Study: Polar bears may survive ice melt, with or without seals

New calculations indicate that land-based food sources like caribou, snow geese, and eggs might provide enough calories for bears to avoid starvation

Two polar bears were photographed near the coast of the Western Hudson Bay, where researchers have shown bears are consuming land-based foods during ice-free periods. CREDIT © AMNH/R. Rockwell
Two polar bears were photographed near the coast of the Western Hudson Bay, where researchers have shown bears are consuming land-based foods during ice-free periods. CREDIT © AMNH/R. Rockwell

From the AMERICAN MUSEUM OF NATURAL HISTORY

As climate change accelerates ice melt in the Arctic, polar bears may find caribou and snow geese replacing seals as an important food source, shows a recent study published in the journal PLOS ONE. The research, by Linda Gormezano and Robert Rockwell at the American Museum of Natural History, is based on new computations incorporating caloric energy from terrestrial food sources and indicates that the bears’ extended stays on land may not be as grim as previously suggested.

“Polar bears are opportunists and have been documented consuming various types and combinations of land-based food since the earliest natural history records,” said Rockwell, a research associate in the Museum’s Department of Ornithology who has been studying the Arctic ecology of the Western Hudson Bay for nearly 50 years. “Analysis of polar bear scats and first-hand observations have shown us that subadult polar bears, family groups, and even some adult males are already eating plants and animals during the ice-free period.”

Previous studies have predicted mass polar bear starvation by 2068, when annual ice breakup is expected to separate the bears from their sea-ice hunting grounds for a consecutive 180 days each year–creating ice-free seasons that will last two months longer than those in the 1980s. But those estimates assumed no energetic input from land food sources.

Gormezano and Rockwell computed the energy required to offset any increased starvation and then determined the caloric value of snow geese, their eggs, and caribou that live near the coast of the Western Hudson Bay. They found that there likely are more than enough calories available on land to feed hungry polar bears during the lengthening ice-free seasons.

Although the exact energetic cost for a bear to hunt geese and caribou is uncertain, polar bears in Manitoba have been reported ambushing caribou with the same energetically low-cost techniques they typically use to hunt seals. The similar size of these two prey species means that bears would need to hunt for caribou only as often as they would usually hunt for seals, the researchers say.

“If caribou herds continue to forage near the coast of Western Hudson Bay when bears come to shore earlier each year, they are likely to become a crucial component of the bears’ summertime diet,” Rockwell said.

The eggs of snow geese are another food source for bears, and the energetic cost of obtaining eggs in ground nests is exceedingly low, the researchers say. With adequate food sources available, snow geese are known to endure polar bear egg predation without detrimental effects to the population.

Scientific consensus holds that the rapidly melting circumpolar ice reserves will increasingly prevent polar bears from hunting the seals on which they currently depend. Nevertheless, these observations of one population along the Western Hudson Bay show that bears marooned on land might, where the conditions are right, stave off starvation by turning to alternate food sources.

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Ben
September 7, 2015 7:44 pm

It’s better than they thought.

george e. smith
Reply to  Ben
September 8, 2015 10:18 am

So where are the seals going when there is less, or no ice ??
Would they prefer the land or the water. Seems like the bears can get them in either place; perhaps easier on land when they are having their pups.
How do the polar bear’s close cousin, the brown bear survive without ice ??

Walter Sobchak
Reply to  george e. smith
September 8, 2015 8:10 pm

Seals are air breathers. If there is no ice they must surface. If they surface the bears can eat them.

Samuel C. Cogar
Reply to  george e. smith
September 9, 2015 6:19 am

If all the sea ice melts …… and the Polar Bears can’t find something to eat on the shores of the Arctic Ocean, etc., during the seal “birthing” season ……. then they are deserving of starving to death
To wit:
http://cdn2.arkive.org/media/CD/CDB9E2EA-366F-4D46-A2FE-7AB9071708F1/Presentation.Large/Male-southern-elephant-seals-harems-of-females-in-beach-colony.jpg

noaaprogrammer
September 7, 2015 7:48 pm

Another back-pedaling article.

Alan Robertson
September 7, 2015 7:51 pm

“As climate change accelerates ice melt in the Arctic…”
—————
Prove it.

