The Gray Whale was once very numer us; population estimates placed their numbers at being between 25,000 to 30,000 whales. Whalers hunted them extensively, and due to their slow traveling speed and well-known migratory route they were easily found in numbers. The discovery of their breeding lagoons in Mexico further hastened their decline. At one time there were 15 on-land stations in California alone for the processing of Gray Whales. Each whale yielded 25 to 45 barrels of oil, which sold for $27 to $40 a barrel in 1855. Whale oil was very important at that time for use in lamps and in lubricating machinery.
When Gray Whale stocks near shore were depleted, hunting pressure let up on them for a bit; but the development of steam and diesel "factory ships, " which could catch, process and store the whale products all on board, renewed the slaughter. In 1946 the International Whaling Commission (a "self-regulating" body comprised of members of nations that have or had whaling industries) afforded protection to the Gray Whale, since it was obviously endangered. Since then it has come under the further protection of the Marine Mammal Act, the Endangered Species Act, and other federal and international protection treaties. The whale numbers have now rebounded to an estimated 21,000+. They are still exempt from hunting, with the exception of the allowed "take" of 180 whales per year by natives of Siberia and Alaska who have traditionally used them as a source of food and materials.
Gray whales mate one year and give birth the next. Calves are usually born in the warm, shallow lagoons of Baja California, between December and April. Calves average 15 feet long at birth and weigh an estimated 1500 pounds. Nourished by approximately 50 gallons of the mother's rich milk each day, calves may gain 60 to 70 pounds daily and reach 18 to 19 feet in length by the end of winter. By mid- February, newly-pregnant females leave the lagoons to begin the northward migration. They are soon followed by the males, who continue courtship, and by juveniles of previous years. Mothers and new calves are the last to leave, occasionally remaining as late as May or June. (NOTE: There is evidence to suggest that some whales are not making the full migration, staying for long periods or even year-round at some localities along the coast. Whether this is due to the increase in numbers, or has always been true, is not known.)
Gray Whales reach sexual maturity at six to eight years of age. They are thought to live 30 to 40, and occasionally to 60 years.
Unique among whales, Gray Whales are bottom feeders, the bulk of their diet appears to be bottom- dwelling crustaceans called amphipods, which are quite abundant in the cold waters of the west coast of North America. The whale dives to the bottom, rolls to one side (usually the right side, though there are some "left-sided" whales), and suck up huge quantities of bottom sediment and water. This is pushed back out of its mouth and through the baleen with the gigantic tongue, screening out the edible matter. Whales put on most of their blubber in the summer time. It is thought that they eat very little, if at all, during the migration; however, evidence shows that some may do limited feeding, and mothers with calves have been seen "mouthing" giant kelp during their return trip. Also, it is likely that the whales take advantage of occasional "blooms" of creatures, such as occurs during the "El Nino" periods of local oceanic warming.
Aside from man, the Gray Whale's only "enemies" are probably large, predatory sharks and Killer Whales. Killer whales packs have been known to hang onto the flippers and flukes of large whales, even Blue Whales, until the giant is tired out and succumbs to the attack.
Gray Whales are also infested with parasites," animals that live on or in the body of the whale". The two major external parasites are whale barnacles, which imbed themselves in the whale's skin, especially around the head, back and tail; and cyamid crustaceans called "whale lice" which cluster about the barnacles and in t e folds and slits of skin. They are thought to eat dead skin cells as they slough off the whale, while barnacles are filter- feeders that stain microscopic food from surrounding water. Thus, these particular creatures probably do not harm the whale, although they may be irritating. A large Gray Whale may carry 100 pounds of barnacles!
Whale lice are host- specific, meaning that any given species of whale louse will be found on only one kind of whale; the Gray Whale has three known species of whale lice that live on it.
Whale lice emerge from a "brood pouch" on their parent as miniature adults, and immediately dig in with sharp, hooked dactyls to prevent being swept away. Since they lack the free-swimming stage of many crustaceans, their transfer from whale to whale is thought to occur at those times when the whales come into contact with one another: mating, fighting, playing, feeding, nursing and migrating.
Although generally docile by nature, Gray Whales can be dangerous because of their size and str ngth, and their timidity. They often do not like to be approached by divers in the water, though they will sometimes come alongside boats, and have even been known to allow petting by people in small rafts. However, they are highly protective of each other, especially of their young, and if they sense danger they can be formidable. This earned them the nickname "devilfish" by early whalers.
Whales are first generally located by their "spout" or "blow. " In the Gray Whale, this is low and spreading, although it may reach heights of 15 feet and appear heart-shaped from the front or back. It can be seen for miles in ideal weather, and heard for a half mile or so. The spout is mostly condensation created as the whale's warm breath expands and cools in the sea air, as well as sea water carried with it if the forced exhalation begins just before breaking the surface. Generally, there will be three to five blows, 30 to 50 seconds apart, followed by a deeper dive of four or five minutes duration (as a "rule of thumb, "a Gray Whale will blow once for each minute it has been down).
Some other behaviors have been noted among Gray (and other) Whales that should be mentioned- One is caged Spyhopping. Some scientists believe that Gray Whales can see as well in the air as they can in water. Occasionally a Gray Whale will be seen extending its head vertically from the sea, 8 to 10 feet above the surface, sometimes turning slowly. 'They support themselves in this position by thrusting their flukes ("treading water"), or resting their tail on the bottom in shallow water. Are they taking their bearings? Looking for landmarks or obstructions? Just taking a casual glance around?
Many whales breach, which is when 1/2 to 3/4 or more of the whale's body suddenly bursts from beneath the surface, often twists to one side or upside- down, and re-enters the water with a terrific splash. Is this courtship? An effort to dislodge some irritating parasites? An expression of stress? Or is it done in play, just for fun? Gray Whales ave been seen to breach two or three times in succession, and continue for a dozen or more displays.
Following a series of short surface dives, Gray Whales normally descend for a single, longer, deep dive. Just before such a dive, the dorsal ridge and knuckles will be readily visible, and the flukes will usually appear above the surface as they thrust the whale's bulk downward. This (when the flukes appear) is called sounding. The flukes at this time may be seen to bear scars of encounters with rocks, barnacles, sharks or Killer Whales. The pattern of such scars is unique to each individual whale, and some cetacean study groups are amassing photo libraries of whale tails for use in identifying certain whales year after year.
Migrating whales travel about 20 to 100 miles a day, at a leisurely rate of 6 to 10 knots (6.9 to 11.5 mph). They sleep at the surface, with blowholes exposed...