The whale feeds mainly on benthic crustaceans, which it eats by turning on its side and scooping up sediments from the sea floor. This unique feeding selection makes gray whales one of the most strongly reliant on coastal waters among baleen whales. It is classified as a baleen whale and has baleen, or whalebone, which acts like a sieve, to capture small sea animals, including amphipods taken in along with sand, water and other material. Off Vancouver Island, gray whales commonly feed on mysids. When mysids are abundant gray whales are present in fairly large numbers. Despite mysids being a prey of choice, gray whales are opportunistic feeders and can easily switch from feeding planktonically to benthically.
Feeding
Gray whale
Gray whale | Feeding
Benthic crustaceans The whale feeds mainly on benthic crustaceans, which it eats by turning on its side and scooping up sediments from the sea floor. Benthic crustaceans Benthic crustaceans
when will the new dunkirk film be released on dvd
user
18 December 2017
assistant
what is this film about?
user
Dunkirk evacuation of World War II
assistant
can you mention a few members of the cast?
user
Fionn Whitehead, Tom Glynn-Carney, Jack Lowden, Harry Styles
assistant
where was it shot?
user
Dunkirk and Urk, Netherlands
assistant
can you tell me anything about the latter place's past?
user
Until 1475 the High and Low Lordship of Urk and Emmeloord was in the hands of the Van Kuinre family
assistant
what does the economy of this place depend upon?
user
Fishery
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is there any waterbody nearby ?
user
North Sea
assistant
what kind of marine organisms are found in this sea?
user
Cod, haddock, whiting, saithe, plaice, sole, mackerel, herring, pouting, sprat, and sandeel
assistant
what kind of minerals are found in this sea?
user
Sand, gravel and rolled pieces of amber
assistant
does this place experiences any natural hazards?
user
Storm surges and tsunamis
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are whales captured here?
user
Whaling was an important economic activity from the 9th until the 13th century by by 1902 the whaling had ended
assistant
any particular whale species that was hunted?
user
Gray whale
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where are they found?
user
Eastern North Pacific and western North Pacific
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what do they feed on?
user
Mostly, the animal feeds in the northern waters during the summer; and opportunistically feeds during its migration, depending primarily on its extensive fat reserves. Another reason for this opportunistic feeding may be the result of population increases, resulting in the whales taking advantage of whatever prey is available, due to increased competition. Feeding areas during migration seem to include the Gulf of California, Monterey Bay and Big California Sur. Calf gray whales drink of their mothers' 53% fat milk per day. The main feeding habitat of the western Pacific subpopulation is the shallow ( depth) shelf off northeastern Sakhalin Island, particularly off the southern portion of Piltun Lagoon, where the main prey species appear to be amphipods and isopods.
Gray whale | Feeding
The whale feeds mainly on benthic crustaceans, which it eats by turning on its side and scooping up sediments from the sea floor. This unique feeding selection makes gray whales one of the most strongly reliant on coastal waters among baleen whales. It is classified as a baleen whale and has baleen, or whalebone, which acts like a sieve, to capture small sea animals, including amphipods taken in along with sand, water and other material. Off Vancouver Island, gray whales commonly feed on mysids. When mysids are abundant gray whales are present in fairly large numbers. Despite mysids being a prey of choice, gray whales are opportunistic feeders and can easily switch from feeding planktonically to benthically.
Gray whale | Feeding
In some years, the whales have also used an offshore feeding ground in depth southeast of Chayvo Bay, where benthic amphipods and cumaceans are the main prey species. Some gray whales have also been seen off western Kamchatka, but to date all whales photographed there are also known from the Piltun area.
Gray whale | Feeding
When gray whales feed planktonically, they roll onto their right side while their fluke remains above the surface, or they apply the skimming method seen in other baleen whales (skimming the surface with their mouth open). This skimming behavior mainly seems to be used when gray whales are feeding on crab larvae. Gray whales feed benthically, by diving to the ocean floor and rolling on to their side, (gray whales, like blue whales seem to favor rolling onto their right side) and suck up prey from the sea floor. Gray whales seem to favor feeding planktonically in their feeding grounds, but benthically along their migration route in shallower water.
Gray whale | Feeding
To catch prey, they widely open their lower jaw — almost 90° — swim through a swarm gulping, while lowering their tongue so that the head's ventral grooves expand and vastly increase the amount of water taken in. Baleen whales typically eat krill in polar or subpolar waters during summers, but can also take schooling fish, especially in the Northern Hemisphere. All baleen whales except the gray whale feed near the water surface, rarely diving deeper than or for extended periods. Gray whales live in shallow waters feeding primarily on bottom-living organisms such as amphipods.
Filter feeder | Baleen whales
Two Pacific Ocean populations are known to exist: one population that is very low, whose migratory route is presumed to be between the Sea of Okhotsk and southern Korea, and a larger one with a population of about 27,000 individuals in the eastern Pacific traveling between the waters off northernmost Alaska and Baja California Sur. Mothers make this journey accompanied by their calves, usually hugging the shore in shallow kelp beds, and fight viciously to protect their young if they are attacked, earning gray whales the moniker, devil fish. The western population has had a very slow growth rate despite heavy conservation action over the years, likely due to their very slow reproduction rate.
Gray whale | North Pacific
The feces are collected in nets and DNA is separated, individually identified, and matched with known species. The whale competes for food against clupeid fish (herring and its relatives), basking sharks, and right whales. In the North Atlantic, it feeds primarily on calanoid copepods, specifically "Calanus finmarchicus", with a secondary preference for euphausiids, in particular "Meganyctiphanes norvegica" and "Thysanoessa inermis". In the North Pacific, it feeds on similar zooplankton, including the copepod species "Neocalanus cristatus", "N. plumchrus", and "Calanus pacificus", and euphausiid species "Euphausia pacifica", "E. similis", "Thysanoessa inermis", "T. longipes", "T. gregaria" and "T. spinifera". In addition, it eats larger organisms, such as the Japanese flying squid, "Todarodes pacificus pacificus", and small fish, including anchovies ("Engraulis japonicus" and "E.
Sei whale | Feeding
Each October, as the northern ice pushes southward, small groups of eastern gray whales in the eastern Pacific start a two- to three-month, trip south. Beginning in the Bering and Chukchi seas and ending in the warm-water lagoons of Mexico's Baja California Peninsula and the southern Gulf of California, they travel along the west coast of Canada, the United States and Mexico. Traveling night and day, the gray whale averages approximately per day at an average speed of . This round trip of is believed to be the longest annual migration of any mammal. By mid-December to early January, the majority are usually found between Monterey and San Diego such as at Morro bay, often visible from shore.