Mark luhman
Reply to  Alan Robertson
September 7, 2015 7:56 pm

Actually the question is what melting?

george e. smith
Reply to  Mark luhman
September 8, 2015 10:20 am

How much of that ” ice melt ” is actually Russian ice breakers running around breaking up the artic ocean ice into smaller pieces with more perimeter in contact with the ocean; so faster melting ??

Reply to  Alan Robertson
September 7, 2015 8:01 pm

As If climate change accelerates ice melt in the Arctic…

Gunga Din
Reply to  verdeviewer
September 7, 2015 8:10 pm

IF Man has much do with the “As” or the “If”.
(I know. “The science is settled”. That’s why it keeps changing.)

Mike
Reply to  Alan Robertson
September 7, 2015 11:52 pm

Nevertheless, these observations of one population along the Western Hudson Bay show that bears marooned on land might, where the conditions are right, stave off starvation by turning to alternate food sources.

Who would have thought that a hungry animal would be able to eat something other that it main prey if that prey becomes less abundant? Sadly this needed to be said in this age of alarmist pseudo-science. Well at least they are looking at observations and trying to bring some sense to the fate of our lovely fluffy, cuddly polar bears.

As climate change accelerates ice melt in the Arctic

Since neither the press release ( which this appears to be ) nor our host provide a link to the paper being announced it is unclear whether the paper contained any such stupidly false claims. I suspect not.
In any case arctic sea ice melting stopped accelerating sometime around the release of AR4 in 2007 !!
https://climategrog.wordpress.com/2013/09/16/on-identifying-inter-decadal-variation-in-nh-sea-ice/

Mike
Reply to  Mike
September 7, 2015 11:53 pm

forgot the graph:comment image

Chris
Reply to  Alan Robertson
September 8, 2015 6:54 am
Marcus
September 7, 2015 7:54 pm

Wouldn’t the seals also follow the shoreline IF it shrinks , or do they have one specific area of ocean that they stay within ????

September 7, 2015 8:03 pm

That picture is about the fattest polar bear I’ve ever seen.

AndyG55
Reply to  ATheoK
September 7, 2015 8:44 pm

Thin and emaciated !! NOT !! 🙂
How many climate scientist to get that rotund !!!

David Chappell
Reply to  AndyG55
September 7, 2015 9:37 pm

Well, perhaps not physically, but I’d bet their bank balances do.

AndyG55
Reply to  AndyG55
September 7, 2015 9:40 pm

I meant… how many climate scientists did they eat, to get that rotund. 🙂

Chris
Reply to  AndyG55
September 8, 2015 6:55 am

“Well, perhaps not physically, but I’d bet their bank balances do.”
Ah yes, the always conjectured but never proven rich scientists.

Gary Pearse
Reply to  AndyG55
September 8, 2015 9:34 am

Clime Scientists are probably too rich a diet.

dp
Reply to  ATheoK
September 7, 2015 10:36 pm

She is with child.

Reply to  dp
September 8, 2015 10:13 am

Polar bears birth their young during hibernation during the cold winter and newborn polar bears are born tiny.
No bear in summer or fall (soft sand/mud iceless water’s edge) would show that much pregnancy.

CarlF
September 7, 2015 8:16 pm

They apparently just discovered that Polar Bears are scavengers and omnivores?

Brent Hargreaves
Reply to  CarlF
September 7, 2015 8:43 pm

Omnivores: who knew??? Next paper: “Risk of Polar Bears getting Hypothermia Mitigated by Insulation”, research suggests. Said Professor Greenback, lead author of the multinational team of fifty scientific brainboxes: “It’s, like, amazing. They have this stuff we have decided to dub ‘white fur’ and it seems to reduce heat losses. With further research funding we may be able to prove this principle. This has implications for mankind: plumbers might, for example, clad water pipes in white fur.” It is hoped that the Nobel Prize committee is aware of this groundbreaking work.

old construction worker
September 7, 2015 8:19 pm

What, Polar bears can’t swim?

mebbe
September 7, 2015 8:40 pm

Apparently, the snow-geese are going to be just fine,too.
” With adequate food sources available, snow geese are known to endure polar bear egg predation without detrimental effects to the population.”
I’m a bit concerned about the vegetation, though; the bears in the pic seem to have seriously over-grazed their broccoli patch.

roger
Reply to  mebbe
September 8, 2015 1:36 am

consider also Svarlbard, where, we were told some years ago, Barnacle geese numbers had increased after decades of protection to the point that they had swamped suitable nesting areas.
I seem to remember reports of polar bears eating young and eggs there in the past, having found the supply of young etonian climate change students too irregular to become a staple part of their omnivore diet.

