Global warming warning: ecosystems in danger!

Arctic ecosystems are in particular dismay as the carbon footprint grows heavier and deeper!

Will there be a point in which we can turn back? For all readers who have seen The Lion King, do you remember the ‘Circle of Life’ concept? Well, our balance of life is shifting drastically since global warming has been on the rise in the past few decades, threatening many animals to extinction. If you think of an ecosystem as a web of resources, for which animals and plants are dependent upon each other and their environment for food, light, and living, if you add or take away something as crucial as food supply, it affects the entire rest of the web. That is what’s happening with climate change: it’s threatening all of us, and nothing that’s been done so far has been enough!

The arctic is one place where the ecosystem is particularly fragile. The flora and fauna have adapted to severe climate and seasonal weather changes, (such as with ice melt in the summertime, and polar bears move towards land, Grizzly territory, for example). But all of these species and habitats are in danger now, threatening some to extinction. If an animal’s extinction doesn’t bother you, think of the web of the Circle of Life – eventually, we as humans will feel the effects of that loss.

All plants and animals in the Arctic are starting to feel the heat, forcing unusual behaviors and extreme adaptation methods.

For example, red foxes have moved northward, into the territory of the Arctic fox, for which they both compete for the same food supply. Migrating caribou herds face problems with calving season, since the nutritious plants they feast on are sprouting earlier, and there numbers have since declined. According to Velasquez-Manoff, author of “Global warming takes a toll on Arctic ecosystems,”In the past 150 years, Earth’s average temperature has increased by about 0.4 C (0.72 F.).But the Arctic has warmed two to three time as much. As a result, spring arrives earlier and winter is less severe. Some plants begin flowering 20 days earlier than previously. Insects show up earlier. Herbivorous insects, like the winter moth, have moved north, defoliating birch forests in parts of Scandinavia” (Velasquez-Manoff, 2009).

The side-effects of global warming include (but are not limited to):

Reduction of species’ food supply

-Erratic seasons as plants and animals try to adapt to a changing climate: “season swap”

-Species extinction

-Possibility of bacteria and disease spreading, with the potential for mass extinction and/or improved bacteria and viruses

-Sea water rise, migration of certain animals and even humans!

-A rapid increase in some species’ populations

-Food and sanitation safety; global warming can greatly reduce the availability of crops and decreases the economic well being of agriculture and farming

-Extreme weather shifts, including an increase in tornadoes, tsunamis, hurricanes, and volcanic activity.

The problem with global warming is that it causes potential “sleeping giant” problems – issues that we can’t even full understand or appreciate until it’s too late – until they are right in front of us and there’s nothing we can do to stop them.

According to CNN international “Arctic species under threat’: “Shaye Wolf, lead author and climate science director of the CBD told CNN: “The plight of the polar bear due to global warming is very well known and familiar. But many other Arctic species are suffering a similar fate — from plankton all the way to the great whales.” (Knight, 2010)

And the Arctic region is now the most fragile place in all of the world when it comes to climate change. Pacific Walruses, like polar bears, are ice dependent; their numbers are declining. Regarding this, Wolfe says: “As we speak, there are 10 to 20,000 walruses holed up on Alaskan Arctic coastline. And that is attributable to sea ice loss.” Walruses are like polar bears in that they need rest, and they rest on ice; they cannot swim continuously.

Even underwater species play a role, and they too are being threatened by ocean acidification (please see previous blog for more info. on ocean acidification). According to the report by CNN International (2010):

“Shell-building marine creatures like the sea butterfly (Clione limacina) are particularly vulnerable to acidification.Their loss would be potentially devastating for other species.” (Knight 2010)

So what can we do about it? The answer is: REDUCE GREENHOUSE GAS EMISSIONS. “The Arctic is ground zero for climate change and we’re already pushing many species towards extinction. The key to preventing their loss is reducing our greenhouse gas emissions — specifically carbon dioxide — to a level of 350ppm or below. That is a level many leading scientists have called for to restore Arctic sea ice,” states Wolfe from the CNN report. (Knight, 2010)

For a further read, please view the following article:

Arctic change ‘to spark Domino Effect’

What kind of changes can we expect to see if global warming isn’t thwarted? What is already in a state of peril? Now we have come to the point where we must decide what is important to us, and how we are going to incorporate science and geo-engineering to help us re-balance the Earth. We need the help of our political leaders to guide us into sustainable manufacturing, producing and living; we need educators and scientists to speak out and we need our global community to understand the risks involved with our daily choices. We are responsible for tomorrow. You and I are responsible for Earth’s climate control, just as much as the person next to you. We are all in this together, and that’s the only way we will ever be able to make a dent in climate change!

