Whales, Whales, Whales
The Eschrichtiidae Family - Mysticeti
Baleen WhalesA moderately robust large whale with many encrustations over its back, many short baleen plates, jaws relatively short and broad, rostrum (upper jaw) narrow and gently arched, two short throat groves, no dorsal fin.
The Gray Whale
(Eschrichtius robustus)
The Gray Whale is one of the most active of all large whales with spyhopping, lobtailing and breaching commonly observed. The Gray can grow to a length and weight of 15m (50ft) 30-35 tonnes for the female and 14m (46ft) 16 tonnes for the male. This whale is well known for the 19,500km (12,000 mile) round trip between its northern feeding grounds in the Beaufort, Bering and Chukchi seas and its southern breeding grounds in Baja California and off the Korean coast.
The Gray whale is mottled grey over it's entire body including the flippers and tail flukes (though albino individuals are not uncommon). This grey body is covered with white, yellow or orange patches of barnacles and associated parasites (whale lice), particularly on top of the head, around the blowhole and on the anterior part of the back. The head is narrow and arched along the upper surface giving it a conical shape. It's mouth contains small hairs along the upper jaw with 130-180 relatively small baleen plates on each side.
Primarily a bottom feeder, the Gray will dive to 120m (395ft) deep, but prefers much shallower water. While feeding it stirs up clouds of mud from the seabed and from it's mouth during filtration. During this time the whale will mostly consume tubeworms and sessile polychaetes. While migrating the Gray will feed at the surface on small fish and shrimp-like mysids (Acanthomysis sculpta) but once the Arctic is reached it will consume it's main prey gammarid amphipods.
Subfamily Eschrichtidae.
Other Names: California Gray Whale, Devilfish, Mussel-digger, Scrag Whale.
Three populations once existed. One in the North Atlantic was hunted to extinction around 1700; a Korean population in the Northwest Pacific was hunted until 1968 and is now rare; the third, a Californian population in the Northeast Pacific still exists in moderate numbers, 17,000 - 18,000 despite earlier overexploitation.
The Gray whale can be observed in December to April in Mexico, with small numbers in British Columbia, Canada, Washington State, Oregon,and northern California. The main breeding lagoons in Mexico are Ojo de Liebre, Guerrero Negro, San Ignacio, Scammon's and the Magdalena Bay complex.
During April to November the whales inhabit their Arctic feeding grounds in the northern Bering Sea and southern Chukchi Sea.
The Balaenidae Family - Mysticeti
Baleen WhalesThe baleen apparatus is at its most extravagant in this species. The head is huge, in some species up to 40 per cent of body length. All seven neck vertabrae are fixed into a single unit to support the enormous body weight.
The Minke Whale
(Balaenoptera acutorostrata)
The Minke whale is the smallest of the rorquals. The male of the species can grow to a length of 9.8m (32ft) and the female larger at 11m (36ft) and weigh 10 tonnes. Populations in the Southern hemisphere on the average are slightly larger than other areas. Some animals are inquisitive and approach quite closely, but in most cases it is unusual to get a clear view. The Minke can be confused with the Sei, Bryde's, Fin or Northern Bottlenose whale, however, the dive sequence is distinctively different, the head is unscarred and it's mouthline is relatively straight.
The Minke whale has a slender streamlined body with a pointed head and often inconspicuous blow. The body is dark grey to black on the back, lightening to white on the belly and undersides of the flippers. There are often areas of light grey on the flanks, one just above and behind the flippers and the other behind the head. Individuals in the Northern hemisphere have a diagonal white band on the upper surface of each flipper. The head of the whale has an overall triangular shape, a single sharp longitudinal ridge along the top and forward of the blowhole and a narrow pointed snout. It has twin blowholes typical of all baleen whales.
Baleen plates are found on each side of the upper jaw. The plates numbering between 230 to 360 are short 20-30cm (8-12in) in length and about 12cm (5in) in width. The colour of the plates vary from region to region; in the North Atlantic, it tends to be creamy white; in the North Pacific, it is usually creamy yellow; and in the Southern hemisphere it is creamy white at the front and dark grey at the back. Atlantic Minkes usually have more plates than the Pacific Minkes.
Subfamily Balaenopterinae.
Other Names: Lesser Rorqual, Lesser Finback, Little Finner, Sharp-headed Finner, Pike whale, Little Piked whale, Pikehead.
Minke whales can be found virtually worldwide, but are less common in the tropics than in cooler waters. The Minke often enters estuaries, bays and inlets and during summer may feed around headlands and small islands. Most, seasonally migrating from polar feeding grounds to warm temperate to tropical breeding grounds although there appears to be some groups resident year-round. There are three geographically isolated populations recognized, in the North Pacific, in the North Atlantic and in the Southern Hemisphere.
