If I took a few polar bears, say five, to Antarctica and turned them loose near a colony of Emperor Penguins, which population would survive?
Could the bears change their hibernation for the Southern Hemisphere?
Would they eat all the penguins and then both die out?
That’s an interesting question. The apex predators down there are the killer whale then the leopard seal, for what it’s worth.
there are like 12 million penguins
Assuming 10% population growth per year
feed polar bear 1 penguin a day
it would take like 35-40 years to get to the point of eating 50,000 penguins a year.
thats like 0.04% penguins being turned into bear chow…so food shouldnt be an issue at least at first. 100 years down the line it gets a little messier.
Five polar bears wouldn’t be enough to maintain genetic diversity. Also many would die simply due to being lost, being unfamiliar with their new territory, not knowing where the best food sources are…
I don’t know if bears would be any good at catching penguins either. Penguins are slow on land, but they live near the water.
I’d pay money to see that experiment go live. Well, we could also crowdfund some supercomputer to run couple of simulations about that issue …
Polar bears don’t hibernate. They remain awake and active all throughout the year. In the winter they enter a state called walking hibernation in which they can maintain their body temperature while reducing their metabolic rate and recycling proteins.
Pregnant females will den for up to eight months until they give birth to their cubs. They do not enter true hibernation, however, since they need a high body temperature to nurse their cubs.
These cycles probably would occur during their natural period when it is winter in the Arctic and not sync with the Antarctic winter.
If you follow the sound of Morgan Freeman’s voice you will find some penguin colonies located a considerable distance from the open water. From the open water.
It gets a lot colder in Antarctica than the Arctic, so maybe there is a survivability threshold for winter. Penguins are incredibly oily so may not be good as a dominant food for a top predator that probably eats a range of stuff normally, but the extra fat may help them in the colder months.
It would be a disaster for the penguins.
Antarctic penguins evolved in a world where the dangerous predators live in the water, which also happens to be the place penguins have to go to find their food. Antarctic penguins rest and nest on land because that’s the safe place, even if it gets brutally cold. That’s why the penguins there don’t fear people - they have no instinct to fear other animals on land.
Introducing polar bears means there will be no safe place left for the penguins. They won’t be able to outrun the bears on land, and they don’t/can’t sleep or nest in the water, so they’ll be wiped out.
As for how bears would do - until they render the penguins extinct they’ll probably be fine. Their “natural cycles” will most likely re-tune to antarctic seasons because such things are usually triggered by things like the length of daylight and not actual geographic location. The “greasiness” of penguins probably won’t be a problem given that the normal diet of polar bears are seals - which are also very greasy and oily due to stores of blubber. Also, while polar bears are inclined to be carnivores they are actually, like all bears, omnivores and can subsist quite well in human trash dumps scavenging our dietary remnants so I presume they’d adapt just fine to eating flightless birds.
Once the penguins are all eaten the bears will starve to death. Great. Extinction of multiple species. Not a good idea.
So far everyone has been writing as though the availability of penguins is the only consideration for survival. But what about the climate and the geography? Isn’t it generally a lot colder and a lot more barren in Antarctica than the Arctic? Are the bears going to be sufficiently sheltered from the elements? Also, are there going to be any times of year when penguins aren’t available in sufficient quantity to sustain them, and if so, will there be any other animals or vegetation for them to eat?
I imagine that’s why there are no Arctic Penguins. If any did ever make their way ‘up’ there, they would just be polar bear food. They have got as far North as the Galápagos.
Arctic penguins survived until very recent times (1800s). People killed them off, not polar bears.
Antarctica is not homogeneous, some places are more cold than others. Anything near open water will have somewhat moderated temperatures (otherwise there wouldn’t be open water).
In the north, polar bears will live quick well on barren ice floes, hunting in the sea for food. They don’t require vegetation. As long as there is sea ice they don’t even require land. Barren land is not a problem if they have access to food in/near the sea.
I’m not sure what “shelter” you think is required by animals adapted to swim in polar waters then climb out, soaking wet, and take a nap on a bare ice floe.
Females do require a den for reproduction, but Antarctica does have land, as well as areas of ice/snow where a female can dig out a den - that’s what they do in the north, it should translate just fine to the south.
Penguins are pretty much year round. If penguins are off the menu polar bears aren’t particularly fussy, they’ll happily eat seal (which is most of what they eat up north), fish, people (they have been known to actively stalk/hunt/eat humans), and whatever they can find at trash dumps. They’re pretty resourceful.
Since they are strong swimmers they might start colonizing islands near Antarctica, perhaps getting far enough to start plaguing human settlements in the far south.