References

Knight, Matthew (2010). “Arctic species under threat, report warns” CNN International. Accessed from: Arctic species under threat, report warns

Velasquez-Manoff, Moises. (2009) “Global warming takes a toll on Arctic ecosystem.” The Christian Science Monitor. Accessed from: Global warming takes a toll on Arctic ecosystems

Methane and “Black Carbon” also to blame for global warming

Ever imagine our world reaching the tipping point when it comes to global warming? The point of no return, the event horizon, if you will, of the catastrophic changes our Earth has been subjected to because of a mass release of CO2? We can look to our oceans, particularly those in the arctic region to find out just how fragile the balance is of CO2 absorption – and just how much we can handle before we face an eradication far beyond our sphere of knowledge or experiences.

We already know that CO2 is emitted into the atmosphere, and 1/4 of that is absorbed by plants and another quarter absorbed by the oceans. (Harvard Magazine, 2002). Now the temperature change in waters at all depths can have a significant impact on oceanic ecosystems, but it is true that warmer waters towards the surface of the ocean hold less CO2 than colder waters found in deeper water.

There are several factors concerning the rate at which CO2 is absorbed into the oceans. One factor “the availability of carbonate, which comes from huge deposits of calcite (shells) in the upper levels of the ocean. These shells must dissolve in ocean water in order to be available to aid in the uptake of CO2, but the rate at which they dissolve is controlled by the ocean’s acidity. The ocean’s acidity does rise with increased CO2, but the slow pace of ocean circulation prevents this process from developing useful momentum. It takes a long time for the increased acidity to reach the vulnerable calcite deposits, to dissolve them, and then to bring the carbonate cations to the surface where they can combine with CO2 in the surface waters of the ocean” (Harvard Magazine 2002) The problem is that the natural process that occurs in the ocean to balance out CO2 levels will not be quick enough to counteract the increasing build up of CO2 in the oceans, even though the process takes a long time.

James McCarthy, Agassiz professor of biological oceanography, featured in the article “The Ocean Carbon Cycle” by Harvard magazine, mentioned above, explains that deep waters eventually rise to surface in the normal pattern of oceanic circulation, the water “heats up and actually releases CO2.”

What kind of effects will this have on our oceans? How devastating can it actually be? There are already scientific studies describing the appearance of ancient bacteria being released from warming oceans, so what impact or changes might we expect to see? Some changes will occur over the next few thousand years, but others will show up even sooner. One problem is that once a carbon atom is absorbed into the ocean, it will remain present in concentrations for up to 500 years, according to an estimation given by Michael Elroy, Butler professor for Environmental Science (Harvard 2002). That’s a long time, and if we think of this in conjunction with other factors, it’s not hard to see why we are seeing physical changes in our ocean already, such as the case of ocean acidification.

Oceanic species are already suffering from the carbon build up we have seen in our oceans. Corals and sea plants have been recorded to migrate to find cooler temperatures, but they can only survive in very specific climates, so once the boundary of their adaptation is reached, when they migrate no further, they are in danger of going extinct, much like many species from the animalia class that are already dying off at alarming rates.

Rob Dunbar sheds further light on the dangers of ocean acidification below:

During the summer seasons in the Arctic region, ice melt has been significantly greater than in past seasons due to global warming, and this has been causing increasingly dramatic changes in Arctic ecosystems, which are being affected far quicker and much more prominently than other places. Surfacing reports have stated that the entire arctic region and all ecosystems within are suffering from such a dramatic shift in warmer climates. According to the Arctic Monitoring and Assessment Program, enacted by scientists from Norway, United States, Canada and Russia state that black carbon, or soot referring to ozone and methane – are now contributing to a rapid increase in ice sheet melting, not just CO2. The most prominent example of this is the thinning of sea ice. According to the article  Climate change hitting entire Arctic ecosystems, posted by the Guardian from writer John Vidal in Norway: “The most striking change in the Arctic in recent years has been the reduction in summer sea ice in 2007. This was 23% less than the previous record low of 5.6m sq kilometres in 2005, and 39% below the 1979-2000 average” (Vidal, 2009). In Russia, tree lines are advancing up the hills and sea levels are rising due to rapid ice melt. In Greenland 2007, ice melt was up to 60 % greater than its melting speed in 1998 (Vidal, 2009).  Since the ice has been melting far more rapidly, the warmer waters of the Pacific and the Atlantic influx have been causing a mingling of warmer waters, too. According to Vidal, “In 2007, some ice-free areas were as much as 5C warmer than the long-term average,” and the problem posed by methane black carbon is the loss of reflective services the ice gives as protection to its surrounding ecosystem. “The loss of reflective, white sea ice also means that more solar radiation is absorbed by the dark water, heating surface layers further.” (Vidal 2009).

