An
ursid hybrid is an animal with parents from two different
speciesIn biology, a species is:* a taxonomic rank or* a unit at that rank ....
or
subspeciesSubspecies in biological classification, is 1) a taxonomic rank subordinate to species, or 2) a taxonomic unit, a taxon in that rank...
of the Ursidae (
bearBears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although there are only eight living species of bear, they are widespread, appearing in a wide variety of habitats throughout the Northern...
)
familyIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus...
. Species and subspecies of bear known to have produced offspring with another bear species or subspecies include brown bears, black bears, grizzly bears and polar bears, all of which are members of the
Ursus genusIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
. Bears not included in
Ursus, such as the
Giant PandaThe Giant Panda is a mammal native to central-western and south western China. The Giant Panda is a member of the Ursidae family. It is easily recognized by its large, distinctive black patches around the eyes, over the ears, and across its round body...
, are probably unable to produce hybrids.
An
ursid hybrid is an animal with parents from two different
speciesIn biology, a species is:* a taxonomic rank or* a unit at that rank ....
or
subspeciesSubspecies in biological classification, is 1) a taxonomic rank subordinate to species, or 2) a taxonomic unit, a taxon in that rank...
of the Ursidae (
bearBears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although there are only eight living species of bear, they are widespread, appearing in a wide variety of habitats throughout the Northern...
)
familyIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus...
. Species and subspecies of bear known to have produced offspring with another bear species or subspecies include brown bears, black bears, grizzly bears and polar bears, all of which are members of the
Ursus genusIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
. Bears not included in
Ursus, such as the
Giant PandaThe Giant Panda is a mammal native to central-western and south western China. The Giant Panda is a member of the Ursidae family. It is easily recognized by its large, distinctive black patches around the eyes, over the ears, and across its round body...
, are probably unable to produce hybrids. Note all of the confirmed hybrids listed here have been in captivity (except Grizzly/Polar bear), but there are unconfirmed reports of hybrids in the wild.
Brown bear/Black bear hybrids
In 1859, a
black bearThe American Black Bear also known as the North American black bear is the most common bear species native to North America. It lives throughout much of the continent, from northern Alaska south into Mexico and from the Atlantic Ocean to the Pacific Ocean. This includes 41 of the 50 U.S...
and a European
brown bearThe brown bear is a large bear distributed across much of northern Eurasia and North America. It weighs 100 to 680 kilograms and its largest subspecies, the Kodiak Bear, rivals the polar bear as the largest member of the bear family, and as the largest land based predator.While the brown...
were bred together in the London Zoological Gardens, but the three
cubsCubs may refer to:*Chicago Cubs, a baseball team of the National League of Major League Baseball**Iowa Cubs, a minor league baseball team of the Pacific Coast League**Daytona Cubs, a minor league baseball team of the Florida State League...
did not reach maturity. In
The Variation of Animals and Plants under DomesticationThe Variation of Animals and Plants under Domestication is a book written by Charles Darwin that was first published in January 1868.A large proportion of the book contains detailed information on the domestication of animals and plants but it also contains in Chapter XXVII a description of...
Charles DarwinCharles Robert Darwin FRS was an English naturalist who realised and presented compelling evidence that all species of life have evolved over time from common ancestors, through the process he called natural selection...
noted:
In the nine-year Report it is stated that the bears had been seen in the Zoological Gardens to couple freely, but previously to 1848 most had rarely conceived. In the Reports published since this date three species have produced young (hybrids in one case),...
Since black bears and brown bears have differing numbers of
chromosomeA chromosome is an organized structure of DNA and protein that is found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions...
s, it is unlikely that such hybrids, if proven, would be fertile.
Brown bear/Grizzly bear hybrids
Hybrids between the (European) brown bear and the
grizzly bearThe grizzly bear , also known as the silvertip bear, is a subspecies of brown bear that generally lives in the uplands of western North America....
(now considered to be a North American variety of brown bear rather than a separate species) have been bred in Cologne, Germany. See
grizzly bearThe grizzly bear , also known as the silvertip bear, is a subspecies of brown bear that generally lives in the uplands of western North America....
for taxonomy.
Brown bear/Polar bear hybrids
- Since 1874, at Halle
Halle is the largest city in the German State of Saxony-Anhalt. It is also called Halle an der Saale in order to distinguish it from Halle in North Rhine-Westphalia...
, a series of successful matings of polar bears and brown bearsThe Brown Bears is a name shared by all sports teams at Brown University, a university located in Providence, Rhode Island in the United States. The Bears are part of the Ivy League conference. Brown's mascot is Bruno. Both the men's and women's teams share the name, competing in 37 National...
were made. Some of the hybrid offspringIn biology, offspring is the product of reproduction, a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...
were exhibited by the London Zoological Society. The Halle hybrid bears proved to be fertile, both with one of the parent species and with one another. Polar bear/Brown bear hybrids are white at birth but later turn blue-brown or yellow-white.
