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polar bear going extinct. relocate to antartica with penuins





Lennon
why not.
polar bears would flourish with all the penguins in antarctica along the peninsula near south america, where there's enough penguins in number to survive....
http://www.wired.com/science/planetearth/news/2008/07/species_relocation
http://mustelid.blogspot.com/2005/01/polar-bears-in-antarctica.html
more importantly this link
http://www.polarbearsinternational.org/polar-bears/what-the-experts-say/expert-q-and-a/antarctica
thoughts Question
watersoul
I think the 3rd link you provided pretty much summed up the argument against quite well Lennon Smile
Ankhanu
Yep, classically bad idea.
ocalhoun
... Until several species of antarctic penguin are on the verge of extinction because the invasive species is eating them all...

When has introducing a new species to an environment ever turned out well?
Ankhanu
That's the major concern... well, not that penguins are decimated (though it is a concern), but just the general imbalance that introducing a major predator into the ecosystems would cause.

Really, though, polar bears would be terribly suited to feeding on penguins... unless they decimated something like an inland breeding colony or something, but that's a fairly limited opportunity. Penguins are fast and agile; polar bears? Less so.
Chances are they'd attempt something resembling their natural foods; seals. Their populations are kept in check by other factors in the antarctic; adding another predator to the mix would stress the seal populations, which would imbalance the penguins, various fish, krill, sharks, whales, etc.

In short, if they managed to survive at all in the antarctic, it would have terrible consequences. If they didn't well, they'd be being sent to a death sentence. Brilliant.

Saving one species of charismatic megafauna is not worth potentially imbalancing an entire ecosystem.
Lennon
but say you specified a remote part of antarctica for polar bears, where the majority of penguins and seals would survive intact given their distance from the few polar bears. Even well into the future, given the penguins are given long enough to adapt from the distance to the main polar bear colony, it could be designed in such a way to give penguins and seals a chance for example. or relocating some penguins/seals to another remote part of antarctic coastline.
ocalhoun
Ankhanu wrote:
Penguins are fast and agile; polar bears? Less so.

Penguins don't seem very fast and agile when waddling around on land... and especially not when incubating eggs...

*not a penguin expert

Lennon wrote:
but say you specified a remote part of antarctica for polar bears,

The remote parts of Antarctica are uninhabitable even for polar bears. Simply too cold, too windy, and nothing at all to eat.
Quote:
where the majority of penguins and seals would survive intact given their distance from the few polar bears. Even well into the future, given the penguins are given long enough to adapt from the distance to the main polar bear colony, it could be designed in such a way to give penguins and seals a chance for example. or relocating some penguins/seals to another remote part of antarctic coastline.

It only takes a few individuals being released to cause a wide-spread invasive species problem...
Granted, it would take a while since polar bears are slow breeders, but it would still be pretty much irreversible.
We have a hard enough time combating invasive species in temperate climates; hunting down all the (hypothetical) polar bears in Antarctica would be nearly impossible.


Quite simply, the opportunity of saving one species from extinction is not worth risking an entire ecosystem for.


A better solution, should things get that desperate, would be to keep polar bears in zoos and/or preserves, wait until conditions are better again, and re-introduce them to their native habitat.
Reintroducing a species into the wild has gone well in the past sometimes.
Ankhanu
Lennon wrote:
but say you specified a remote part of antarctica for polar bears, where the majority of penguins and seals would survive intact given their distance from the few polar bears. Even well into the future, given the penguins are given long enough to adapt from the distance to the main polar bear colony, it could be designed in such a way to give penguins and seals a chance for example. or relocating some penguins/seals to another remote part of antarctic coastline.


There are a few problems here, some of which ocalhoun pointed out. No food for the bears, the bears die. Let the bears at the food supply and it upsets the whole ecosystem.

The thing with adaptation is that there needs to be selective pressure to drive it. That means, the bears have to be there predating the targets. That means that the penguins and seals have to develop traits to help them survive against the bears, and enough of those survivors need to successfully breed to instate that trait within the population, over several generations. Meanwhile, the bears are undergoing selective pressures to overcome these developing traits in the prey...

