Ursid hybrid
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An ursid hybrid is an animal with parents from two different species or subspecies of the Ursidae (bear) family. 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 genus. Bears not included in Ursus, such as the Giant Panda, are probably unable to produce hybrids.
Brown bear/Black bear hybrids
In 1859, a black bear and a European brown bear were bred together in the London Zoological Gardens, but the three cubs did not reach maturity. In "The Variation Of Animals And Plants Under Domestication," Charles Darwin 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)...
Brown bear/Grizzly bear hybrids
Hybrids between the (European) brown bear and the grizzly bear (now considered to be a North American variety of brown bear rather than a separate species) have been bred in Cologne, Germany. See grizzly bear for taxonomy.Brown bear/Polar bear hybrids
- Since 1874, at Halle, a series of successful matings of polar bears and brown bears were made. Some of the hybrid offspring 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, Germany 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 studies indicate that some brown bears are more closely related to polar bears than they are to other brown bears, raising the question whether they are truly separate species. All the Ursinae species (i.e., all bears except the giant panda and the spectacled bear) appear able to crossbreed.
Kodiak bear/Polar bear hybrids
"Kodiac" or "Kodiac 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 bear is the term used for the brown bear of the North American interior.
- In 1936, a male polar bear accidentally got into an enclosure with a female Kodiak (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 Kodiak is also considered by many to be a variant or subspecies of the basic arctic (circumpolar) brown bear.
- In a 1970 National Geographic (Vol 137:4, April 1970) article, "White Tiger in My House", 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 regarded by some taxonomists as a variety of brown bear.
- 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.
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. [link] 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 Service suggested grolar or pizzly, as well as nanulak, an elision of the Inuit nanuk (polar bear) and aklak (grizzly or brown bear). Both grolar and pizzly were used by the Canadian Broadcast Corporation [link] 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 warming progresses and alters normal mating periods. [Dateline Earth Blog, reporter Lisa Stiffler, "You got your grizzly in my polar bear," May 11, 2006] The Canadian Wildlife Service noted that grizzly-polar hybrids born of zoo matings have proven fertile.[link]
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 Nunavut.
Sloth bear hybrids
Hybrids have been produced between the sloth bear (Melursus ursinus) and the Malayan sun bear (Ursus malayanus) at Tama Zoo in Tokyo, and also between the sloth bear (Melursus ursinus) and the Asiatic black bear (Ursus thibetanus, or Selenarctos thibetanus). (Gray, 1972; Asakura, 1969; Scherren, 1907).
See also
References
- Darwin, Charles. "The Variation Of Animals And Plants Under Domestication"
- 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 brownbear and a male polar bear in Lodz Zoo." Przeglad Zoologiczny, 9:313-319. [Polish with English summary.]
- Kowalska, Z. . 1969. "A note on bear hybrids Thalarctos maritimus and Ursus arctos at Lodz zoo." International Zoo Yearbook, 9:89.
- Reed, Elizabeth C. "White Tiger in My House." National Geographic (Vol 137:4, April 1970)
- 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.
- Gray, A.P. 1972: Mammalian Hybrids. A Check-list with Bibliography. 2nd edition.
- Asakura, S. 1969: A note on a bear hybrid, Melursus ursinus x Helarctos malayanus, at Tama Zoo, Tokyo. Int. Zoo Ybk. 9:88.
- Scherren, H.: Some notes on hybrid bears. Proc. Zool. Soc. London 431-435, 1907.
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