Gray whale | Eastern Pacific population
The fin whale is a filter-feeder, feeding on small schooling fish, squid and crustaceans including copepods and krill. In the North Pacific, they feed on euphausiids in the genera "Euphausia", "Thysanoessa", and "Nyctiphanes", large copepods in the genus "Neocalanus", small schooling fish (e.g. the genera "Engraulis", "Mallotus", "Clupea", and "Theragra"), and squid. Based on stomach content analysis of over 19,500 fin whales caught by the Japanese whaling fleet in the North Pacific from 1952 to 1971, 64.1% contained only krill, 25.5% copepods, 5.0% fish, 3.4% krill and copepods and 1.7% squid. Nemoto (1959) analyzed the stomach contents of about 7500 fin whales caught in the northern North Pacific and Bering Sea from 1952 to 1958, found that they mainly preyed on euphausiids around the Aleutian Islands and in the Gulf of Alaska and schooling fish in the northern Bering Sea and off Kamchatka.
Fin whale | Feeding
mordax"), sardines ("Sardinops sagax"), Pacific saury ("Cololabis saira"), mackerel ("Scomber japonicus" and "S. australasicus"), jack mackerel ("Trachurus symmetricus") and juvenile rockfish ("Sebastes jordani"). Some of these fish are commercially important. Off central California, they mainly feed on anchovies between June and August, and on krill ("Euphausia pacifica") during September and October. In the Southern Hemisphere, prey species include the copepods "Neocalanus tonsus", "Calanus simillimus", and "Drepanopus pectinatus", as well as the euphausiids "Euphausia superba" and "Euphausia vallentini" and the pelagic amphipod "Themisto gaudichaudii".
Sei whale | Feeding
Northern subspecies ("B. m. musculus") – Eastern North Pacific population: This population migrates annually to the U.S. West Coast in the summer and fall to feed. Their documented migration to secondary feeding areas off Oregon, Washington, the Alaska Gyre, and the Aleutian Islands. The northern extent can seasonally overlap with the Central North Pacific population in the Gulf of Alaska. The Eastern North Pacific population migrates in the winter to their breeding grounds in the Gulf of California and the Costa Rica Dome in the Eastern Tropical Pacific. Acoustic recordings suggest that some individuals may remain on their feeding grounds and on their breeding grounds year-round.
Blue whale | Pathways and timing
Like right whales in other oceans, North Pacific right whales feed primarily on copepods, mainly the species "Calanus marshallae". They also have been reported off Japan and in the Gulf of Alaska, feeding on copepods of the genus "Neocalanus" with a small quantity of euphausiid larvae, "Euphausia pacifica". Like other right whale species, the North Pacific right whale feeds by skimming water continuously while swimming, in contrast to balaenopterid whales such as the blue and humpback whales which engulf prey in rapid lunges. Right whales do not have pleated throats. Instead they have very large heads and mouths that allows them to swim with their mouths open, the water with the copepods flowing in, then flowing sideways through the right whale's very long, very fine baleen trapping the copepods, and then out over their large lower lips.
North Pacific right whale | Feeding
Right whales feed mainly on copepods and other small invertebrates such as krill, pteropods, and larval barnacles, generally by slowly skimming through patches of concentrated prey at or below the ocean surface. Sei whales and basking sharks (sometimes minke whales as well) are in positions as food competitors and are known to feed in the same areas, swimming next to each other, but there have not been any conflicts observed between these species.
North Atlantic right whale | Feeding
This mammal is descended from filter-feeding whales that appeared at the beginning of the Oligocene, over 30 million years ago. The gray whale is distributed in an eastern North Pacific (North American), and an endangered western North Pacific (Asian), population. North Atlantic populations were extirpated (perhaps by whaling) on the European coast before AD 500, and on the American coast around the late 17th to early 18th centuries. Even so, on May 8, 2010, a sighting of a gray whale was confirmed off the coast of Israel in the Mediterranean Sea, leading some scientists to think they might be repopulating old breeding grounds that have not been visited for centuries.
Gray whale | Introduction
Miscellaneous fish, squid, and octopus played only a very minor part of the diet in two of the five years (3.6 to 4.8%). Fin whales caught off California between 1959 and 1970 fed on the pelagic euphausiid "Euphausia pacifica" (86% of sampled individuals), the more neritic euphausiid "Thysanoessa spinifera" (9%), and the northern anchovy ("Engraulis mordax") (7%); only trace amounts (<0.5% each) were found of Pacific saury ("C. saira") and juvenile rockfish ("Sebastes jordani"). In the Gulf of California, they have been observed feeding on swarms of the euphausiid "Nyctiphanes simplex".
Fin whale | Feeding
The whale watching industry provides ecotourists and marine mammal enthusiasts the opportunity to see groups of gray whales as they migrate. By late December to early January, eastern grays begin to arrive in the calving lagoons and bays on the west coast of Baja California Sur. The three most popular are San Ignacio, Magdalena Bay to the south, and, to the north, Laguna Ojo de Liebre (formerly known in English as Scammon's Lagoon after whaleman Charles Melville Scammon, who discovered the lagoons in the 1850s and hunted the grays).
Gray whale | Eastern Pacific population
The gray whale ("Eschrichtius robustus"), also known as the grey whale, gray back whale, Pacific gray whale, or California gray whale, is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of , a weight of up to and lives between 55 and 70 years, although one female was estimated to be 75–80 years of age. The common name of the whale comes from the gray patches and white mottling on its dark skin. Gray whales were once called devil fish because of their fighting behavior when hunted. The gray whale is the sole living species in the genus Eschrichtius, which in turn is the sole living genus in the family Eschrichtiidae.
Gray whale | Introduction
A population of about 200 gray whales stay along the eastern Pacific coast from Canada to California throughout the summer, not making the farther trip to Alaskan waters. This summer resident group is known as the Pacific Coast feeding group. Any historical or current presence of similar groups of residents among the western population is currently unknown, however, whalers' logbooks and scientific observations indicate that possible year-round occurrences in Chinese waters and Yellow and Bohai basins were likely to be summering grounds. Some of the better documented historical catches show that it was common for whales to stay for months in enclosed waters elsewhere, with known records in the Seto Inland Sea and the Gulf of Tosa.
Gray whale | Resident groups
It takes millions of the tiny copepods to provide the energy a right whale needs. Thus, right whales must find copepods at very high concentrations, greater than 3,000 per cubic meter to feed efficiently. National Marine Fisheries Service researchers mapped the southeast Bering Sea and the Gulf of Alaska for areas with sufficient productivity to support such concentrations and analyzed the roles of bathymetry and various gyres in concentrating copepods to such densities.
