from beak to beneath the
'V'-shaped dip. Another stripe - this one black - streaks from the dark
flippers to the middle of the lower jaw. Higher on the sides, behind the
eyes, is a yellow-tan patch which - together with the pale grey further
back - forms the criss-cross 'hourglass' pattern. A dark line circles the
eyes and leads to the grey-black beak, which can be white-tipped. In some
geographical forms, these colours can appear to be muted, or slightly
varied. There are 80-120 teeth per jaw. Common Dolphins range in size from
1.7m to 2.6m, and weigh between 70kg and 135kg.