- An adult polar bear/brown bear hybrid bred in the 19th Century is now displayed at the Rothschild Zoological Museum, Tring, England
- Crandall reported the first polar bear/brown bear crosses as occurring at a small zoo in Stuttgart
Stuttgart is the capital of the state of Baden-Württemberg in southern Germany. The sixth-largest city in Germany, Stuttgart has a population of 600,038 while the metropolitan area has a population of 5.3 million ....
, GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
in 1876 rather than Halle in 1874. A female European brown bear mated with a male polar bear resulting in twin cubs in 1876. Three further births were recorded. The young were fertile among themselves and when mated back to European brown bears and to polar bears.
- DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information...
studies indicate that some brown bears are more closely related to polar bears than they are to other brown bears. All the Ursinae species (i.e., all bears except the giant pandaThe Giant Panda is a mammal native to central-western and south western China. The Giant Panda is a member of the Ursidae family. It is easily recognized by its large, distinctive black patches around the eyes, over the ears, and across its round body...
and the spectacled bearThe Spectacled Bear , also known as the Andean Bear and locally as ukuko, jukumari or ucumari is the closest living kin of the short-faced bears of the Middle Pleistocene to Late Pleistocene age....
) appear able to crossbreedA crossbreed or crossbred is an animal with purebred parents of two different breeds, varieties, or populations. Crossbreeding refers to the process of breeding such an animal, often with the intention of creating offspring that share the traits of both parent lineages, or producing an animal with...
.
Kodiak bear/Polar bear hybrids
"Kodiak" or "Kodiak brown" is a term now applied to brown bears found in coastal regions of North America. In the far north these bears feed on salmon and often attain especially large size. "Alaskan Brown" is sometimes used for Alaskan bears, but the main distinction is how far the bear is found from the coast.
Grizzly bearThe grizzly bear , also known as the silvertip bear, is a subspecies of brown bear that generally lives in the uplands of western North America....
is the term used for the
brown bearThe brown bear is a large bear distributed across much of northern Eurasia and North America. It weighs 100 to 680 kilograms and its largest subspecies, the Kodiak Bear, rivals the polar bear as the largest member of the bear family, and as the largest land based predator.While the brown...
of the North American interior.
- In 1936, a male polar bear accidentally got into an enclosure with a female Kodiak
The brown bear is a large bear distributed across much of northern Eurasia and North America. It weighs 100 to 680 kilograms and its largest subspecies, the Kodiak Bear, rivals the polar bear as the largest member of the bear family, and as the largest land based predator.While the brown...
(Alaskan Brown) bear at the US National Zoo, resulting in three hybrid offspring. One hybrid was named Willy and grew into an immense specimen. The hybrid offspring were fertile and able to breed successfully with each other, indicating that the two species of bear are closely related. The KodiakThe brown bear is a large bear distributed across much of northern Eurasia and North America. It weighs 100 to 680 kilograms and its largest subspecies, the Kodiak Bear, rivals the polar bear as the largest member of the bear family, and as the largest land based predator.While the brown...
is also considered by many to be a variant or subspecies of the basic Arctic (circumpolar) brown bear.
- In a 1970 National Geographic article Elizabeth C. Reed mentions being foster mother to 4 hybrid bear cubs from the National Zoological Park in Washington, where her husband was director.
- In 1943, Clara Helgason described a bear shot by hunters during her childhood. This was a large, off-white bear with hair all over his paws. The presence of hair on the bottom of the feet suggests it was not an unusually colored Kodiak brown bear, but a natural hybrid with a Polar bear.
Grizzly bear/Polar bear hybrids
The Grizzly bear is now regarded by most taxonomists as a variety of brown bear,
Ursus arctos horribilis.
- Clinton Hart Merriam, taxonomist of grizzly bears, described an animal killed in 1864 at Rendezvous Lake, Barren Grounds, Canada as "buffy whitish" with a golden brown muzzle. This is considered to be a natural hybrid between a grizzly bear and polar bear.
On April 16, 2006 a polar bear of unusual appearance was shot by a sports hunter on Banks Island in the
Northwest TerritoriesThe Northwest Territories is a federal territory of Canada....
. DNA testing released May 11, 2006 proved the kill was a Grizzly/Polar Bear hybrid. This is thought to be the first recorded case of interbreeding in the wild. The bear was proven to have a polar mother and a grizzly father. The DNA testing also spared the hunter the C$1000 fine for killing a grizzly bear, and the risk of being imprisoned for up to a year. The hunter had bought a license to hunt polar bears; he did not have a license to hunt grizzly at that time.