Populating the bears in a "remote location" where they won't impact the penguins and seals means they won't have food... also, bears being very capable walkers, runners and swimmers, are apt to move around until they find a food source... they'd have to be fenced in at this remote location and fed by people.

I do believe, however, that it would be relatively easy to extirpate invasive polar bears from Antarctica if it came down to it. It wouldn't take much to at least make them rare enough that the population becomes unviable. You don't have to kill all of them, just enough of them Wink


ocalhoun wrote:
Ankhanu wrote:
Penguins are fast and agile; polar bears? Less so.

Penguins don't seem very fast and agile when waddling around on land... and especially not when incubating eggs...

*not a penguin expert


Not paticularly, no...
While incubating, they'd be... um... sitting ducks Razz
When on land they would be vulnerable, but they can slide like an SOB, and turn on a dime. Polar bears would have to ambush them (which is a behaviour they're good at) to be really successful.
Once they hit the water though, it would be game over.

ocalhoun wrote:
A better solution, should things get that desperate, would be to keep polar bears in zoos and/or preserves, wait until conditions are better again, and re-introduce them to their native habitat.
Reintroducing a species into the wild has gone well in the past sometimes.


The problem with reintroducing polar bears to their natural habitat is the same problem currently faced: their natural habitat is changing/disappearing. As the arctic warms, the sea ice they rely on for habitat and hunting grounds are either not forming, or are not strong enough and lack the longevity needed for the polar bears to exploit them.
Given that the problem is climactic, waiting until conditions get better is a VERY long term solution... and by that point, the arctic community would likely be adapted to one that excluded bears.
lovescience
http://www.youtube.com/watch?v=taNTnxtgWTc

The bear needs sea ice, its where the bear catch seal.

Is it possible for people to make several floated zoo there where can keep some sea ice and attract seals and polar bears?
jwellsy
The Polar Bear population is increasing.
http://www.examiner.com/seminole-county-environmental-news-in-orlando/canada-s-growing-polar-bear-population-becoming-a-problem-locals-say

http://www.telegraph.co.uk/comment/columnists/christopherbooker/5664069/Polar-bear-expert-barred-by-global-warmists.html
Ankhanu
jwellsy wrote:
The Polar Bear population is increasing.
http://www.examiner.com/seminole-county-environmental-news-in-orlando/canada-s-growing-polar-bear-population-becoming-a-problem-locals-say

http://www.telegraph.co.uk/comment/columnists/christopherbooker/5664069/Polar-bear-expert-barred-by-global-warmists.html


I'm skeptical Wink

First, The Examiner has been known to publish material that hasn't been well researched, even occasionally flat out fictitious. It's also a pro-am publication source, with both professional and amateur contributors... there is a difference in info quality to be expected. Second, looking at the author's, Kirk Myers, contributions, he has a clear reporting agenda. The article should be read with that in mind (and his writing style clearly brings this across, hence me looking at his info).

The Telegraph isn't a bad source; one of the biggest (perhaps the biggest) print papers in the UK. The paper does have a mild conservative leaning, however.

My immediate thought concerning the apparent increase in polar bear numbers is that it is likely illusory. I've encountered these sorts of illusions where people believe that populations of a species (usually a predator) is high or low based on encounter rate, but the populations are not changing, or are even in decline, but the animals have moved into areas where they encounter people more often. Where I live/work now (I work in a national park), people are encountering more bobcat and lynx than normal. The populations of these cats hasn't increased, just encounter rate. It's a low population year for snowshoe hare and, it seems red squirrel as well; two species these cats rely on for food. As such, the cats are roaming into areas they normally avoid, like local villages, where they encounter people more often. This can give the illusion that their populations have increased, because it seems like there are more.
My immediate thought is, "yeah, there are more polar bears being seen by people, but where did they come from?" Are there fewer bears in more traditional habitats further away from settlements?

I did start a quick search of some primary literature on the subject, rather than rely upon popular media, which often reports ecological stories rather poorly... I haven't found the answer to the questions on the validity of your news articles and my question on population densities yet, but I also stopped after only a couple journal articles to write this Wink
I have found, however, a few papers (primarily written by Dr. Ian Sterling from the Canadian Wildlife Service, and coauthors) looking at long term population and sea ice trends in Hudson's Bay along the coast of Manitoba and Ontario (not as far north as Nunavut generally) that show clear trends to reduced sea ice, earlier breakup (not significantl so along the Ontario coast) and reduced condition of bears through the past 30+ years. Even if populations are not declining (and some clearly are), the loss of physical condition will lead to reduced reproductive success.