Gary Pearse
Reply to  roger
September 8, 2015 9:36 am

They waxed hopeful when the arctic was invaded by sailboats, rowboats and cross ice adventurers going out to see how the bears were doing.

Hoyt Clagwell
September 7, 2015 8:58 pm

Isn’t it interesting that the greenies always want to save a species, but only so another species can kill them. The delta smelt need to be saved to feed the salmon, frogs need to be saved to feed the birds, and baby seals can’t be clubbed because they need to be ripped apart, by tooth and claw, alive, to feed polar bears. How compassionate those greenies are.

Auto
Reply to  Hoyt Clagwell
September 8, 2015 12:42 pm

hoyt
The watermelons seem to wish to eliminate any possibility of a further supply of young Etonians (even Winston Churchill only went to Harrow), by stopping anyone but their watermelon elite giving their kids an advantage.
And Eton is an advantage.
Auto

dp
September 7, 2015 9:04 pm

This is not their first rodeo. Polar bears have survived all the climate changes since there were polar bears which is over 100,000 years, and nothing about the current climate is unique in any way. That time frame, by the way, means there was a time when there were no polar bears. The fact that they are still here makes their ability to survive change self evident. Their numbers are still growing. Only climate scientists don’t get that. They are highly mobile opportunists that will eat anything on the menu. I put this right up there with exposed tree stumps at the snout of retreating glaciers as evidence of serial climate scientist ignorance. One could conclude they never personally do field work, preferring to write bad models for data witnessed first hand by others.

commieBob
Reply to  dp
September 8, 2015 6:04 am

… One could conclude they never personally do field work, preferring to write bad models for data witnessed first hand by others.

One of the most prominent worriers-about-polar-bears-and-global-warming is Ian Stirling. I’ve met him in the field on several occasions. He’s done lots of field work. As far as I can tell, he is a first rate scientist. wiki He will tell you that polar bears eat seals and how they hunt them. He thus extrapolates that, if the ice melts due to global warming they won’t be able to get seals and will thus starve.
Dr. Stirling knows what he knows. However, he has no experience with prolonged periods of warming. We have had a warmer climate in the arctic during the Bronze Age, Roman, and Medieval warm periods. The ice conditions were probably quite different. In fact, the Vikings may have circumnavigated Greenland. link
It’s quite possible to do lots of field work (and be an acknowledged expert) and still be wrong. The problem arises when people extrapolate beyond what they actually know.

dp
Reply to  commieBob
September 8, 2015 2:12 pm

Does he know where the seals are going to go when there’s no pack ice? Seems like they’re going to have to hit the beach where a lot of hungry polar bears are hanging out with their brown bear cousins or learn to look like orcas.

Walter Sobchak
Reply to  dp
September 8, 2015 9:00 pm

“Polar bears have survived all the climate changes since there were polar bears which is over 100,000 years”
From our friend Dr. Susan J. Crockford at polarbearscience.com:
“Estimates of when polar bears began to split from brown bears continue to change as geneticists look further into the polar bear genome. Recent studies suggest that polar bears split from a common brown bear ancestor 350,000-6 million years ago.” –http://www.polarbearsinternational.org/about-polar-bears/essentials/evolution
“Estimates of polar bear age over the last 4 years (there were also some before that), counting down from the most recent:
8. Liu et al. 2014 < 500 thousand years ago [this post]
7. Cronin et al. 2014 1.2 million years ago
6. Cahill et al. 2013 ~600 thousand years ago (“similar to Hailer et al. 2012”)
5. Miller et al. 2012 ~4-5 milliion years ago
4. Hailer et al. 2012 ~600 thousand years ago
3. Davison et al. 2011 ~160 thousand years ago
2. Edwards et al. 2011 ~120 thousand years ago
1. Lindqvist et al. 2010 ~134 thousand years ago
http://polarbearscience.com/2014/05/10/evolution-by-geneticsts-again-yet-another-date-for-when-polar-bears-arose/
Note that the more recent studies have much longer spans the earlier ones. By way of contrast, "Over the past 740,000 years there have been eight glacial cycles."
wikipedia.org Quaternary_glaciation
The previous interglacial the Eemian began about 130,000 years ago and ended about 115,000 years ago, and was warmer than anything so far observed in the Holocene. wikipedia.org Eemian
The most reasonable inference is that the current inter glacial is not the Polar Bears first rodeo.

