The Mammals of Texas -
Online Edition
Northern Right Whale
Order
Cetacea : Family Balaenidae : Eubalaena
glacialis Borowski
Description. 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.
Distribution in Texas. Worldwide
in distribution but extremely rare. Only 3,000-4,000
remain in the worlds 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.
Habits. 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
worlds 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.
Illustration credit: Pieter
A. Folkens.
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