Polar bears stand a better chance of survival if their 'pizzly' offspring – from mating with a grizzly bear – is culled, scientists say.
Credit: Wikipedia
PARIS: Climate change is pushing Arctic mammals to mate with cousin species, in a trend that could be pushing the polar bear and other iconic animals towards extinction unless their offspring is culled, biologists said.
"Rapidly melting Arctic sea ice imperils species through interbreeding as well as through habitat loss," they said in a commentary appearing in the British science journal Nature.
"As more isolated populations and species come into contact, they will mate, hybrids will form, and rare species are likely to go extinct."
Pizzly: half-polar, half-grizzly bear
In 2006, they said, scientists were startled to discover a 'pizzly' or a hybrid of a grizzly bear (Ursus arctos horribilis) and a polar bear (Ursus maritimus), and in 2010, another bear shot dead by a hunter also was found to have mixed DNA.
Global warming has hit the Arctic region two or three times harder than other parts of the planet, redesigning the environment in which dozens of terrestrial and marine mammals live.
In particular, the shrinking of the Arctic ice cap - set to disappear in summer by century's end without a deep cut in greenhouse gas emissions - has pushed polar bears outside their normal hunting grounds.
Whales, porpoises, seals all have hybrids
The fierce predators use the edge of the ice cap as a staging area to stalk seals, their preferred food.
How far Arctic species have intermingled is unclear, although some important examples abound, according to the article, lead-authored by Brendan Kelly of the U.S. National Oceanic and Atmospheric Administration (NOAA).
Last year what appeared to be cross between a bowhead and a right whale was photographed in the Bering Sea between Alaska and Russia.
There are fewer than 200 North Pacific right whales left, and the far more numerous bowhead could, through interbreeding, quickly push this remnant population to extinction, the researchers warned.
Different species of Arctic porpoises and seals are also known to have produced offspring with a mixed bag of chromosomes.
pizzlies
I personally, think that everyone who has a running car/truck should be able to go into a dealer ship and trade in their vehicle for a hybrid no if and or buts about it. This alone would help with all of this global warming. Its up to the WORLD to fix this problem, And as far as the pizzlies...... If it was bread into them can it not be breed out of them as well? I think bred them like crazy to keep the polar bear and the grizzly alive and keep count of all of them then once a good healthy number has arrived start breeding it out so a hybrid would mate with a pure breed and right their its half gone! breed it 2-3 times and youve got a 98% polar bear/ grizzly again and keep the breeding constant so in 20 years the polar bear is again a polar bear. but thats my thinking about it. Its no longer about what we "morally"should do, its come down to either mix breed to keep the animals alive or loose them forever. Or as I said in the beggining it starts with high emmission vehicles and so forth. Trevor
orly?
Pizzlies?
Now I can make room in my bookmarks for a more worthy read.
I won't even bother to make an argument here.
Buh-Bye Cosmos.
Bears Interbreeding
Sorry, but the author needs to do some more research. Interbreeding between polar bears and grizzlys has always taken place. It has nothing to do with the natural climate changes that have always taken place on this planet, whether it's warming or cooling. These bears will probably survive long after humans are extinct.
nature
Now we want to interfere with surely what must be natural survivial tactics, probably inacted many times previously. Leave it.
Totally agree...
How do we know that DNA mixing is not on the master plan for survival... who are we to say "Offspring's should be culled" leave mother nature alone for once!!
True that!
It is illogical to kill the hybrid offspring. More will be born, and it is unfair of us to kill the hybrids. And besides, this has happened before no matter our human activities. I agree that we can cross-breed them multiply until we breed out the grizzly genes, but to kill the hybrids is cruel. If we wish to both keep the polar bears alive all we have to do is "cull" our own use of fossil fuels. We are running out of oil anyways, and need to find an alternative energy source.
Pizzlies
Although pizzlies may not be the best adaptation to the ever progressing conditions caused by man they are nevertheless an example of evolution. Who knows what the end result may be. The pizzlies could well be an intermediate step in adaptation and their culling would interrupt this.
Perhaps one day our world goverments may pay heed to global warming and stop making it worse. Do we have no thought for our grandchildren. Must we always live for today and dismiss the effects of our behaviour upon future generations.
I read recently an article I wrote in 1974 which mentions global warming. If 36 years later the situation is still worsening I despair for the future of mankind let alone pizzlies.
No; I am not in favour of culling these creatures. In fact; culling homo sapiens is more necessary.
Martin Taylor
WriterSP
DUH!??? Yes, let's cull the offspring so that when the species goes extinct, it will have been "pure". What kind of idiot thinks this way? Leave those polar bears the f#*& alone! It is most likely nature's last ditch effort to pass on whatever polar bear DNA can be saved before they're isn't any left at all.
No faith in evolution, eh?
If the 'pizzly' is so badly adapted to swimming but has the instincts to fish, I doubt very many culls would be necessary. Or might it play out differently? Nah, just kill 'em, a fool could see where this will lead, right?
Arrogance, in pure form.
At what point do you stop - hey, bring back the dodo bird through genetic engineering, or any other number of failed species we have watched go under. I know one thing - we're pretty good at that 'preemptive strike' thing. It always works out well, and recent history certainly bears that out.
I seriously doubt that we have a good enough understanding of nature to say whether those animals should be culled, or whether or not the Polar Bear's time on earth has simply passed; how would such a thing be ascertained? There were perhaps billions of types of life forms that lived and died on this planet with zero human influence (every one that went extinct before there were hominids, for example); they had a time here, then they died out. We're so sure that we have this whole 'nature' thing sussed out that we know that the Polar Bear should be here, and not be becoming another species, adapting to the coming changes, or simply ceasing to be? Should it be denied the fate of the other species because we find it attractive to look at?
Whoever suggested the whole 'everyone gets a hybrid!' thing doesn't even know very much about cars, much less environmental economics, much less enough to make sweeping decisions to affect this planet's future. I can't say that those who are suggesting to kill these animals are exhibiting less insight than this random commenter, though.
At best, one can honestly say "I don't know." More likely you'll get the arrogance of hairless monkeys, barely out of the jungle, who vainly pretend to the be the masters of this planet and controllers of it's destiny.
So we play God now....
We are so damned stupid really.... Global Warming is in fashion and its in fashion to think its manmade so lets now destroy anything that is created by global warming whether or not we have proof or not. Species will come an go in the history of the earth like they have always done but lets not play God and think we know what is best for the planet. I agree we need to look after what we have and have altered the world around us in a negative way but hasnt any dominant species done that since day dot.... Humankind needs a wake up call and needs to realise our history on earth is and will be brief and we dont in fact know everything about the world around us and never will and it is arrogant to think otherwise..... We need to stop playing God