The Minke is the smallest of the seven great whales. It's size made it uneconomical to harvest commercially while the larger whales were in abundance. The species became protected with the declaration of the 'Moratorium' on whaling by the International Whaling Commission in 1986. Norway and Japan are two countries that argue since the Minke is abundant it is not endangered and therefore they are harvesting (killing), albeit in small numbers, this species on a regular basis. Although it's numbers are not endangered it is on the endangered list as a threatened species, and is protected (since 1986) worldwide by international law.
The Delphinidae Family
Blackfish or Smaller Toothed WhaleAlthough generally considered more closely related to dolphins than other whale species, the word 'whale' is used broadly to indicate size rather than zoological affinity. They are unlike dolphins in appearance and do not migrate but move around according to the availability of food and natural conditions such as depth of water.
The (Orca) Killer Whale
(Orcinus orca)
The Killer whale is the largest member of the dolphin family. This distinctive jet-black, brilliant white and grey marked, huge dorsal finned male, makes this animal relatively easy to identify. The female and juvenile, at a distance however, can be confused with Risso's dolphin, the False Killer whale and even Dall's Porpoise. The Orca can grow to a length of 7m (23ft) and weigh 4-5,000 kg in the male and 6.6m (21ft) 2.5-3,000 kg in the female.
Despite it's name, the Killer whale has never hurt a person in the wild. It is inquisitive and approachable and aggression within a pod is rare. The pod is a close-knit family group and is stable from one generation to the next. It's members usually stay together for life. When two or more pods come together temporarily the group is called a "superpod" and may number more than 150 whales. Usually larger groups split up into two or more smaller ones as the population grows. These groups of closely related pods (clans) often develop their own dialects.
The head of the Killer whale is conical-shaped. It has an indistinct beak with a conspicuous white oval patch above and behind the eye. It's jaw is broad with relatively few large conical teeth, 10-12 pairs in each jaw, and very powerful muscles to the rear of the upper jaw. These aid the retainment of large prey that would normally resist capture.
The Orca is a versitile predator and has one of the most varied diets of all whales. Although it has been observed feeding upon penguins, seals, porpoise and large baleen whales it's reputation for doing so is probably exaggerated. For most populations of Killer whales the diet appears to be primarily fish such as salmon and cod, and squid. It's consumption of birds, penguins, sea turtles, seals, and porpoise undoubtedly depends upon local availability.
Subfamily Delphinidae.
Other Names: Orca, Great Killer Whale, Grampus.
More Killer whales live in cooler waters, especially polar regions, than tropical and subtropical regions. They are found in all seas including the Western Mediterranean, Arabian Sea and the Gulf of Aden. The largest population seems to be in Antarctica where it is estimated some 160,000 animals range.
Sightings of Killer whales are usually restricted to within 800km (500 miles) of shore. Large concentrations are usually found over the continental shelf where they prefer deep water. Sightings within the surf zone although not as common include shallow bays, inland seas and estuaries but rarely in rivers. Although the Orca has no regular long migration ice cover attributes to it's local movement in high latitudes and food availability elsewhere. Studies suggest that Killer whales adopt one of two movement characteristics called "transients" or "residents". Transients tend to form smaller pods (1 to 7), roam over a wider area, feed predominantly on mammals, vocalize less frequently, make abrupt changes in swimming direction, and often stay underwater for 5 to 15 minutes at a time. They also have a more pointed, centrally positioned dorsal fin than residents. Residents tend to form larger pods (5 to 25), have smaller home ranges, feed mainly on fish, vocalize frequently, keep to predictable routes, and rarely stay underwater for more than 4 minutes at a time.
Regarded as too small by the commercial whalers the Killer whale population has not been depleted. While early whaling practices have accounted for Killer whale deaths and indeed many other small cetaceans, it is defined as 'subsistence' or 'aboriginal' whaling and refers to the catching of whales from small boats (or from the beach) to satisfy material and cultural needs in local communities. The Indians of Vancouver and Washington on the Pacific coast of North America hunted the Gray whale and the Killer whale in this manner and for these reasons.
Opportunistic hunting applies to modern whale catchers everywhere. With a fast boat and the right equipment its hard to pass up an easy kill so it is not uncommon for vessels from the Faroes catching Fin whales to harvest small species such as Killer whales and Atlantic White-sided Dolphin. Between 1938 and 1967 the Norwegians took 1,400 Killer whales in the Northeast Atlantic. During it's 1979-80 Southern Hemisphere whaling season the Soviet fleet targeted the Killer whale, with 916 killed, along with many larger species. A perceived conflict between man and whale in pursuit of a common source of food has led to many Killer whale deaths in the Icelandic and Norwegian herring fisheries.