63 In some years, the whales have also used an offshore feeding ground in 3035 m (98115 ft) depth southeast of Chayvo bay, where benthic amphipods and cumaceans are the main prey species. 64 Some gray whales have also been seen off western Kamchatka, but to date all whales photographed there are also known from the piltun area. 34 65 A gray whale viewed from above migration edit Predicted distribution models indicate that overall range in the last glacial period was broader or more southerly distributed, and inhabitations in waters where species presences lack in present situation, such as in southern hemisphere and. 57 Range expansions due to recoveries and re-colonization in the future is likely to be happen and the predicted range covers wider than that of today. Eastern Pacific population edit a gray whale breaching in a lagoon on the coast of Mexico each October, as the northern ice pushes southward, small groups of eastern gray whales in the eastern Pacific start a two- to three-month, 8,00011,000 km (5,0006,800 mi) 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.
Whale facts, worksheets specie information For Kids - kidsKonnect
58 In the latter half of the pregnancy, the fetus experiences a rapid growth in own length and mass. Similar essay to the narrow breeding season, most calves are born within a six-week time period in mid January. 58 The calf is born tail first, and measures about 4 m (13 ft) in length. Females lactate for approximately seven months following birth, at which point calves are weaned and maternal care begins to decrease. 58 The shallow lagoon waters in which gray whales reproduce are believed to protect the newborn from sharks and orcas. 61 33 feeding edit Gray whale breaching off the coast of Santa barbara, california the whale feeds mainly on benthic crustaceans, which it eats by turning on its side (usually the right, resulting in loss of eyesight in the right eye for many older animals. 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. Mostly, the animal feeds in the northern waters during the summer; and opportunistically feeds during its migration, depending primarily on its extensive fat reserves. Calf gray whales drink 190300 US gal (7201,140 l) of their mothers' 53 fat milk per day. 62 The main feeding habitat of the western Pacific subpopulation is the shallow (515 m (1649 ft) 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.
58 Females show highly synchronized reproduction, undergoing oestrus in late november to early december. 59 During the breeding season, it is common for females to have several mates. 60 This single ovulation event is believed to coincide with the species annual migration patterns, when births can occur in warmer waters. 60 Most females show biennial reproduction, although annual births have been reported. 59 Males also show seasonal changes, experiencing an increase in testes mass that correlates with the time females undergo oestrus. 60 Currently there are no accounts of twin births, although an instance of twins in utero has been reported. 59 The gestation period for gray whales is approximately 13 12 months.
There has been gradual melting and recession of Arctic sea ice with extreme loss in 2007 rendering the northwest Passage "fully navigable". 54 The same whale was sighted again on may 30, 2010, off the coast of Barcelona, spain., a gray whale was sighted off Walvis bay, namibia. Scientists from the namibian Dolphin Project confirmed the whale's identity and thus provides the only sighting of this species in the southern Hemisphere. Photographic identification suggests that this is a different individual than the one spotted in the mediterranean lined in 2010. As of July 2013, the namibian whale was still being seen regularly. 56 Genetic analysis of fossil and prefossil gray whale remains in the Atlantic Ocean suggests several waves of dispersal from the pacific to the Atlantic related to successive periods of climactic warming - during the Pleistocene before the last glacial period and the early holocene. This information and the recent sightings of Pacific shredder gray whales in the Atlantic, suggest that another range expansion to the Atlantic may be starting. 57 Life history edit reproduction edit see also: Whale reproduction Breeding behavior is complex and often involves three or more animals. Both male and female whales reach puberty at approximately eight years of age.
46 Factors limiting or threatening current population levels include ship strikes, entanglement in fishing gear, and changes in sea-ice coverage associated with climate change. 47 Integration and recolonization edit 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. 48 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. 28 31 In mid-1980, there were three gray whale sightings in the eastern beaufort sea, placing them 585 kilometers (364 mi) further east than their known range at the time. 49 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, 50 and around the marine mammal sanctuary. These whales were darker in body color than those whales seen in sea of Okhotsk., a gray whale was sighted off the mediterranean shore of Israel. 53 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.
Facts about Whales for Kids - whale facts and Information
39 Radiocarbon dating of subfossil or fossil European (Belgium, the netherlands, Sweden, the United Kingdom) coastal remains confirms this, with whaling the possible cause. 22 Remains dating from the roman epoch were found in the mediterranean during excavation of the antique harbor of Lattara near Montpellier in 1997, raising the question of whether Atlantic gray whales migrated up and down the coast of Europe from Wadden sea to business calve. 40 41 Similarly, radiocarbon dating of American east coastal subfossil remains confirm that gray whales existed there at least through the 17th century. This population ranged at least from southampton, new York, to jupiter Island, Florida, the latest from 1675. Istory of Nantucket Island, obed Macy wrote that in the early pre-1672 colony a whale of the kind called "scragg" entered the harbor and was pursued and killed by the settlers.