I'll keep looking later when I have more time to dedicate to a literature search.

EDIT - I can't help myself when I start in on a journal search Razz I always see that one title that keeps me from closing out the window Wink Here's the abstract from a paper that seems to be pertinent (I didn't log in to my university account to check on the availability of the journal to me yet... the full content of the article may change my impression Razz )

Abstract - Effects of Earlier Sea Ice Breakup on Survival and Population Size of Polar Bears in Western Hudson Bay wrote:
Some of the most pronounced ecological responses to climatic warming are expected to occur in polar marine regions, where temperature increases have been the greatest and sea ice provides a sensitive mechanism by which climatic conditions affect sympagic (i.e., with ice) species. Population-level effects of climatic change, however, remain difficult to quantify. We used a flexible extension of Cormack–Jolly–Seber capture–recapture models to estimate population size and survival for polar bears (Ursus maritimus), one of the most ice-dependent of Arctic marine mammals. We analyzed data for polar bears captured from 1984 to 2004 along the western coast of Hudson Bay and in the community of Churchill, Manitoba, Canada. The Western Hudson Bay polar bear population declined from 1,194 (95% CI = 1,020–1,368) in 1987 to 935 (95% CI = 794–1,076) in 2004. Total apparent survival of prime-adult polar bears (5–19 yr) was stable for females (0.93; 95% CI = 0.91–0.94) and males (0.90; 95% CI = 0.88–0.91). Survival of juvenile, subadult, and senescent-adult polar bears was correlated with spring sea ice breakup date, which was variable among years and occurred approximately 3 weeks earlier in 2004 than in 1984. We propose that this correlation provides evidence for a causal association between earlier sea ice breakup (due to climatic warming) and decreased polar bear survival. It may also explain why Churchill, like other communities along the western coast of Hudson Bay, has experienced an increase in human–polar bear interactions in recent years. Earlier sea ice breakup may have resulted in a larger number of nutritionally stressed polar bears, which are encroaching on human habitations in search of supplemental food. Because western Hudson Bay is near the southern limit of the species' range, our findings may foreshadow the demographic responses and management challenges that more northerly polar bear populations will experience if climatic warming in the Arctic continues as projected.

Regehr, E.V, Lunn, N.J., Amstrup, S.C. and Stirling, I. 2007. Effects of earlier sea ice breakup on survival and population size of polar bears in Western Hudson Bay. Journal of Wildlife Management 71(Cool:2673-2683
Bikerman
I can offer some secondary info (not as good as the primary literature, I would be the first to admit).
Quote:
At the 2009 meeting of the PBSG, the world's leading polar bear scientists reported that of the 19 subpopulations of polar bears, eight were declining, three were stable, and one was increasing. They lacked sufficient data to say what is happening to the remaining seven.

http://www.polarbearsinternational.org/polar-bears/faq#q2
stressball
would love to join them.
ocalhoun
stressball wrote:
would love to join them.

The polar bears or the penguins?
inoshi
Lennon wrote:
why not.
polar bears would flourish with all the penguins in antarctica along the peninsula near south america, where there's enough penguins in number to survive....
http://www.wired.com/science/planetearth/news/2008/07/species_relocation
http://mustelid.blogspot.com/2005/01/polar-bears-in-antarctica.html
more importantly this link
http://www.polarbearsinternational.org/polar-bears/what-the-experts-say/expert-q-and-a/antarctica
thoughts Question

I saw an article that reported polar and grizzly bears were cross-breeding, creating a hybrid.
ocalhoun
inoshi wrote:

I saw an article that reported polar and grizzly bears were cross-breeding, creating a hybrid.

This is nothing new, and (rarely) happens whenever grizzly and polar bear habitats overlap.

The result is called a grolar bear, and apparently they're much feared because they're nearly as big as a polar bear, but more aggressive than either ancestor.
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