The animal had dark rings around its eyes, similar to a panda's but not as wide. It also had remarkably long claws, a slight hump on its back, brown spots in its white coat, and a slightly indented face — the nasal "stop" between the eyes which polar bears lack. The guide leading the hunt, Roger Kuptana of Sachs Harbour in the Northwest Territories, was the first to note the oddities.
Several names were suggested for this specimen. The Idaho hunter who killed it, Jim Martell, suggested
polargrizz. The biologists of the
Canadian Wildlife ServiceThe Canadian Wildlife Service or CWS is an branch of the the Department of the Environment, also known as Environment Canada, a department of the Government of Canada....
suggested
grolar or
pizzly, as well as
nanulak, an elision of the
InuitInuit is a general term for a group of culturally similar indigenous peoples inhabiting the Arctic regions of Canada, Greenland, and Alaska...
nanuk (polar bear) and
aklak (grizzly or brown bear). Both grolar and pizzly were used by the Canadian Broadcast Corporation in widely-distributed stories.
Presently, though the mating seasons overlap, the polar bear's season begins slightly earlier than the grizzly bear's. A blog columnist for the Seattle Post-Intelligencer suggested that more hybrids may be seen as
global warmingGlobal warming is the increase in the average temperature of the Earth's near-surface air and oceans since the mid-20th century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C during the last century...
progresses and alters normal mating periods. The Canadian Wildlife Service noted that grizzly-polar hybrids born of zoo matings have proven fertile.
Grizzly bears have been sighted in what is usually polar bear territory in the Western Arctic near the Beaufort Sea, Banks Island, Victoria Island, and Melville Island. A "light chocolate colored" bear, possibly a hybrid, is reported to have been seen with polar bears near Kugluktuk in western
NunavutNunavut is the largest and newest federal territory of Canada; it was separated officially from the Northwest Territories on April 1, 1999 via the Nunavut Act and the Nunavut Land Claims Agreement Act, though the actual boundaries had been established in 1993...
.
Sloth bear hybrids
Hybrids have been produced between the
sloth bearThe Sloth Bear , also known as the Lip Bear, is a mammal of the family Ursidae which is native to the lowland forests of India, Nepal, Pakistan, Bhutan, Bangladesh, and Sri Lanka...
(
Melursus ursinus) and the Malayan sun bear (
Ursus malayanus) at
Tama ZooThe is a zoo, owned by the government of Tokyo, and located in Hino, Tokyo, Japan. Tama Zoo was opened on May 5th, 1958, originally as part of Ueno Zoo...
in
Tokyo, officially , is one of the 47 prefectures of Japan and is located on the eastern side of the main island Honshū. The twenty-three special wards of Tokyo, each governed as a city, cover the area that was once the city of Tokyo in the eastern part of the prefecture, totaling over 8 million people....
, and also between the
sloth bearThe Sloth Bear , also known as the Lip Bear, is a mammal of the family Ursidae which is native to the lowland forests of India, Nepal, Pakistan, Bhutan, Bangladesh, and Sri Lanka...
(
Melursus ursinus) and the
Asiatic black bearThe Asian black bear is a medium-sized species of bear, largely adapted for arboreal life, which occurs through much of southern Asia, northeastern China, the Russian far east and Japan. It is classed by the IUCN as a vulnerable species, largely due to deforestation and active hunting for its body...
(
Ursus thibetanus, or
Selenarctos thibetanus).
Further reading
- Martin, P.L. 1876. "Ursus arctos and Ursus maritimus. On bastards between these species born in Nill's menagerie at Stuttgart." Zoologische Garten, 1876:20-22. [Zoologische Garten, 1877:135-136. *W. Stendell and E. von Martens, tom. cit., pp.401-402.]
- ------. 1882. "On a hybrid between a male Ursus maritimus and a female Ursus arctos." Zoologische Garten, 1882:xxiii, 370.
- Kowalska, Z. 1962. "Intergeneric crossbreed of the brown bear Ursus arctos L., and the polar bear Thalarctos maritimus (Phipps)." Przeglad Zoologiczny, 6:230, 1 pl. [Polish with English summary.]
- ------. 1965. "Cross breeding between a female European brown bear and a male polar bear in Łódź Zoo." Przeglad Zoologiczny, 9:313-319. [Polish with English summary.]
- Wurster-Hill, D.H. and Bush, M. 1980: The interrelationship of chromosome banding patterns in the giant panda (Ailuropoda melanoleuca), hybrid bear (Ursus middendorfi x Thalarctos maritimus), and other carnivores. Cytogenet. Cell Genet. 27:147-154.