North Pacific right whale | Feeding
This rorqual is a filter feeder, using its baleen plates to obtain its food by opening its mouth, engulfing or skimming large amounts of the water containing the food, then straining the water out through the baleen, trapping any food items inside its mouth. The sei whale feeds near the surface of the ocean, swimming on its side through swarms of prey to obtain its average of about of food each day. For an animal of its size, for the most part, its preferred foods lie unusually relatively low in the food chain, including zooplankton and small fish. The whale's diet preferences has been determined from stomach analyses, direct observation of feeding behavior, and analyzing fecal matter collected near them, which appears as a dilute brown cloud.
Sei whale | Feeding
One was even found "full of baby squid" (later identified as "Lycoteuthis diadema"). In the Gulf of California, they mainly feed on Pacific sardine ("Sardinops sagax") and Pacific thread herring ("Opisthonema libertate") (about 88%), but also feed on euphausiids (mostly "Nyctiphanes simplex", 11%). They have also been observed feeding on pelagic red crabs ("Pleuroncodes planipes") off southern Baja California. In the Coral Sea, the South Pacific, and the Indian Ocean, they appear to mainly feed on euphausiids, while off Brazil, they have been observed feeding on sardines. Individuals caught off Western Australia were found with anchovies ("E. australis") in their stomachs (though these individuals may refer to Omura's whale).
Bryde's whale | Diet
It may also explain the species' migrational patterns around the North Pacific. In summer months, Baird's beaked whale can be found off the Pacific coast of Japan where demersal fish are abundant. Stomach content analysis's found that Baird's beaked whale feeds in benthic zones both day and night. This behavior differs from its other Odontocete relatives (namely the common dolphin and Dall's porpoise) who feed in mesopelagic regions during the day when the light can penetrate the water column. This suggests that Baird's beaked whale does not rely as much on its sense of sight and has evolved to navigate and hunt competently with echolocation.
Berardius | Feeding
Two stocks of minke whale are observed in the North Pacific: the "J stock" (Sea of Japan - Yellow Sea - East China sea) and the "O stock" (Okhotsk sea - west Pacific). Seasonal variations in diet exist. J stock whales' primary prey type is Japanese anchovy during May and June, Pacific saury in July and August, and krill in September. O stock whales primarily feed on krill in July and August. Most minke whales observed in 2002 (90.4%) fed solely on one prey species.
Minke whale | North Pacific
The only time they feed is during the summer months; in the winter, they live solely off fat reserves that they have stored. They are not able to feed in warmer waters such as Hawaii or Mexico because there is no adequate habitat for the fish that they consume. Cooler waters, such as those off Southeast Alaska, are teeming with fish, making this a prime feeding ground for humpback whales during their feeding season.
Bubble-net feeding | Diet
How did "Aetiocetus" feed, and what did it feed on? Its teeth are reminiscent of the bite-and-swallow strategy of archaeocetes and odontocetes, but they also possessed expanded palates. Modern mysticetes grow their baleen from this expanded palate and use the baleen to trap arthropods and fish in their mouths. This is known as bulk-feeding, in that the whale is not selecting individual prey items and does not use echolocation to find prey, as odontocetes do. Fossil mysticetes with wide, toothless palates are inferred to bulk-feed and the first occurrence of such whales is in the late Oligocene, approximately 4 to 5 million years after the first toothless mysticetes appeared.
Aetiocetus | Feeding strategy
Northern subspecies ("B. m. musculus") – Western and Central North Pacific population: Little is known about the migration of this population. In the summer, this population migrates to their feeding grounds southwest of Kamchatka, south of the Aleutian Islands, to the Gulf of Alaska, and to waters off Vancouver Island, Canada. In the winter, they migrate to low-latitude waters, including Hawaii. Acoustic data suggests that some individuals may remain on their feeding grounds year-round. Northern subspecies ("B. m. musculus") – North Atlantic population: Little is known about the winter distribution and migration patterns of this population in the North Atlantic.
Blue whale | Pathways and timing
Although identity between the Atlantic and Pacific populations cannot be proven by anatomical data, its skeleton is distinctive and easy to distinguish from that of all other living whales. Many other names have been ascribed to the gray whale, including desert whale, devilfish, gray back, mussel digger and rip sack. The name "Eschrichtius gibbosus" is sometimes seen; this is dependent on the acceptance of a 1777 description by Erxleben.
Gray whale | Taxonomy
The blue whale diet consists almost exclusively of euphausiids (krill) except off Sri Lanka. Blue whales have been observed near Magdalena Bay (along the western coast of Baja California, Mexico) feeding on pelagic red crabs. However, this has not been confirmed by recent observations or fecal samples. Other accidental or opportunistic consumption of copepods and amphipods have been documented. Blue whales feed on krill at the surface and at depths greater than 328 ft (100 m), following their prey’s diel vertical migration through the water column. The main prey species of krill targeted by blue whales varies among habitat in the different ocean basins.
Blue whale | Diet and feeding
Right whales' habitat preferences vary depending on the time of year. In spring, summer and fall, the right whales are seeking concentrations of food. In winter, in the North Atlantic and Southern Hemisphere, pregnant females and their calves generally seek out shallow, protected bays in which to give birth and raise their calves. In the North Pacific, the pattern of right whales seeking out areas of high food is the same, but female right whales and calves in the North Pacific do not show the clear pattern of concentrating in nearshore aggregations. The distribution of North Pacific right whales in winter remains a major mystery.
North Pacific right whale | Habitat preferences
They have a layer of fat, or blubber, under the skin to keep warm in the cold water. Although baleen whales are widespread, most species prefer the colder waters of the Arctic and Antarctic. Gray whales are specialized for feeding on bottom-dwelling crustaceans. Rorquals are specialized at lunge-feeding, and have a streamlined body to reduce drag while accelerating. Right whales skim-feed, meaning they use their enlarged head to effectively take in a large amount of water and sieve the slow-moving prey. Males typically mate with more than one female (polygyny), although the degree of polygyny varies with the species. Male strategies for reproductive success vary between performing ritual displays (whale song) or lek mating.
Baleen whale | Introduction
The whale shark is a filter feeder – one of only three known filter-feeding shark species (along with the basking shark and the megamouth shark). It feeds on plankton including copepods, krill, fish eggs, Christmas Island red crab larvae and small nektonic life, such as small squid or fish. It also feeds on clouds of eggs during mass spawning of fish and corals. The many rows of vestigial teeth play no role in feeding. Feeding occurs either by ram filtration, in which the animal opens its mouth and swims forward, pushing water and food into the mouth, or by active suction feeding, in which the animal opens and closes its mouth, sucking in volumes of water that are then expelled through the gills.
