White Beaked
Dolphin
Lagenorhynchus albirostris
Key Facts
Size: Up to 3.1metres, female smaller
Range: Cool waters of North Atlantic and North Sea
Threats: Caught in trawling nets, pollution, caught by ice
Diet: Bottom-dwelling fish such as cod and whiting, and squid
Physical description
The white-beaked dolphin grows up to 3.1
meters and is sturdy and plump-looking. The body is mostly black or grey
with a pale saddle behind the dorsal fin and white bands on the flanks.
The belly is white and although called the white-beaked dolphin the beak
is sometimes grey or even darker. The dorsal fin is prominent and falcate
and is placed mid-way down the body. The pectoral fins are short and wide
and it has a prominently keeled peduncle (the area between the dorsal fin
and the tail). |
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Distribution
This species is endemic to the temperate and sub-arctic waters
of the North Atlantic as far north as the White Sea and occasionally as
far south as the Spanish coast. It is common off the Norwegian coast and
in the North Sea and is often found in the Baltic Sea as well. Less are
found in the northwest Atlantic but there are abundant populations off
Labrador and they are found as far south as Cape Cod.
Behavior
White-beaked dolphins are typically seen in groups of 5 to 50
and occasionally in schools of several hundred. They are attracted by
boats and often bow ride. They are very acrobatic and have a distinctive
“rooster tail splash” when swimming fast. White-beaked dolphins are often
seen in mixed groups with white-sided dolphins and they also associate
with feeding fin whales and humpback whales. They are not well-adapted to
ice formation and often get trapped in groups by new ice.
Breeding
The age of sexual maturity for the white-beaked dolphin is not
known but the females seem to become mature when they grow to 2.4 meters
and males to 2.5 meters. Mating takes place in the summer between June and
September and gestation is about 10 to 11 months so that calving occurs in
the early summer.
Feeding
In eastern Canada the white-beaked dolphins are sometimes known
as “squid-hounds”, but they also eat a wide range of fish, ranging from
small schooling fish such as common herring to larger bottom-dwelling fish
such as cod, whiting and haddock. They are also known to eat mollusks,
octopus and some crustaceans.
Current situation
Although not commercially hunted, these dolphins are killed by
hunters and fishermen in Newfoundland, Labrador, Greenland and the Faeroe
Islands. The white-beaked dolphin is found abundantly in patches so it is
difficult to estimate the overall population but it is thought that there
may be a few hundred thousand individuals. There has been a marked
decrease in populations in the northwest Atlantic but an increase in the
populations off Europe. |