As for those of us who are still stuck in the mindset that the earth’s rotation and own seasonal shifts are to blame, not humans, for the increase in CO2 found in our atmosphere, then consider this:

According to recent studies, if we are to consider the effects of orbital shift on ice melt, the Arctic region should at present, be cooling now warming! The article  by Velasquez-Manoff “Earth is now 0.6 million miles farther from the sun during the northern hemisphere’s summer solstice than 2,000 years ago, and receives less of its energy.” And until as recetnyl as 50 years ago, the Arctic was gradually cooling. Does this mean that humans are fact responsible for throwing off the balance of orbital shifts? To think that we as a race could have such a dramatic impact on the world for which we live and thrive – we may have to start thinking about what’s necessary to us, and what’s important for future generations. Because right now, with no further changes to create more sustainable energy, our hope to live much longer without dramatic and inconvenient impacts from global warming, may just be thwarted by Mother Nature herself.

References:

“The Ocean Carbon Cycle” (2002) Harvard Magazine. Accessed from: The Ocean Carbon Cycle

Velasquez-Manoff, Moises. (29 Oct 2009). “Global warming takes a toll on Arctic ecosystem.” The Christian Science Monitor. Accessed from: Global warming takes a toll on Arctic ecosystems

Vidal, John. (28 April 2009). “Climate change hitting entire Arctic” The Guardian. Accessed from: Climate change hitting entire Arctic ecosystems

A captive polar bear breeding plan?

New efforts have been underway to ensure that the species doesn’t meet an early demise due to global warming: captive breeding. The breeding plan was devised by Highland Wildlife Park, where Walker, a cub who hadn’t reached sexual maturity at the time was relocated to Scotland to be raised in a new breeding programme.

This decision was met with reservations from Ross Mignette, campiagns director at OneKind, an Advocates for Animals Charity organisation, stating that the needs and behavioral patterns of polar bears in the wild is far too complex to mimic in captivity.

But could this project become a successful resolve to the issue of vanishing habitat polar bears face?

Mignette says: “Any captive breeding programme is inherently flawed as any bears born are likely to be incapable of surviving in the wild, and therefore condemned to remain in captivity for the rest of their lives.”

His fear is that polar bears will be bred in captivity and then unable to be returned to their natural habitat, (a major issue I discussed with zoos in a previous blog), so it is probable then that we would be breeding polar bears that were potentially never going to be released back into the wild, so we will have many more bears, but they will all be stuck in zoos. Is this then going about correcting our problems in all the wrong ways? Mignette doesn’t seem to be too keen on the idea of keeping polar bears captive at all.

“True conservation,” he says, “is about protecting these wonderful animals in their natural habitat.” But will that be feasible?

Even if a mass number of the public were to cut back on burning fossil fuels and jump on the sustainable bandwagon all at once, we would not see an immediate decline in CO2 concentration levels in the atmosphere and oceans; because of the damage done, it would take time before any real reduction could be seen.

BUT this doesn’t mean that we are doomed: eventually we would see results, and therefore it is EVEN MORE pressing that we get people involved and interested in sustainable practices, because even after these changes are made, it will take time to see the progress the changes will make.

Polar bears don’t have a long time left with global warming increasing on the planet; fast action will be needed.

On a lighter note, a breeding program at Rhenen Zoo in the Netherlands has been seeing some of its own miracles: two new baby bears have been born and are thriving well in captivity. The Manager of the Ouwehands Zoo, one of two zoos partiicpating in a breeding program, says it’s due to Huggies (the mother bear’s) relaxing style of mothering.

http://english.ntdtv.com/jwplayer/player.swf

Even though captive breeding is no laughing matter, it does help to take things with a sense of humor for educational purposes. After running across this video, I have decided to share it:

References

BBC News:(3 Nov 2010) “New Polar Bear in Highland Wildlife Park Breeding Program.” New polar bear in Highland Wildlife Park breeding program

Are Zoos Helping or Hindering?

