The gray whale (Eschrichtius robustus), also known as the grey whale,Britannica Micro.: v. IV, p. 693. 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.Recovery Strategy for the Grey Whale (Eschrichtius robustus), Atlantic Population, in Canada. Dsp-psd.pwgsc.gc.ca (2012-07-31). Retrieved on 2012-12-20. One of the longest-living gray whales currently is a female, first sighted in 1977, and estimated to be 53–55 years old . The common name of the whale comes from the gray patches and white mottling on its dark skin.Gray Whale Eschrichtius robustus. American Cetacean Society Gray whales were once called "devil fish" because of their fighting behavior when hunted, with mothers accompanied by their calves fighting viciously to protect their young if they are attacked.Gray Whale. Worldwildlife.org. Retrieved on 2012-12-20. The gray whale is the sole living species in the genus Eschrichtius. It is the sole living genus in the family Eschrichtiidae; however, some recent studies classify it as a member of the family Balaenopteridae. This mammal is descended from filter-feeding whales that appeared during the Neogene.
The gray whale is distributed in a Northeast Pacific (North American), and an endangered Northwest Pacific (Asian), population. North Atlantic populations were extirpated (perhaps by whaling) on the European coast in the 12th to 14th centuries, and on the American and African Atlantic coasts around the late 17th to early 18th centuries. However, in the 2010s and 2020s there have been rare sightings of gray whales in the North Atlantic, Mediterranean, and even off South Atlantic coasts.
Taxonomy
The gray whale is traditionally placed as the only living species in its genus and family, Eschrichtius and Eschrichtiidae,The Paleobiology Database Eschrichtiidae entry accessed on 26 December 2010 but an extinct species was discovered and placed in the genus in 2017, the Akishima whale (E. akishimaensis). Some recent studies place gray whales as being outside the rorqual clade, but as the closest relatives to the rorquals. Other recent DNA analyses have suggested that certain rorquals of the family Balaenopteridae, such as the humpback whale, Megaptera novaeangliae, and fin whale, Balaenoptera physalus, are more closely related to the gray whale than they are to some other rorquals, such as the minke whales. The American Society of Mammalogists has followed this classification.
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. 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. (Balaena gibbosa)
Taxonomic history A number of 18th century authorsE.g. ; ; described the gray whale as Balaena gibbosa, the "whale with six bosses", apparently based on a brief note by :
The gray whale was first described as a distinct species by based on a subfossil found in the brackish Baltic Sea, apparently a specimen from the now extinct north Atlantic population. Lilljeborg, however, identified it as "Balaenoptera robusta", a species of rorqual. realized that the rib and scapula of the specimen was different from those of any known rorquals, and therefore erected a new genus for it, Eschrichtius. were convinced that the bones described by Lilljeborg could not belong to a living species but that they were similar to fossils that Van Beneden had described from the harbour of Antwerp (most of his named species are now considered nomina dubia) and therefore named the gray whale Plesiocetus robustus, reducing Lilljeborg's and Gray's names to synonyms.
Charles Melville Scammon produced one of the earliest descriptions of living Pacific gray whales, and notwithstanding that he was among the whalers who nearly drove them to extinction in the lagoons of the Baja California Peninsula, they were and still are associated with him and his description of the species. At this time, however, the extinct Atlantic population was considered a separate species (Eschrischtius robustus) from the living Pacific population (Rhachianectes glaucus).
Things got increasingly confused as 19th century scientists introduced new species at an alarming rate (e.g. Eschrichtius pusillus, E. expansus, E. priscus, E. mysticetoides), often based on fragmentary specimens, and taxonomists started to use several generic and specific names interchangeably and not always correctly (e.g. Agalephus gobbosus, Balaenoptera robustus, Agalephus gibbosus). Things got even worse in the 1930s when it was finally realised that the extinct Atlantic population was the same species as the extant Pacific population, and the new combination Eschrichtius gibbosus was proposed.
Description
The gray whale has a dark slate-gray color and is covered by characteristic gray-white patterns, which are scars left by parasites that drop off in its cold feeding grounds. Individual whales are typically identified using photographs of their dorsal surface, matching the scars and patches associated with parasites that have either fallen off 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). 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.Burnie D. and Wilson D.E. (eds.) (2005) Animal: The Definitive Visual Guide to the World's Wildlife. DK Adult,
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. The beard plate can reach in length. 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. 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. The gray whale's penis can reach at least in length. Its movement speed is slow, about , but it can reach speeds of up to when in danger.
There has been a record of rather aggressive interspecies interactions between a North Pacific right whale and a pod of gray whales off California, making it the only record of possible interspecies aggression among baleen whales.Records of North Pacific Right Whales along the coasts of California, Baja, Oregon and Washington . Jim Scarff's Eclectic Home Page. Retrieved 16 March 2026. However, there has also been an observation of social interaction behavior between the two species on Sakhalin.Shipulin 2012 А давайте я вам китов покажу, а? . LiveJournal. Retrieved 16 March 2026
Pacific groups 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 has been observations of some whales showing distinctive, blackish body colors in recent years.Shpak O. (2011). Observation of the gray whale in the Laptev Sea. Standing expedition of IEE Russian Academy of Sciences. This corresponds with the DNA analysis of last recorded stranding in China. Differences were also observed between Korean and Chinese specimens.
Populations
North Pacific
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 population numbering about 27,000 individuals in the eastern Pacific, traveling between the waters off northernmost Alaska and Baja California Sur. The population of 27,000 in 2016 had however collapsed to 13,000 by 2025, due to mass starvation, malnutrition and calving failure related to warming conditions in the Arctic breeding area; calf births have fallen by 95 %.
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. The state of the population hit an all-time low in 2010. Even a very small number of additional annual female deaths will cause the subpopulation to decline. However, as of 2018, evidence has indicated that the western population is markedly increasing in number, especially off Sakhalin Island. Following this, the IUCN downlisted the population's conservation status from critically endangered to endangered.
North Atlantic The gray whale became extinct in the North Atlantic in the 18th century. They had been seasonal migrants to coastal waters of both sides of Atlantic, including the Baltic Sea,Jones L.M..Swartz L.S.. Leatherwood S.. The Gray Whale: Eschrichtius Robustus. "Eastern Atlantic Specimens". pp 41–44. Academic Press. Retrieved on 5 September 2017Global Biodiversity Information Facility. Occurrence Detail 1322462463. Retrieved on 21 September 2017 the Wadden Sea, the Gulf of St. Lawrence, the Bay of Fundy, Pamlico Sound and possibly Hudson Bay.Fisheries and Oceans Canada.