Van deinse points out that the "scrag whale described. Dudley in 1725 as one of the species hunted by the early new England whalers, was almost certainly the gray whale. 43 44 Prewhaling abundance edit researchers 45 used a genetic approach to estimate pre-whaling abundance based on samples from 42 California gray whales, and reported dna variability at 10 genetic loci consistent with a population size of 76,000118,000 individuals, three to five times larger than. Noaa has collected surveys of gray whale population since at least the 1960s. They state that "the most recent population estimate from 2007 was approximately 19,000 whales, with a high probability (88) that the population is at 'optimum sustainable population' size, as defined by the marine mammal Protection Act. They speculate that the ocean ecosystem has likely changed since the prewhaling era, making a return to prewhaling numbers infeasible.
However, there have been observations of some whales showing distinctive, blackish body colors in recent years. 30 This corresponds with the dna analysis of last recorded stranding in China. 31 Differences were also observed between Korean and Chinese specimens. 29 Populations edit north Pacific edit Gray whale spouting along shores of Yachats Two pacific Ocean populations are known to exist: one of not more than 130 individuals (according to the most recent population assessment in 2008 32 ) whose migratory route is presumed. 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. 33 The western population is listed as critically endangered by the iucn.
No new reproductive females were recorded in 2010, resulting in a minimum of 26 reproductive females being observed since 1995. 32 even a very small number of additional annual female deaths will cause the subpopulation to decline. 34 North Atlantic edit The gray whale became extinct in the north Atlantic in the 18th century. 35 Other than speculations, large portions of historical characteristic of migration and distribution are unclear such as locations of calving grounds, existences of resident groups, and occurrences within Black and azov seas. They had been seasonal migrants to coastal waters of both sides of Atlantic, including the baltic sea, 36 37 Wadden sea, the gulf. Lawrence, the bay of Fundy, hudson bay (possibly 38 and Pamlico sound.
Whales - what is a whale?
Its head's ventral surface lacks the numerous prominent furrows of the related rorquals, instead bearing two parts to five shallow furrows on the throat's underside. 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.5 m (1011 ft) across and deeply notched at the center while its edges taper to a point. Pacific groups edit The two populations of Pacific gray whales (east online 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. 28 29 Since the original Asian and Atlantic populations have become extinct, it is difficult to determine the unique features among whales in these stocks.
25 Description edit 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 summary 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 26 at the surface in calm wind conditions. Gray whales measure from.9 m (16 ft) in length for newborns to 1315 m (4349 ft) for adults (females tend to be slightly larger than adult males). Newborns are a darker gray to black in color. A mature gray whale can reach 40 t (44 short tons with a typical range of 1533 t (1736 short tons). 27 A close-up of a gray whale's double blow hole and some of its encrusted barnacles 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.
rorquals, such as the minke. 14 15 But other recent studies place gray whales as being outside the rorqual clade, but as the closest relatives to the rorquals. 16 John Edward Gray placed it in its own genus in 1865, naming it in honour of physician and zoologist Daniel Frederik eschricht. 17 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. 18 The living Pacific species was described by cope as Rhachianectes glaucus in 1869. 19 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. 20 21 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. 22 Many other names have been ascribed to the gray whale, including desert whale, 23 devilfish, gray back, mussel digger and rip sack. 24 The name Eschrichtius gibbosus is sometimes seen; this is dependent on the acceptance of a 1777 description by Erxleben.
The gray whale is distributed in an eastern North Pacific (North American) population and a critically 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. 9, however, on may 8, 2010, a sighting of a gray whale was confirmed off the coast of Israel in the mediterranean sea, 10 leading some scientists to think they might be repopulating old breeding grounds that have not been used for centuries. 10, in may and June 2013 a gray whale was sighted off the coast of Namibia the first confirmed in the southern Hemisphere. 11, the round-trip journey of one gray whale has set a new record for the longest mammal migration, covering a distance of more than 22,000 kilometres across the pacific Ocean. Her migration has shown new insight into how endangered species listing are making drastic changes in their life style. 12, contents, taxonomy edit skeleton The gray whale is traditionally placed as the only living species in its genus and family.
Whale facts For Kids - whaleFacts
The gray whale eschrichtius robustus 1 also known as the grey whale, 4 gray back whale, pacific gray whale, or, california gray whale 5 is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length.9 meters (49 ft a weight of 36 tonnes (40 short tons and lives between 55 and 70 years. 6, the common name of the whale comes from the gray patches and white mottling on its dark skin. 7, gray whales were once called devil fish because of their fighting write behavior when hunted. 8, the gray whale is the sole living species in the genus. Eschrichtius, which in turn is the sole living genus in the family, eschrichtiidae. This mammal descended from filter-feeding whales that appeared at the beginning of the. Oligocene, over 30 million years ago.