September 7, 2015 9:08 pm

caribou, snow geese, eggs and humans…

dp
Reply to  J. Philip Peterson
September 7, 2015 9:27 pm

We should relocate a few (neutered) dozen of the many thousands of them to the Florida Everglades where they can kill off the infestation of anaconda and boa constrictors there. When the snakes run out of gators and birds to feed on they’re going to start crawling into boats, homes, and cabins to make snacks of people. Bears are too big to eat and big enough to rip a snake to shreds and will die off from old age, finally – win win. What could go wrong?

Admin
September 7, 2015 9:09 pm

Who would have thought – a versatile, intelligent top level predator can adapt to utilise whatever food sources are available.

Leonard Lane
Reply to  Eric Worrall
September 7, 2015 10:31 pm

Indeed. A top of food chain predator, omnivore, and scavenger smart enough and tough enough to live in the arctic climate apparently not near as fragile an these armchair experts have been bellowing about for years. Polar bears will do fine no matter how many global warming meetings, including Paris, armchair alarmists will hold around the world.

September 7, 2015 10:18 pm

2068!!!!????
Oh well, most of us will be long gone in 53 years.
Must be a very exact program to nail things down to a specific year 5 decades from now.
“In the year 2025 ….”
Aquarius.

Auto
Reply to  Wayne Delbeke
September 8, 2015 12:46 pm

Zager & Evans.
Yesssss!
Auto

CRS, DrPH
September 7, 2015 10:48 pm
September 7, 2015 10:52 pm

They talk of polar bears
As we watch their pigs fly by,
But it keeps us amused
That you cannot deny!
http://rhymeafterrhyme.net/ignore-the-flying-pigs/

Ancient Mariner
September 8, 2015 12:09 am

And warmer weather would, presumably, reduce their energy requirements anyway.

Martin Katchen
September 8, 2015 1:26 am

There’s more than one way to go extinct. Polar Bears adapted to life on the ice in the first place during the ice ages and split off from grizzly bears. They can still mate with grizzlies creating blonde “pizzlies” and gradually reintegrate back into the grizzly population from whence they came, becoming extinct through “miscegenation”. Something that ecologists are discovering happens in nature more often than they like to admit.

September 8, 2015 4:40 am

The Arctic sea ice is always going to be there as long as the Earth’s axis is tilted so that the Arctic gets little to no sunlight in the winter months as has occurred for the last 4.4 billion years running now.

old construction worker
September 8, 2015 4:54 am
September 8, 2015 5:14 am

But if there is no sea–ice, then surely the seals will give birth on land (like other seals). As it is the young seals that mostly feed the bears, then where is the loss of primary food?

Matt Bergin
Reply to  rockyspears
September 8, 2015 7:07 am

Rocky You are correct. These experts have no common sense. Seals are not fish and have to spend a lot of their time out of the water. With no ice the seals and the bears will both be on land. If the seals, with flippers, and the bears, with four feet, are both on land who do you think could run faster? In Churchill these omnivores have no issue eating our garbage. What part of that observed trait would lead a PHD equipped expert to conclude that Polar Bears only eat seals

emsnews
September 8, 2015 5:50 am

They want another Ice Age and we are at the tail end of a typical Interglacial so this wish for another Ice Age will be granted, most likely.

ralfellis
September 8, 2015 7:21 am

Ok, so when an intelligent and resourceful omnivore’s primary food-source runs low, they might eat something else instead.
Well who would have thunk it. Did they get a prize for this?
R