Whale shark | Diet
The two parvorders, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have diverged around thirty-four million years ago. Baleen whales have bristles made of keratin instead of teeth. The bristles filter krill and other small invertebrates from seawater. Grey whales feed on bottom-dwelling mollusks. Rorqual family (balaenopterids) use throat pleats to expand their mouths to take in food and sieve out the water. Balaenids (right whales and bowhead whales) have massive heads that can make up 40% of their body mass. Most mysticetes prefer the food-rich colder waters of the Northern and Southern Hemispheres, migrating to the Equator to give birth.
Cetacea | Baleen whales and toothed whales
raschii", and "T. longipes") were the predominant prey around the Aleutian Islands and in the Gulf of Alaska. Prey varied by region in the Kuril Islands area, with euphausiids ("T. longipes", "T. inermis", and "T. raschii") and copepods ("Neocalanus plumchrus" and "N. cristatus") being the main prey in the northern area and Japanese flying squid ("Todarodes pacificus pacificus") and small schooling fish (e.g. Pacific saury, "Cololabis saira"; and Japanese anchovy, "Engraulis japonicus") dominating the diet in the southern area. Of the fin whale stomachs sampled off British Columbia between 1963 and 1967, euphausiids dominated the diet for four of the five years (82.3 to 100% of the diet), while copepods only formed a major portion of the diet in 1965 (35.7%).
Fin whale | Feeding
Humpback whales have a vertical throat roughly the size of a grapefruit. They cannot physically swallow anything larger than that. They are carnivores and primarily feed on small fish such as krill, juvenile salmon, and herring. They are also baleen whales, which means that they do not have teeth, so they must be able to eat things that they can swallow whole. They have several vertical grooves running down the length of their body so that they can hold large volumes of water and fish at one time. They feed for up to twenty-two hours a day, taking in anywhere from 4,400-5,500 pounds of food per day.
Bubble-net feeding | Diet
This was the first of 11 winters from 1855 through 1865 known as the "bonanza period", during which gray whaling along the coast of Baja California reached its peak. Not only were the whales taken in Magdalena Bay, but also by ships anchored along the coast from San Diego south to Cabo San Lucas and from whaling stations from Crescent City in northern California south to San Ignacio Lagoon. During the same period, vessels targeting right and bowhead whales in the Gulf of Alaska, Sea of Okhotsk, and the Western Arctic would take the odd gray whale if neither of the more desirable two species were in sight.
Gray whale | Eastern population
Several whales seen off Sakhalin and on Kamchatka Peninsula are confirmed to migrate towards eastern side of Pacific and join the larger eastern population. In January 2011, a gray whale that had been tagged in the western population was tracked as far east as the eastern population range off the coast of British Columbia. Recent findings from either stranded or entangled specimens indicate that the original western population have become functionally extinct and possibly all the whales appeared on Japanese and Chinese coasts in modern times are vagrants or re-colonizers from the eastern population. In mid-1980, there were three gray whale sightings in the eastern Beaufort Sea, placing them further east than their known range at the time.
Gray whale | Integration and recolonization
All whales are carnivorous and predatory. Odontocetes, as a whole, mostly feed on fish and cephalopods, and then followed by crustaceans and bivalves. All species are generalist and opportunistic feeders. Mysticetes, as a whole, mostly feed on krill and plankton, followed by crustaceans and other invertebrates. A few are specialists. Examples include the blue whale, which eats almost exclusively krill, the minke whale, which eats mainly schooling fish, the sperm whale, which specialize on squid, and the grey whale which feed on bottom-dwelling invertebrates. The elaborate baleen "teeth" of filter-feeding species, mysticetes, allow them to remove water before they swallow their planktonic food by using the teeth as a sieve.
Whale | Foraging and predation
The gray whale has a dark slate-gray color and is covered by characteristic gray-white patterns, scars left by parasites which drop off in its cold feeding grounds. Individual whales are typically identified using photographs of their dorsal surface and matching the scars and patches associated with parasites that have fallen off the whale or are still attached. They have two blowholes on top of their head, which can create a distinctive heart-shaped blow at the surface in calm wind conditions. Gray whales measure from in length for newborns to for adults (females tend to be slightly larger than adult males).
Gray whale | Description
The head of the bowhead whale comprises a third of its body length, creating an enormous feeding apparatus. Bowhead whales are filter feeders, feeding by swimming forward with mouth wide open. The whale has hundreds of overlapping baleen plates consisting of keratin hanging from each side of the upper jaw. The mouth has a large, upturning lip on the lower jaw that helps to reinforce and hold the baleen plates within the mouth. This also prevents buckling or breakage of the plates from the pressure of the water passing through them as the whale advances. To feed, water is filtered through the fine hairs of keratin of the baleen plates, trapping the prey inside near the tongue where it is then swallowed.
Bowhead whale | Feeding
Humans and killer whales (orcas) are the adult gray whale's only predators, although orcas are the more prominent predator. Aboriginal hunters, including those on Vancouver Island and the Makah in Washington, have hunted gray whales. Commercial whaling by Europeans of the species in the North Pacific began in the winter of 1845–46, when two United States ships, the "Hibernia" and the "United States", under Captains Smith and Stevens, caught 32 in Magdalena Bay. More ships followed in the two following winters, after which gray whaling in the bay was nearly abandoned because "of the inferior quality and low price of the dark-colored gray whale oil, the low quality and quantity of whalebone from the gray, and the dangers of lagoon whaling." Gray whaling in Magdalena Bay was revived in the winter of 1855–56 by several vessels, mainly from San Francisco, including the ship "Leonore", under Captain Charles Melville Scammon.
Gray whale | Eastern population
All modern mysticetes are obligate filter feeders, using their baleen to strain small prey items (including small fish, krill, copepods, and zooplankton) from seawater. Despite their carnivorous diet, a 2015 study revealed they house gut flora similar to that of terrestrial herbivores. Different kinds of prey are found in different abundances depending on location, and each type of whale is adapted to a specialized way of foraging. There are two types of feeding behaviors: skim-feeding and lunge-feeding, but some species do both depending on the type and amount of food. Lunge-feeders feed primarily on euphausiids (krill), though some smaller lunge feeders (e.g.
Baleen whale | Foraging
The two populations of Pacific gray whales (east and west) are morphologically and phylogenically different. Other than DNA structures, differences in proportions of several body parts and body colors including skeletal features, and length ratios of flippers and baleen plates have been confirmed between Eastern and Western populations, and some claims that the original eastern and western groups could have been much more distinct than previously thought, enough to be counted as subspecies. Since the original Asian and Atlantic populations have become extinct, it is difficult to determine the unique features among whales in these stocks. However, there have been observations of some whales showing distinctive, blackish body colors in recent years.