Penguins only come ashore in the breeding season. Emperors, for instance, spend half the year out to sea away from Antarctica. Others, even more so.
Seals. No vegetation.
No, they’re not. They spend months at sea. And young adults spend their first few years entirely at sea.
AFAIK they don’t do this year-round, and they certainly don’t do this for their entire life cycle (as you later write).
Yes, but I did specifically ask about access to food. Polar bears in the north do require vegetation (or at least, it’s mighty convenient for them) because there are parts of the year when their seafood is unavailable.
As I mentioned before, I believe that the Antarctic is generally colder than the Arctic. I think that even the warmest parts of Antarctica are still colder, on average, than the coldest parts of the Arctic that polar bears inhabit year-round. So even assuming that polar bears can tolerate the full range of temperatures there, this means that they would have to eat more or conserve more energy (or both). Conserving energy is done by taking shelter from the wind and cold.
Which species? I know that some of them aren’t.
I also thought about seal and fish but I’m not sure if there are any special considerations here. It would be nice if the posters here who helpfully described penguin behaviour could do the same for Antarctic seals and fish. Are the seals and fish down there just as susceptible to polar bear attacks, or does their temperament or their environment make it easier for them to get away?
Neither of these is going to be sustainable for Antarctic bears. There simply aren’t enough people and garbage dumps available on the continent.
Antarctica’s around 800 km away from South America, in case those are the “islands near Antarctica” you were thinking of. I doubt they could swim all that way, though maybe they could hitch a ride partway on some icebergs. (I really have no idea—do icebergs generally float in that direction, and if so, how long would that take? A polar bear can go only a few months without food.)
I did not state they do this for their entire life cycle. I very specifically stated the females have to create dens for birth and their young cubs. Antarctica has actual land, as well as snow and ice piles that could be used for this purpose.
If they can’t get seafood/penguins/seals they sort of screwed in Antarctica proper… but since the entire ecosystem down there runs on sea life (a few teeny tiny plants excepted) I’m guessing there’s available food, but I’m not an expert.
A couple weeks ago Chicago was actually colder than McMurdo base - how cold a part of Antarctica is depends on season and proximity to open water as well as other factors.
Yes, the absolute coldest temperatures ever recorded on the planet were in Antarctica - in the interior in winter, not the coastlines. I suppose hypothetically a bunch of polar bears could attack a colony of emperor penguins nesting in the dead of winter as a survival measure, because the birds, encumbered by holding an egg on their feet to incubate it, are going to be sitting ducks and unable to flee, but would that be too cold for a polar bear or not? I have no idea, but maybe not. I mean, the penguins manage to survive it (albeit with behavioral adaption as much as anything else - they jockey around so no one penguin spends all the time on the outside of the group and everybody gets some benefit from being in the center of the crowd and its cumulative body heat/windbreak effects, something a hunting bear would not be able to use).
Even so - the bears can avoid the worst cold by simply sticking to the coasts which, as long as they can get food there, they’d probably be inclined to do based on their behavior elsewhere.
Emperors are famous as sticking out even the Antarctic winters so there’s penguins of some sort all the time down there.
I haven’t exhaustively researched which penguins migrate away from Antarctica and which don’t, and don’t really care to do so since this isn’t my question. The fact that at least one species really does spend the entire year down there (including reproducing during the winter!) implies that it’s possible there are others always around.
I’m trying to figure out what “temperament or their environment” would work against bears adapted to polar conditions. Currently, the biggest/baddest predators down there seem to be orcas which make a good living. I dunno, maybe a bear/orca war? Maybe the orcas, which hunt cooperatively, might develop a taste for bear and wipe them out? How speculative do you want to get here?
Polar bears regularly go for 150-200 km swims in their native regions, and have been recorded performing 350 km swims. They have been documented remaining in the water for up to 10 days.
Here is a link showing islands near Antarctica As you can see, there is land closer than South America, some of it inhabited, like South Georgia Island.
Antarctica most definitely does shed icebergs, which would float around and around in the southern ocean. Oh, yeah, I’m pretty sure polar bears would wind up traveling around in the south polar region.
Yes, people killed them off, but it seems like the range of the great auk did not have much overlap with that of polar bears. Just some around the southern tip of Greenland. Whether the lack of overlap is due to environmental differences or due to polar bear predation, I don’t know.
It just occurred to me to wonder why polar bears don’t inhabit Europe. Surely it’s not just because of people, since the northern parts of Scandinavia are barely populated. Perhaps some species of penguin could do quite well in Europe.
A 2011 thread on the same topic: How would polar bears fare in the antarctic? - Factual Questions - Straight Dope Message Board
They do. Just not the mainland.
It’s probably because the native brown bears have some sort of competitive advantage.
