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GRAY WHALE
Eschrichtius robustus
(Lilljeborg, 1861)
DERIVATION: Eschricht refers to a 19th Century Danish zoology
professor; from the Latin robustus for oaken or strong.
The gray whale is best known for its annual migration north and south
along the coast of western North America. This 10,000-14,000 mile round
trip is among the longest known of any mammal, and, in many instances,
brings the whales within viewing distance from land.
New claim states humpback whales may make the longest migration. – click here to learn more –
Their journey begins in fall when temperatures begin to drop in the circumpolar
seas surrounding Siberia and Alaska. The gray whales have spent May through
November feeding in the food-rich Bering, Chuckchi and western Beaufort
seas. Their lengthy migration will take them to the temperate waters of
Baja, California, where mating occurs and calves are usually born.
Yankee whalers discovered the Baja lagoons in the 1850s and their slaughter
of gray whales brought the population to commercial extinction in just
18 years. Whalemen would harpoon calves in order to get their mothers
within range. The beleaguered mothers would aggressively defend their
calves by ramming and smashing boats. They would "fight like devils"
and hence were named "devilfish."
After the turn of the century, gray whales were again decimated when floating
factories (which process whales) were introduced. In 1946, by international
agreement, gray whales were given protection from commercial whaling and
their population has grown to its current estimate of 21,000. This is
believed to be close to its pre-exploitation stock size. It is the only
baleen whale to have recovered from commercial whaling.
In addition to its marathon migration, the gray whale has other unusual
characteristics. It is considered the most primitive whale, or the one
most like the common ancestor of all whales. It is the sole representative
of the family Eschrichtiidae and the only whale to range in the comparatively
shallow waters of the continental shelves.
Gray whales are baleen whales. Baleen is a giant filter-feeding device
and consists of fringed plates which overlap and hang from the upper jaw
(130-180 on each side). The plates consist of a material called keratin
which is the same substance found in human fingernails.
Close-up of Gray Whale baleen
Unlike other baleen whales, gray whales usually feed on the ocean bottom.
They scoop mouthfuls of bottom sediment and, after filtering it through
their baleen, retain the living organisms. This feeding technique is also
considered primitive.
Physical Characteristics:
The gray whale is about 17 feet long at birth and reaches a maximum size
of approximately 45 feet; females are larger than males. It has no dorsal
fin, but a series of from six to twelve knuckle-like knobs along the dorsal
ridge. Its color is mottled gray, sometimes with patches that are very
pale or white. A distinctive feature is their barnacle clusters, which
are usually on their head and back. Whale lice are orange-colored crustaceans
that inhabit the same areas and folds and grooves, as well as the open
surface of the skin. The top of their tapering jaw has pits or depressions,
each containing one stiff hair. Life expectancy is about 50 years.
Barnacles on Gray whale |
Mother and newborn calf
|
Sexual Maturity:
11.1m, males; 11.7m, females and occurs between five and eleven years
of age. Females bear a single calf at intervals of two or more years.
Calves appear to be weaned in nine months, in time for the fall migration.
Diet: amphipod crustaceans, polychaete worms, crab larvae, small fish, crabs
and possibly plants and seaweed.
Enemies: killer whales (Orcinus orca) may be a significant cause of
gray whale deaths, particularly of young migrating whales. There are numerous
reports of killer whales feeding on tongues of gray whales and leaving
the carcasses. Scars from killer whale teeth are often observed on gray
whales. Large sharks in the calving lagoons may be responsible for some
calf death.
A major concern along the west coast is the increasing entanglement of
gray whales in fishing gear and nets. In the Southern California area,
the number of gray whales seen migrating along the coast has dropped.
It could be attributed to a variety of factors, but the aggressive tactics
of recreational boaters is believed to harass the whales. Gray whales
were removed from the Endangered Species list in early 1993 and are now
a "protected" species. Save The Whales was opposed to their
delisting for several reasons: it could diminish protection from noise
pollution (caused by drilling or boat traffic); it could increase the
possibility of oil exploration in their migration routes; and because
of potential dangers from lack of genetic diversity and absence of genetic
studies. Furthermore the effects of chemical pollution on future generations
pose very serious questions that lack answers.
A threat now comes from the Makah Indian tribe of northwestern Washington
and their efforts to resume hunting of the grays.
By: Maris Sidenstecker
Protect the Gray Whales in Magdalena Bay, Mexico
1 October 2009
Save The Whales has received complaints from US citizens who have traveled to Magdalena Bay in Baja, Mexico, for a relaxing whale watching vacation and leave horrified as to the lack of concern for safety of the whales. Boats will completely surround the whales and have even been seen running over them.
If you have had this experience, you can voice your concern and ask the Mexican government to correct this situation and to provide needed protection for the gray whales. Many of them are mothers with new-born calves.
Send an email to:
Deputy Minister Mauricio Lim
Subsecretario de Gesti la Protecci Ambiental
mauricio.limon@semarnat.gob.mx
The agency in charge of environmental protection is:
SEMARNAT (www.semarnat.gob.mx)
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