Gray whale | Pacific groups
John Edward Gray placed it in its own genus in 1865, naming it in honour of physician and zoologist Daniel Frederik Eschricht. The common name of the whale comes from its coloration. The subfossil remains of now extinct gray whales from the Atlantic coasts of England and Sweden were used by Gray to make the first scientific description of a species then surviving only in Pacific waters. The living Pacific species was described by Cope as "Rhachianectes glaucus" in 1869. Skeletal comparisons showed the Pacific species to be identical to the Atlantic remains in the 1930s, and Gray's naming has been generally accepted since.
Gray whale | Taxonomy
Killer whales and bottlenose dolphins have also been known to drive their prey onto a beach to feed on it, a behaviour known as beach or strand feeding. The shape of the snout may correlate with tooth number and thus feeding mechanisms. The narwhal, with its blunt snout and reduced dentition, relies on suction feeding. Sperm whales usually dive between , and sometimes , in search of food. Such dives can last more than an hour. They feed on several species, notably the giant squid, but also the colossal squid, octopuses, and fish like demersal rays, but their diet is mainly medium-sized squid.
Toothed whale | Foraging and predation
minke whales) also prey on schools of fish. Skim-feeders, like bowhead whales, feed upon primarily smaller plankton such as copepods. They feed alone or in small groups. Baleen whales get the water they need from their food, and their kidneys excrete excess salt. The lunge-feeders are the rorquals. To feed, lunge-feeders expand the volume of their jaw to a volume bigger than the original volume of the whale itself. To do this, the mouth inflates, which causes the throat pleats to expand, increasing the amount of water that the mouth can store. Just before they ram the baitball, the jaw swings open at almost a 90° angle and bends which lets in more water.
Baleen whale | Foraging
Offshore gas and oil development in the Okhotsk Sea within of the primary feeding ground off northeast Sakhalin Island is of particular concern. Activities related to oil and gas exploration, including geophysical seismic surveying, pipelaying and drilling operations, increased vessel traffic, and oil spills, all pose potential threats to western gray whales. Disturbance from underwater industrial noise may displace whales from critical feeding habitat. Physical habitat damage from drilling and dredging operations, combined with possible impacts of oil and chemical spills on benthic prey communities also warrants concern. The western gray whale population is considered to be endangered according to IUCN standards.
Gray whale | Threats
According to the Government of Canada's Management Plan for gray whales, threats to the eastern North Pacific population of gray whales include: increased human activities in their breeding lagoons in Mexico, climate change, acute noise, toxic spills, aboriginal whaling, entanglement with fishing gear, boat collisions, and possible impacts from fossil fuel exploration and extraction. Western gray whales are facing, the large-scale offshore oil and gas development programs near their summer feeding ground, as well as fatal net entrapments off Japan during migration, which pose significant threats to the future survival of the population. The substantial nearshore industrialization and shipping congestion throughout the migratory corridors of the western gray whale population represent potential threats by increasing the likelihood of exposure to ship strikes, chemical pollution, and general disturbance.
Gray whale | Threats
By 1934, the western gray whale was near extinction. From 1891 to 1966, an estimated 1,800–2,000 gray whales were caught, with peak catches of between 100 and 200 annually occurring in the 1910s. As of 2001, the Californian gray whale population had grown to about 26,000. As of 2016, the population of western Pacific (seas near Korea, Japan, and Kamchatka) gray whales was an estimated 200.
Gray whale | Western population
In the northern Bering Sea (north of 58°N), their main prey species were capelin ("Mallotus villosus"), Alaska pollock ("Theragra chalcogramma") and Pacific herring ("Clupea pallasii"); they also consumed saffron cod ("Eleginus gracilis"). Arctic krill ("Thysanoessa raschii") was the only species of euphausiid found in the stomachs of fin whales in the northern Bering Sea. Off Kamchatka, they appeared to primarily feed on herring. They also took large quantities of the copepod "Neocalanus cristatus" around the Aleutian Islands and in Olyutorsky Bay off northeast Kamchatka, areas where the species was abundant. Five species of euphausiid ("Euphausia pacifica", "Thysanoessa spinifera", "T. inermis", "T.
Fin whale | Feeding
The diet consists of mostly zooplankton, which includes copepods, amphipods, and many other crustaceans. About of food are consumed each day. While foraging, bowheads are solitary or occur in groups of two to 10 or more.
Bowhead whale | Feeding
The species is now only known from the northern Pacific Ocean where gray whales are found. The gray whale was present in the northern Atlantic Ocean between the Late Pleistocene and recent times, and "C. rhachianecti" fossils have been found on a beach in the Netherlands, showing that the barnacle must also have been present. This barnacle has been found between January and March for several years in captive beluga whales in San Diego Bay, near a route used by migratory gray whales. The barnacles have evoked a skin reaction in the beluga whales resulting in the eviction of the barnacles, which suggests an immune response.
Cryptolepas rhachianecti | Distribution
Eschrichtiidae only has one living member: the gray whale. It is the only benthic feeding baleen whale, filtering small organisms from the mud of shallow seas. They also have a gestation period of over a year, which is unusual for baleen whales.
List of cetaceans | Family Eschrichtiidae: gray whale
Bryde's whales feed on a wide variety of fish, planktonic crustaceans, and cephalopods. In the western North Pacific, Bryde's whales caught by Japanese scientific whaling vessels (2000–2007) mainly fed on Japanese anchovy ("Engraulis japonicus", 52%) and various species of euphausiid (36%, including "Euphausia similis", "E. gibboides", "Thysanoessa gregaria", and "Nematoscelis difficilis"), as well as oceanic lightfish ("Vinciguerria nimbaria", nearly 3%), and mackerels ("Scomber" spp., less than 2%). The prey differed by location and season. In coastal areas, euphausiids dominated the diet, comprising 89 and 75% of the diet in May and June, respectively. Further offshore, Japanese anchovy was the dominant species, accounting for nearly 100% of the diet in late summer.
Bryde's whale | Diet
Factors limiting or threatening current population levels include ship strikes, entanglement in fishing gear, and changes in sea-ice coverage associated with climate change.
Gray whale | Prewhaling abundance
Both species have a sac in the lower portion of their intestinal tracts that contains up to 12 liters of dark reddish-brown fluid, which can be ejected to confuse or discourage potential predators.
