An ursid hybrid is an animal with parents from two different species or
subspecies of the Ursidae 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. Note all of the confirmed hybrids listed here
have been in captivity, but there are unconfirmed reports of hybrids in the
wild. A recent study by Kutschera and
colleagues found genetic evidence of multiple instances and species
combinations where genetic material has passed the species boundary in bears.
Specifically, species with evidence of past intermingling were brown bear &
American black bear, brown bear and polar bear, American black bear and
Asian black bear, bears currently distributed in Asia. Overall, this study
shows that evolution in the bear family has not been strictly bifurcating, but
instead showed complex evolutionary relationships.
Brown bear/American 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,...
Intercontinental brown bear hybrids Hybrids between the European brown bear
and the grizzly bear 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. All the Ursinae species appear
able to crossbreed. = 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 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 bear at the U.S. National Zoo,
resulting in three hybrid offspring. One hybrid was named Willy Wonka 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 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 Territories. 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, as well as 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 Service suggested grolar or pizzly, as well as nanulak, an
elision of the Inuit nanuk and aklak. 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 warming
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 Nunavut.
Asiatic black bear hybrids In 1975, within Venezuela's "Las
Delicias" Zoo, a female Asian black bear shared its enclosure with a spectacled
bear, and produced several hybrid descendants.
In 2005, a possible black bear/sun bear hybrid cub was captured in the Mekong
River watershed of eastern Cambodia. The hybrid's mane was relatively slight,
forming a crest on each side of the neck, as is typical in sun bears and
some black bears. The appearance of its face was intermediate between that of
the sun bear and the black bear, though its ears and large stout canines closely
resembled those of the sun bear. Overall, the hybrid resembled an Asiatic
black bear with an unusually glossy pelage and an unusual head.
In 2010, a male hybrid between an Asiatic black bear and a brown bear
named Emma was taken from a bile farm and into the Animals Asia Foundation's
China Moon Bear Rescue Sloth bear hybrids
Hybrids have been produced between the sloth bear and the Malayan sun bear at
Tama Zoo in Tokyo, and also between the sloth bear and the Asiatic black bear.
See also Bear
References 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." 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.] Kowalska, Z.. "A note on bear hybrids
Thalarctos maritimus x Ursus arctos at Łódź zoo". International Zoo Yearbook 9:
89. doi:10.1111/j.1748-1090.1969.tb02632.x.
Wurster-Hill, D.H. and Bush, M. 1980: The interrelationship of chromosome
banding patterns in the giant panda, hybrid bear, and other carnivores.
Cytogenet. Cell Genet. 27:147-154. Talbot, S.L; Shields, G.F..
"Phylogeography of Brown Bears of Alaska and Paraphyly within the Ursidae".
Molecular Phylogenetics and Evolution 5: 477–494. doi:10.1006/mpev.1996.0044.
PMID 8744762.