Eubalaena glacialis Borowski
A large, blackish whale with the following features: no dorsal
fin; head huge, about one-fourth of total length; baleen (whalebone)
about 2 m long, 30 cm wide, and between 200 and 250 in number
on each side of mouth; closure of mouth highly arched; no
furrows on the throat; prominent, large, wartlike areas (called
bonnets), the one near tip of snout largest. Total length
of adults, 14-17 m; weight, 20-30 metric tons.
Worldwide in distribution but extremely rare. Only 3,000-4,000
remain in the world’s oceans, with about 100 constituting
the North Atlantic population. These whales are listed as
"endangered." Known in Texas from a single individual
that beached in February, 1972, at Surfside Beach near Freeport,
Brazoria County.
Right whales were so named by early whalers because they were
the "right" whale to kill — they are slow
swimmers and were thus easily caught, floated when dead, and
produced large quantities of oil and baleen. Consequently,
right whales were decimated early by the world’s whaling
industries and have yet to recover.
Right whales spend spring, summer, and autumn at high latitude
feeding grounds and migrate to more southerly, warmer waters
in winter for mating and calving. Northern and southern populations
do not interbreed due to asynchronous seasons between the
hemispheres.
Right whales produce a variety of vocal sounds as well as
percussive sounds of breaching, flipper slapping, and tail
slapping. A distinctive clacking sound has been described
for these whales as they feed at the surface. Termed the "baleen
rattle," this sound is produced by small wavelets rattling
the baleen plates when they are partially held out of water.
Right whale sounds appear to differ with changing behavior
and, thus, may be important in communication. As with other
baleen whales, right whales probably do not echolocate.
Right whales feed by skimming through concentrations of krill.
They have been seen feeding at depths ranging from the surface
down to 10 m although they may also feed at deeper levels.
Location of krill concentrations in the water column probably
determines feeding depth.
After a one-year gestation period, females give birth to
a single calf in winter. Calves are 5-6 m in length at birth
but grow rapidly during the subsequent period of lactation,
which lasts about 13 months. Calves remain with their mothers
for 2-3 years following weaning and probably reach sexual
maturity at about 10 years of age. Females give birth at 2
to 7 year intervals.
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