Pygmy sperm whale | Diet/foraging behavior
Past thinking about North Pacific right whale migration presumed a paradigm of migratory behavior similar to that of other baleen whales in the North Pacific. Perhaps the extreme example of North Pacific whale migration is that of Gray whale. Nearly all the Gray whales that summer in the Bering Sea migrate to wintering grounds off Baja California. In summer and winter, nearly all the gray whales are either at the northern or southern ends of their range. Initially scientists assumed that North Pacific right whales had similar migratory pattern. Analysis of 19th century pelagic whaling suggest that North Pacific right whales do migrate south in winter, but the whaling data did not indicate any specific migratory routes as seen in gray whales.
North Pacific right whale | Migration
Almost all of the 400 North Atlantic right whales live in the western North Atlantic Ocean. In northern spring, summer and autumn, they feed in areas off the Canadian and northeast U.S. coasts in a range stretching from New York to Newfoundland. Particularly popular feeding areas are the Bay of Fundy and Cape Cod Bay. In winter, they head south towards Georgia and Florida to give birth. There have been a smattering of sightings further east over the past few decades; several sightings were made close to Iceland in 2003. These are possibly the remains of a virtually extinct eastern Atlantic stock, but examination of old whalers' records suggests they are more likely to be strays.
Right whale | North Atlantic right whale
Former feeding areas were once spread over large portions on mid-Honshu to northern Hokkaido, and at least whales were recorded for majority of annual seasons including wintering periods at least along east coasts of Korean Peninsula and Yamaguchi Prefecture. Some recent observations indicate that historic presences of resident whales are possible: a group of two or three were observed feeding in Izu Ōshima in 1994 for almost a month, two single individuals stayed in Ise Bay for almost two months in the 1980s and in 2012, the first confirmed living individuals in Japanese EEZ in the Sea of Japan and the first of living cow-calf pairs since the end of whaling stayed for about three weeks on the coastline of Teradomari in 2014.
Gray whale | Resident groups
The gray whale also lacks a dorsal fin, instead bearing 6 to 12 dorsal crenulations ("knuckles"), which are raised bumps on the midline of its rear quarter, leading to the flukes. This is known as the dorsal ridge. The tail itself is across and deeply notched at the center while its edges taper to a point.
Gray whale | Description
Northern bottlenose feed mainly on deep water squid, primarily Gonatus sp., and bottom fish, such as Greenland halibut. Foraging dives can last an hour or more at depths reaching over 1000 meters. A small percentage of northern bottlenose whales have been also been observed feeding on redfish, rabbitfish, spiny dogfish, and skate.
Northern bottlenose whale | Feeding
The right whales' diets consist primarily of zooplankton, primarily the tiny crustaceans called copepods, as well as krill, and pteropods, although they are occasionally opportunistic feeders. As with other baleens, they feed by filtering prey from the water. They swim with an open mouth, filling it with water and prey. The whale then expels the water, using its baleen plates to retain the prey. Prey must occur in sufficient numbers to trigger the whale's interest, be large enough that the baleen plates can filter it, and be slow enough that it cannot escape. The "skimming" may take place on the surface, underwater, or even at the ocean's bottom, indicated by mud occasionally observed on right whales' bodies.
Right whale | Diet and predation
This species typically lives in the Southern Hemisphere between 30 and 45°, and is typically observed at depths of . Many strandings have occurred off New Zealand, but others have happened off Australia, South Africa, South America, and the Falkland Islands. This species has been sighted in groups off the coast of Madagascar and in the Antarctic area. Oddly, one specimen stranded off the Netherlands, in a different hemisphere and several thousand miles away from all other strandings. No population estimates exist, but they are believed to be rather common.
Gray's beaked whale | Population and distribution
They feed on fish, squid, and similar oceanic food. Some will follow fishing boats to take scraps, commonly the sooty shearwater; these species also commonly follow whales to feed on fish disturbed by them. Their primary feeding technique is diving, with some species diving to depths of .
Shearwater | Feeding
Stable isotope analysis from 2003 shows minke whales in the north Atlantic also feed on prey from lower trophic levels as well.
Minke whale | North Atlantic
Based on the stomach contents of Bryde's whales caught by Japanese pelagic whaling expeditions in the North Pacific in the 1970s, the majority where found to feed on euphausiids (nearly 89%), whereas only about 11% fed on fish. Off South Africa, prey preferences differed between the inshore and offshore forms. The former mainly feed on anchovies ("Engraulis capensis", 83%), maasbankers ("Trachurus trachurus", 36%), and pilchards ("Sardinops ocellata", 33%), with only one (or 3%) being found with euphausiids ("Nyctiphanes capensis"). The latter, however, mainly feed on euphausiids (primarily "Euphausia lucens", but also "E. recurva", "N. capensis", and "Thysanoessa gregaria"), as well as various deep-sea fish (including Mueller's pearlside, "Maurolicus muelleri", and a species of "Lestidium").
Bryde's whale | Diet
Newborns are a darker gray to black in color. A mature gray whale can reach , with a typical range of , making them the ninth largest sized species of cetacean. Notable features that distinguish the gray whale from other mysticetes include its baleen that is variously described as cream, off-white, or blond in color and is unusually short. Small depressions on the upper jaw each contain a lone stiff hair, but are only visible on close inspection. Its head's ventral surface lacks the numerous prominent furrows of the related rorquals, instead bearing two to five shallow furrows on the throat's underside.
Gray whale | Description
There remain only much smaller concentrations in the Eastern North Pacific (1,647), Central North Pacific (63–133), North Atlantic (1,000–2,000), Antarctic (2,280), New Zealand (718), Northern Indian Ocean (270) and Chile (570-760).
Blue whale | Introduction
Females also have teeth, but they are buried in the jaw and do not erupt. The dorsal fin is relatively small, at and about two thirds of the way back on their bodies. It is falcate (sickle-shaped) and usually pointed. The back is mid-to-dark grey with a lighter underside. They weigh approximately . The oldest recorded age, determined by counting annual growth layers from a tooth in a whaled specimen was 37. Calves have prolonged weaning and nursing continues until juveniles are 3-4 years old. Males typically become sexually mature at around the age of 9 and females at the age of 10.
Northern bottlenose whale | Description
When feeding, they blow 5–7 times in quick succession, but while traveling or resting will blow once every minute or two. On their terminal (last) dive they arch their back high out of the water, but rarely raise their flukes out of the water. They then dive to depths of up to when feeding or a few hundred feet when resting or traveling. The average feeding dive off California and Baja lasts 6 minutes, with a maximum of 17 minutes; when traveling or resting they usually dive for only a few minutes at a time.
