The right whales are marine mammals belonging to the family Balaenidae. There are four species in two genus - Eubalaena - three species of right whale (which are discussed below), and Balaena - the Bowhead Whale.
Taxonomy:
The taxonomy of the right whales has long been controversial. The Bowhead
Whale is clearly an individual species and has always been recognised as such.
However, different authorities have disagreed over whether to categorise the
other right whales as a single worldwide species, as two species (one found
only in the northern hemisphere, the other found in the Southern Ocean), or
as three species (splitting the northern species into Pacific and Atlantic
populations). Small differences in the skull shape of northern and southern
animals have tended to lend support to the two-species view. No group of right
whales has been known to swim through warm equatorial waters to make contact
with the other (sub)species and (inter)breed.
In recent years, genetic studies have provided clear evidence that the northern and southern populations have not interbred for between 3 million and 12 million years, confirming the status of the Southern Right Whale as a distinct species. More surprising has been the finding that the northern hemisphere Pacific and Atlantic populations are also distinct, and that the Pacific species (now known as the Pacific Northern Right Whale), is in fact more closely allied with the Southern Right Whale than with the Atlantic Northern Right Whale.
ORDER CETACEA
Suborder Mysticeti
Family Eschrichtiidae: Gray Whale
Family Balaenopteridae: Rorquals
Family Balaenidae
Atlantic Northern Right Whale, Eubalaena glacialis
Pacific Northern Right Whale, Eubalaena japonica
Southern Right Whale, Eubalaena australia
Bowhead Whale, Balaena mysticetus
Family Neobalaenidae: Pygmy Right Whale
Suborder Odontoceti: 9 families.
Other names:
Due to their familiarity to whalers over a number of centuries the right whales
have been given many names over the years. They reflect the fact that it is
only in recent times that two species have been distinguished. In his novel
Moby Dick, Herman Melville writes: "Among the fishermen, [the whale regularly
hunted for oil] is indiscriminately designated by all the following titles:
The Whale; the Greenland Whale; the Black Whale; the Great Whale; the True
Whale; the Right Whale."
Physical description:
Right whales are easily distinguished from other whales by the large number
of callosities on their heads, a thick back without a dorsal fin, and a long
dropping mouth that begins high above the eye and the arches round beneath
it. The body of the whale is very dark grey or black with some white patches,
particularly on the belly. Right whales are slow swimmers but highly acrobatic
and frequently breach (jump clear of the sea surface), tail-slap and lobtail.
Females reach sexual maturity at 6-12 years and breed every 3-5 years. Calves
are approximately 1 tonne in weight and 2-4 metres in length. Adults may be
between 11-18 metres in length and up to 80 tonnes in weight. Right whales
have between 250 and 350 baleen plates on each side of the mouth.
Whaling:
Right whales were named because whalers thought they were the 'right' whale
to hunt, for several reasons. Most importantly, 40% of a right whale's body
weight is blubber (which is of relatively low density). In consequence, unlike
other whales, right whales float when they die, which made them easy to catch,
even for men equipped only with frail wooden boats and hand-held harpoons.
Hunting of right whales began as early as the 11th century in the Bay of Biscay,
and continued throughout the centuries until the Atlantic population was commercially
extinct. Exploitation of the Pacific and Southern Right Whales followed, and
they too were on the brink of extinction by the early 1900s. A worldwide total
ban on right whaling was agreed in 1937.
Population and distribution:
There are about 300 Atlantic Northern Right Whales, almost all living in the
west North Atlantic, feeding in areas off the Canadian and US coasts. Sightings
as far east as Iceland have been reported in 2003. A small population probably
exists in the north Pacific. The Northern Right Whales are the most endangered
of all large whales and two of the most endangered animals in the world. Based
on current population density trends the species is predicted to become extinct
within 200 years ([1] (http://news.bbc.co.uk/1/hi/sci/tech/3256406.stm)).
Southern Rights spend the summer months in the Southern Ocean feeding, probably
close to Antarctica. Animals migrate north in winter for breeding and can
be seen around the coasts of Chile, Argentina, South Africa, Australia and
New Zealand. The total population is estimated to be 6-7,000. Since hunting
of the Southern Right Whale ceased, stocks have estimated to have grown by
only 7% in 60 years. However the IUCN lists the species as lower risk; conservation
dependent in their Red List of Threatened Species.
Hearing:
A report published in the Proceedings of the Royal Society B in December 2003
suggested that Northern Rights responded rapidly on hearing sounds similar
to police sirens. On hearing the sounds they moved rapidly to the surface.
The research was of particular interest because it is known that Northern
Rights ignore most sounds, including those of approaching boats.
Whale watching:
Southern Right Whales have made Hermanus, South Africa one of the world centres
for whale watching. During the winter months (July-October) Southern Right
Whales come so close to the Cape shoreline that visitors can watch whales
from their (deliberately placed) hotels. The town employs a 'whale crier'
(c.f. town crier) to walk through the town announcing where whales have been
seen. Southern Rights can also be watched at other winter breeding grounds.
Conservation:
The particular vulnerabilility of the Northern Right Whale, which migrates
through some of the world's busiest shipping lanes whilst journeying off the
east coast of the United States, to collisions with ships led the National
Oceanic and Atmospheric Administration to propose new guidelines for captains
of vessels in the area in June 2004. The guidelines, currently open to public
consultation, proposed a raft of measures restricting where ships could travel,
and at what speed they can move in common right whale feeding areas.
References:
Encyclopedia of Marine Mammals, editors Perrin, Wursig and Thewissen.
Collins Gem : Whales and Dolphins.
Whales, Dolphins and Porpoises, Mark Carwardine.