Auto
Reply to  ralfellis
September 8, 2015 12:50 pm

ralf
A prize?
A Nobel prize.
Apparently.
See, oh, I dunno, maybe a scientist – sensu lato, perhaps – with one or more names beginning with – as an example only, of course – M – Mike (the phonetic in the NATO phonetic alphabet).
Auto
Alpha Uniform Tango Oscar

Dreadnought
September 8, 2015 7:26 am

I wonder why they forgot to reassure their readers that, not only would poley bears survive if the ice were to recede, their population size has increased approximately five-fold during this supposed period of unprecedented warming and rapid ice-melt.
Perhaps they omitted that information on purpose in order to avoid straying from the doom-and-gloom narrative, in which case their paper might be just a fig leaf for another of their failed predictions.

TJA
September 8, 2015 9:18 am

Since they survived the Eemian, the phrase should be,”The did it before! They’ll do it again!”

Paul Westhaver
September 8, 2015 9:48 am

My Dad shot a polar bear in 1951 outside Resolute Bay.
The bear was trying to eat him and his Inuit companions.
The Inuits ended up eating the bear and sleeping in the bear skin.

Gary Pearse
September 8, 2015 9:48 am

With Churchill, Manitoba population of polar bears surviving after the Hudson’s Bay ice goes out a month or more before the arctic ice and forms a month or more later, ordinary folk have known the bear would survive any serious reduction in ice in the arctic. This is one of those such self evident truths that it is sickening to see ‘scientists’ proclaim the obvious. Another obvious thing that these ‘experts’ didn’t consider is that if the arctic warms, then the forest encroaches on the shores and brings no end of creatures right to their doorstep. They can eat seals that have come ashore as I’ve clarioned for several years, their prey now a linear hunting ground instead of three dimensional. They could even live in the woods most of the time and eventually re-mate with grizzlies. Heck, I’m only a geologist and engineer, but I seem to have come across enough data to make myself a polar bear expert as a hobby.

Gloria Swansong
September 8, 2015 9:56 am

That polar bears eat land resources has been known since the dawn of polar bear observation.
They have evolved specializations that help them prey upon ringed seals, other pinnipeds and marine mammals, but that doesn’t mean they can’t still eat the same things that their grizzly bear ancestors ate.

Dog
September 8, 2015 10:36 am

Bogus article,
Everyone knows that life is incapable of adapting to the constantly changing environments…
/s

Bruce Cobb
September 8, 2015 12:59 pm

Oh dear, it appears the Warmists will need a new standard bear(er).

September 8, 2015 1:37 pm

Few biologist understand climate change, but many assume the propaganda to be true. their observations are then subject to confirmation bias. Climate changes! Adapt or face extinction. Polar bears seem to get this better than these biologists. Since most of the current interglacial was warmer than now, polar bears should be able to survive well into the next glacial period. And we will probably learn to like polar bear steaks cooked over a nice grill in our igloos above the frozen city of Chicago.

patmcguinness
September 8, 2015 1:50 pm

Just so I understand: If man kills baby seals, that’s a horrible thing, but if polar bears DON’T kill baby seals, that’s a horrible thing too. Now, if the polar bears are not killing enough seals for the environment, can we let the baby seal clubbing recommence to balance things out?

September 8, 2015 2:14 pm

I would say humans are the most fortunate and we can influence our faith, but the animals have to adapt or they will have no other way. At least, we can try to do something…….

September 8, 2015 10:24 pm

If the polar bears get really hungry. then they can always snack on a few of the Global Warming Tourists visiting the area in search of signs of melting ice,

inquiring mind
September 9, 2015 10:00 am

Question
Year after year the summer temps in the Arctic do not vary significantly vs the average but the remainder of the year large variations that tend to be above the average. Any idea why?
Not a good case for global temp rise when the max temps are uniform.

September 9, 2015 12:27 pm

Polar bears are flourishing.
Why? We’re no longer shooting them.
QED.

Randy
September 13, 2015 10:00 am

my prediction-If the arctic melts we wont need to protect polar bears at all. The seals will have to use the land as a base, so they will be easier to catch then ever. They use the shores sometimes now anyway, so it is a safe prediction. Polar bear numbers will soar now that finding food is much easier, just follow the coast until you find them. So in the end we will end up reinstating heavier levels of hunting to keep polar bears in check.

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