Fin whale | Breathing
Several species of cetaceans are found near the Farallon Islands, most frequently gray whales, blue whales, and humpback whales. Blue whales and humpback whales are most frequently found near the islands in the summer and fall, when strong upwelling may support a rich pelagic food web. Orca whales are also found around the islands. Gray whales are reliably found near the Farallones during their spring migration north and the fall and winter migration south. Some gray whales may also be found during the summer, when a few whales skip the trip north to Alaska and spend the summer months off the coast of Canada and the continental United States.
Farallon Islands | Whales
In spring, summer and autumn, the western North Atlantic population feeds in a range stretching from Massachusetts to Newfoundland. Particularly popular feeding areas are the Bay of Fundy, the Gulf of Maine and Cape Cod Bay. In winter, they head south towards Georgia and Florida to give birth. According to census of individual whales identified using photo-identification techniques, the latest available stock assessment data (August 2012) indicates that a minimum of 396 recognized individuals were known to be alive in the western North Atlantic in 2010, up from 361 in 2005. Distributions within other parts of Bay of Fundy is rather unknown, although whales are occasionally observed at various locations in northern parts such as in Baxters Harbour or at Campobello Island.
North Atlantic right whale | Western population
In 2005, two conservation biologists proposed a plan to airlift 50 gray whales from the Pacific Ocean to the Atlantic Ocean. They reasoned that, as Californian gray whales had replenished to a suitable population, surplus whales could be transported to repopulate the extinct British population. this plan has not been undertaken.
Gray whale | Rewilding proposal
This corresponds with the DNA analysis of last recorded stranding in China. Differences were also observed between Korean and Chinese specimens.
Gray whale | Pacific groups
The shallow lagoon waters in which gray whales reproduce are believed to protect the newborn from sharks and orcas. On 7 January 2014, a pair of newborn or aborted conjoined twin gray whale calves were found dead in the Laguna Ojo de Liebre (Scammon's Lagoon), off the west coast of Mexico. They were joined by their bellies.
Gray whale | Reproduction
A whale's baleen plates play the most important role in its filter-feeding process. To feed, a baleen whale opens its mouth widely and scoops in dense shoals of prey (such as krill, copepods, small fish, and sometimes birds that happen to be near the shoals), together with large volumes of water. It then partly shuts its mouth and presses its tongue against its upper jaw, forcing the water to pass out sideways through the baleen, thus sieving out the prey, which it then swallows.
Baleen | Filter feeding
All whales are carnivorous and predatory. Odontocetes, as a whole, mostly feed on fish and cephalopods, and then followed by crustaceans and bivalves. All species are generalist and opportunistic feeders. Some may forage with other kinds of animals, such as other species of whales or certain species of pinnipeds. One common feeding method is herding, where a pod squeezes a school of fish into a small volume, known as a bait ball. Individual members then take turns plowing through the ball, feeding on the stunned fish. Coralling is a method where dolphins chase fish into shallow water to catch them more easily.
Toothed whale | Foraging and predation
Balaenids are the right whales. These animals have very large heads, which can make up as much as 40% of their body mass, and much of the head is the mouth. This allows them to take in large amounts of water into their mouths, letting them feed more effectively. Eschrichtiids have one living member: the grey whale. They are bottom feeders, mainly eating crustaceans and benthic invertebrates. They feed by turning on their sides and taking in water mixed with sediment, which is then expelled through the baleen, leaving their prey trapped inside. This is an efficient method of hunting, in which the whale has no major competitors.
Whale | Mysticetes
The throats of all beaked whales have a bilaterally paired set of grooves that are associated with their unique feeding mechanism, suction feeding. Instead of capturing prey with their teeth, beaked whales suck it into their oral cavity. Suction is aided by the throat grooves, which stretch and expand to accommodate food. Their tongues can move very freely. By suddenly retracting the tongue and distending the gular (throat) floor, pressure immediately drops within the mouth, sucking the prey in with the water. Dietary information is available from stomach contents analyses of stranded beaked whales and from whaling operations. Their preferred diet is primarily deep-water squid, but also benthic and benthopelagic fish and some crustaceans, mostly taken near the sea floor.
Beaked whale | Feeding
For comparison, a population of 20,000 or more animals is comparable to the current and presumably early 19th century population of Gray whales in the North Pacific
North Pacific right whale | Historic population
Adult males often carry linear scars that probably result from fighting, and both males and females may display circular scars from cookiecutter shark bites. "M. grayi" are long and weigh around . They are believed to be around long when born.
Gray's beaked whale | Description
Like other mesoplodont whales, it is thought that Deraniyagala's whale feeds mainly on deep-sea squid-and-fish.
Deraniyagala's beaked whale | Diet
The 19th century whalers travelled north in spring and south in fall. To some extent the apparent North Pacific right whale migration shown in the whaling data is an artifact of bias in the whaling effort. More recent studies of right whales in North Atlantic and the North Pacific suggest a migratory pattern that is quite different than the gray whale example. In the North Atlantic, many right whales remain in the northern part of their range throughout winter. It appears that while some right whales migrate far south to warmer waters, a substantial percentage of the population either does not migrate as far south or may not migrate at all.
North Pacific right whale | Migration
Recent increases in sightings are confirmed in Arctic areas of the historic range for Atlantic stocks, most notably on several locations in the Laptev Sea including the New Siberian Islands in the East Siberian Sea, and around the marine mammal sanctuary of the Franz Josef Land, indicating possible earlier pioneers of re-colonizations. These whales were darker in body color than those whales seen in Sea of Okhotsk. In May 2010, a gray whale was sighted off the Mediterranean shore of Israel. It has been speculated that this whale crossed from the Pacific to the Atlantic via the Northwest Passage, since an alternative route around Cape Horn would not be contiguous to the whale's established territory.
Gray whale | Integration and recolonization
It is estimated M. carlshubbi are along the coast of Japan and Pacific coast of North America. The distribution along North America extends from San Diego to Prince Rupert. Southern limit is unknown but the northern limit is Vancouver Island. Distribution is probably not directly related to the character of the water mass but rather follows the distribution of the prey species it feeds on. M. carlshubbi follows prey items in intermediate and deep-water masses, rather than surface water masses.
Hubbs' beaked whale | Population and distribution
Rorquals have a higher proportion of muscle tissue and tend to be negatively buoyant, whereas right whales have a higher proportion of blubber and are positively buoyant. Gray whales are easily distinguished from other extant cetaceans by their sleet-gray color, dorsal ridges (knuckles on the back), and their gray-white scars left from parasites. As with the rorquals, their throat pleats increase the capacity of their throats, allowing them to filter larger volumes of water at once. Gray whales are bottom-feeders, meaning they sift through sand to get their food. They usually turn on their sides, scoop up sediment into their mouths and filter out benthic creatures like amphipods, which leave noticeable marks on their heads.
