Polar/grizzly bear hybridisation

[STYRBJORN]

Interesting article in the Indy - one of the more sensible papers - today. The shrinking Arctic ice cap, and the earlier shrinkage of the ice cover, mean that Grizzly bears and Polar bears are in contact during the mating season. Hybrid individuals are increasingly common. Over 20 first generation hybrids have been identified so far. More worryingly, at least one 2nd generation hybrid has been confirmed by genetic tests as having been the offspring of a pure male grizzly and a female polar/grizzly cross. This individual exhibited typical polar bear hunting behaviour but it couldn't swim!

So much for hybridisation increasing bio-diversity. Neither grizzly nor polar bear seems likely to survive as a species.

[faz]

there was a program on this subject on nat geo wild a yank shot a polar bear ? so he thought went to court it was a grizz/ polar he got off with the charge it was the first species of these bears

[STYRBJORN]

Was he related to Sarah Palin? A-a-ar-gh! I shoot, for the pot and pest control but there is a limit!

[eeyore]

Originally Posted by STYRBJORN

Was he related to Sarah Palin? A-a-ar-gh! I shoot, for the pot and pest control but there is a limit!

yes, you'd need a damn big pot to cook a polar bear

[turkeyneck]

All this cross breeding between species it won't be long before the hippocrocadillopig makes an appearance

Is a serious concern though and reminds me of our very own Wild Cats. I'm sure this cross breeding must go on with several species detected and undetected.

[RKB]

Originally Posted by eeyore

yes, you'd need a damn big pot to cook a polar bear

Americans do eat Black Bears (there is an open season), and I imagine they eat the Brown Bears too.

Quite a lot of species have a hybrid zone - Collared/Pied Flycatcher, Black-capped/Carolina Chickadees, Carrion/Hooded Crow, various gulls, so hybridisation isn't necessarily much to be worried about. Brown Bears and Polar Bears can only both survive in a narrow contact zone - the Polars can't go further south and the Brows can't live on the ice, so as long as there is a separate habitat then there'll be separate species.

If the hybrids can't swim then they are also less likely to survive, so will be out-competed by pure Polars or Browns. If it really comes down to it, then Polars will be re-absorbed into the Borwn Bear species from whence they originated in the first place. Next time there's an ice age then something similar will no doubt appear again.

[The Woodman]

[quote=turkeyneck;714371]All this cross breeding between species it won't be long before the hippocrocadillopig makes an appearance /QUOTE]

It's already happening!

[STYRBJORN]

[quote=RKB;714373]

Brown Bears and Polar Bears can only both survive in a narrow contact zone - the Polars can't go further south and the Brows can't live on the ice, so as long as there is a separate habitat then there'll be separate species.

That was a major point in the article I read. At current rates of melting the Arctic ice cap will disappear completely in Summer, and the Polar bears will disappear with it. Given the small population of Polar bears, they will be the ones to be absorbed into the larger Brown population.
Seals are hybridising, as are Rorqual whales. A manatee/narwhal cross has also been identified. The danger is that the loss of genetic diversity involved in species extinction lessens the ability of the genus or family to cope with change.

[RKB]

Originally Posted by STYRBJORN

A manatee/narwhal cross has also been identified.

Details please!

[STYRBJORN]

I cannot give details, much tho I would like to be able so to do. Refer to the Indy article, which seemed well referenced.