Baleen whale | Differences between families
Bubble net feeding does not occur everywhere. Alaska's cold waters and the high amounts of sun exposure in the summer time produce food for humpbacks. Areas such as Antarctica and the North Pacific are host to diverse marine ecosystems that provide adequate feeding opportunities for humpback whales. Southeast Alaska, for example, is home to coastal glaciers that provide plentiful nutrients for suitable fish habitats. Areas with warmer waters such as Mexico and Hawaii where whales go to breed do not provide attractive habitats for fish which is why humpback whales rely on their fat reserves they have from their feeding season.
Bubble-net feeding | Setting
They have been documented feeding in areas such as Southeast Alaska and off the coast of Antarctica. During the other half of the year humpbacks will spend time in their breeding grounds where they do not eat at all. During their feeding season humpback whales will actively feed for up to twenty-two hours a day. They do this so they can store enough fat reserves to live through their breeding season.
Bubble-net feeding | Introduction
Later, NMFS split the "northern right whale" into "E. glacialis" and "E. japonica", and reissued its rule. Critical habitats must contain one or more "primary constituent elements" (PCEs) that are essential to the conservation of the species. NMFS identified as PCEs: species of large zooplankton in right whale feeding areas, in particular the copepods "Calanus marshallae", "Neocalanus cristatus", and "Thysanoessa raschii" whose high lipid content and occurrence make them preferred prey items., and physical concentrating mechanisms, physical and biological features that aggregate prey into densities high enough to support efficient feeding. NMFS simply used repeated right whale sightings in the same small area in spring and summer as a proxy for the presumed PCEs.
North Pacific right whale | Critical habitat
Unlike other baleen whales, "Janjucetus" did not use baleen to filter feed, and instead used teeth to catch large prey such as fish and sharks. Its skull morphology seems to be convergent with the modern-day leopard seal ("Hydrurga leptonyx"), and so it may have used a similar grip-and-tear feeding method. However, it is possible that the front teeth interlocked, and the cheek teethed sheared against each other when the mouth was closed, which perhaps allowed the whale to filter feed similar to the modern day crabeater seal ("Lobodon carcinophaga"). This may have been a precursor to the evolution of baleen and associated feeding habits.
Janjucetus | Palaeoecology
During the winter and spring (December–May), gray whales can be seen from shore on their annual migration (the best spot being Point Vicente), while blue whales are often seen between July and October. Fin whales, minke whales, orcas, and various species of dolphins can be seen year-round. In spring, summer, and fall at the Farallon Islands off San Francisco, one may see humpbacks, grays, and blue whales. In Mexico, the various lagoons of Baja California Sur become breeding habitat for gray whales in February and March. Humpback whales can be seen off the southern tip of Baja California, and off Puerto Vallarta in Jalisco on the west coast of Mexico, and Barra de Potosi on the south coast of Mexico in the state of Guerrero.
Whale watching | Northeast Pacific –Mexico and United States
Melon-headed whales feed primarily on pelagic and mesopelagic squid and small fish. Crustaceans (shrimp) have also been reported from stomach contents. Mesopelagic squid and fish species exhibit diel vertical migration behavior, inhabiting greater depths during the day and moving hundreds of meters to shallower depths after dusk to feed on plankton. Melon-headed whales feed at night, when their prey is within the upper of the water column. In the Hawaiian Islands, individuals fitted with depth-transmitting satellite tags made night-time foraging dives that had an average range of , with a maximum dive depth of recorded.
Melon-headed whale | Foraging
Based on the stomach contents of stranded whales, these whales primarily feed on pelagic squid, such as "Octopoteuthis deletron"; found within the remains of in the female's stomach. Some unidentified vertebrate parts were also present. Assuming Perrin's beaked whales share the same diet as other beaked whales, they likely consume octopus and fish as well.
Perrin's beaked whale | Diet
Because of their size and need to migrate, gray whales have rarely been held in captivity, and then only for brief periods of time. The first captive gray whale, who was captured in Scammon's Lagoon, Baja California in 1965, was named Gigi and died two months later from an infection. The second gray whale, who was captured in 1972 from the same lagoon, was named Gigi II and was released a year later after becoming too large for the facilities. The last gray whale, J.J., first beached herself in Marina del Rey, California where she was rushed to SeaWorld San Diego.
Gray whale | Captivity
Not much is known about its feeding habits but what is known is that they feed mainly on zooplankton and zoobenthos. Cannibalism has been reported among smaller juveniles.
Bay whiff | Diet
australis" have been known to reach Kiribati, Gabon, and "E. glacialis" likely migrated south to Mauritania to Senegal in the past.
North Pacific right whale | Western North Pacific
There are very few reports of right whales in the western North Pacific. A remnant population of right whales persists in the Sea of Okhotsk at least in the summer, along with remnant populations of the western populations of gray and bowhead whales. The distribution of these three species is quite different. In summer bowheads inhabit the northwestern corner of the Sea of Okhotsk around Academy and Ulban Bays to the Shantar Islands, while gray whales stay close to Sakhalin Island, near massive new energy developments. In contrast, the right whales inhabit the southern Sea of Okhotsk around the Kuril Islands and east of Sakhalin Island.
North Pacific right whale | Northwestern Pacific
For most of the Oligocene and Miocene, whales generally stayed well below in length. Large size in baleen whales was thought to be linked to the evolution of baleen and bulk feeding behavior, however "Llanocetus" is evidence that gigantism evolved multiple times in baleen whales. The size of "Llanocetus" is probably due to its polar environment or potential long-distance traveling.
Llanocetus | Description
Sperm whales usually dive between , and sometimes , in search of food. Such dives can last more than an hour. They feed on several species, notably the giant squid, but also the colossal squid, octopuses, and fish such as demersal rays, but their diet is mainly medium-sized squid. Some prey may be taken accidentally while eating other items. Most of what is known about deep-sea squid has been learned from specimens in captured sperm whale stomachs, although more recent studies analysed faeces. One study, carried out around the Galápagos, found that squid from the genera "Histioteuthis" (62%), "Ancistrocheirus" (16%), and "Octopoteuthis" (7%) weighing between were the most commonly taken.
Sperm whale | Diet
"T. grayi" eats worms, insects, small snails, slugs, and small fishes (if it can catch one).
Tropidophorus grayi | Diet
There is little information on the foraging behavior of Baird's beaked whales and their ecological role in the marine ecosystem.
Berardius | Feeding