The topic of showing animals to tourists from behind protected walls and from behind enclosure doors, bars, or windows has always been a controversial and heated debate. Is the illusion of freedom convincing to the animal? Do zoos really do a good enough job of replicating the environment the animals come from? These are the kind of questions that I wonder about when I look at animals from behind the protection of those big enclosure walls…The ethical dilemma of zoos is  something people will see differently and disagree on quite frequently. I want to look at some of the benefits of zoos, while looking for the potential cons of these benefits as I brainstorm.

Science and/or studying animal behavior may give us clues to patterns in the animals’ lifestyles, and it may also shed some light on whether or not they are happy, but we will never know if they comprehend their entrapment and how they relate or view their confinement much more than the through a window of science and testing.

Image

Willy the polar bear at the North Carolina Zoological Park in Asheboro, NC. This picture was taken in 2006. Accessed from wikimedia commons at: http://commons.wikimedia.org/wiki/File:Polar_bear_Environmental_enrichment.jpg

So, here goes. I am going to list some potential benefits of zoos as well as their cons below:

1. Zoos can be educational and fun. Zoos are great in that parents and children, and generally all types of people can get enjoyment out of seeing (and in some cases touching) the animals. We got to face it, there’s many of us who will never see some of these animals if it weren’t for the fact that zoos exist. In my opinion, that’s not a good enough reason for zoos to be considered a ‘good resource’ for animals. There are, however, much more poignant reasons for their potential benefits and I am about to list them.

2. Zoos bring tourists and tourists bring money – zoos can help set up funds or promote the conservation of a threatened species by encouraging visitors to donate to help that animal. According to an article posted on NPR (the national public radio website), writer Elizabeth Shogren reports the Pittsburgh Zoo is doing an exceptional job at promoting awareness for polar bears in particular: “Some people see polar bears as fluffy friends, others as fierce predators. But there’s no disputing that the bears are extremely popular, and when visitors stop by, the zoo has handouts at the ready. They explain how reducing energy use and recycling can cut the greenhouse gas pollution that contributes to global warming and benefit polar bears.” (Shogren, 2008).

3. Zoos promote awareness of endangered species. One particular man, Jim Gessler and a visitor to the Pittsbrugh zoo, has made drastic changes to his lifestyle, encouraging his daughter to do the same. “I’m turning off lights when I leave the room, I don’t have a car anymore.” And his daughter Ann Gessler has “given up meat” because the amount of energy it takes to make a hamburger is more than necessary (Shogren, 2008). In this way, zoos can inspire us to see clearly, and to make physical changes to our lifestyle. If enough people took direction like Jim and his daughter, then a dent might be made in the environment at last!

4. Zoos drive people to act on behalf of their experience, and perhaps to donate or visit regularly, or to look into the animals further on their own time; basically, it allows people to engage with the animals, which helps deepen the connections people make to more primitive aspects of the animal kingdom. Since we don’t get to see these animals everyday, it is a real treat to be able to interact with them – and sharing a moment with an animal can do wonders for a person’s perception of how that animal thinks, acts, feels, and more. Some may argue that caging these animals and allowing people to see them makes people take them for granted, but I think generally it works the other way around: that zoos act as a facilitator to greater understanding of what’s out there, and how these animals really work. Because people don’t know, and that’s the underlying dilemma. Zoos, therefore, act as a form of science communication to the general public – as well as an experience they likely wouldn’t get any other way. Typically that rarity drives people to appreciation, not undervaluing.

5. Zoos can provide breeding grounds for animals that are close to extinction or having trouble mating in the wild. This one is a little more controversial than the others, but it’s true; zoos, and some parks and sanctuaries as well, have the means to aid animals in the act of procreating. Is this man’s place, we need to make sure our objectives aren’t skewed when we do this. And many people will disagree with me on this, but I believe that if done correctly, man-made breeding grounds, or captive grounds, can work. The controversy is that if done wrong, then when the animal is released into the wild, it will not have gained skills sufficient to behave in the world, and will therefore either die of starvation, be hunted by predators, or die from climate causes. According to the Smithsonian Conservation Biology Institute on captive breeding, there are particular motives and goals of captive breeding programs, and they are as follows:

“The goal of most captive breeding programs for endangered species is to establish captive populations that are large enough to be demographically stable and genetically healthy. This means:

  • maintaining a healthy age structure
  • ensuring that reproduction is reliably successful
  • protecting the population against diseases
  • preserving the gene pool to avoid the problems of inbreeding” (Smithsonian National Zoological Park)
But all of these point to the question of whether it is still ethical to place animals in enclosures and inhibit them from their natural habitats. It is a topic that will always be debated between animal conservation groups, groups like PETA (People for the Ethical Treatment of Animals), zoologists, zookeepers, and many more! It’s interesting because many people have really strong opinions about zoos – whether they are good or bad, etc – but I wonder the ratio of people holding strong opinions to those that acknowledge and recognize the complexities of them.
What about animals that are orphaned in the wild? Zoos can be excellent resources for orphaned or injured animals. Take a look at this video of Qannik, an orphaned cub found in the North Slope of Alaska taken in and cared for, and then tell me that zoos can’t do some good!
Personally, I don’t believe in inprisoning an animal unless it is sick and needs to be nurtured back to health. There are also cases of animals that will never be able to return to the wild; these are the types of situations in which I think zoos are okay – but even then is it a stretch. A zoo goes against a natural occurrence in nature – they are manmade, and in some regards but with far less of a danger element – it brings about the same elements as the blockbuster film Jurassic Park. Like anything, it’s all a matter of perspective and culture. But I don’t believe that wild animals should be kept captive unless they need to be due to health reasons. That is my personal opinion on zoos.

Reference List:

“Endangered Species Science: Captive breeding.” (2012). Smithsonian Conservation Biology Institute. Accessed from: Captive Breeding Populations

Shogren, E. (2008). “Polar Bear Population Struggles as Sea Ice Melts.” NPR. Accessed from Polar Bear Population Struggles as Sea Ice Melts: A look into how zoos are helping polar bears

Climate Change Fueling Action?

I want to spend some time with the public perception of climate change and look into the process of perception shift when it comes to the mass media. First and foremost, there are still a hefty number of people throughout the world who don’t believe that climate change exists, that the warming of the planet represents a natural trend that should merit no extreme action from us.

To this I ask of these people, (after I silence the screams of agony in my head), were YOU around several million years ago to witness the ebb and flow of the Earth’s natural climate trends? NO. You most certainly were not, so how can you boast that we are not at least a precursor to this very elaborate and complex issue? If there is even a minimalistic chance that we are contributing to warmer sea temperatures, more extreme weather and volatile storms, excess CO2 being emitted into the atmosphere and soaked up into the oceans, then shouldn’t we, even if we are small contributors (which more science has been surfacing that we are NOT minimally responsible, we are very much responsible for these changes), well shouldn’t we at least be accountable and proactive about the effects that our daily human lives have cost the planet in past years? And to think, even science has pointed that in past years we have made a much larger impact on the world than we could ever have imagined many years ago, especially with the technological shift period. BUT FINALLY, I am happy to see and hear that more people I talk to, I hear about, and listen to, are believing that man is not only a part of the problem of climate change, but also the solution, to at least attempt to counteract some of the damage that’s been done in efforts to help turn things around a bit here.

This brings me to the work of environmentalist Bill McKibben, whose recent article “Connecting the dots of this climate change crisis,” has proved that more and more people around the globe are jumping on the climate change bandwagon and stepping out to protest against it.

Connecting the Dots of this Climate Change Problem

“After a year with a record number of multibillion dollar weather disasters, seven in ten Americans now believe that “global warming is affecting the weather.”

This is all good news, but protesting in itself can only do so much – (besides get you thrown in jail, as many steadfast activists know); what we need to do is find a way to fuel the protests into brainstorming engaging and inventive strategies to help lessen the polarization of climate change and unify the world in the fight against global warming.

Bill’s recent article is an excellent source of showing how such a unity can take place on a global scale. If you click on the link that I have put in the center of the page, you can read on about just how much a single day devoted to recognizing climate change impacts and preserving the Earth can do for our global community.

With the help of Steven C. Arnstrup, a hero of mine who has been studying polar bear movements and physiology for over 24 years in work with the United States Geological Survey at the Alaska Science Center, the aim of today’s blog will be to discuss polar bear evolution and how these beasts came about. The man, also, has a record for being bitten by polar bears as well as penguins; both the northern and southern hemispheres have taken a chomp! He has also studied black bears.

I have spent quite a bit of time discussing the basics of bears, but haven’t yet addressed one of the most pressing matters pertaining to all species development: the evolutionary process of one of the world’s fiercest land animal (and marine) animals.

Polar bears share a common ancestor with the brown bear, making an evolutionary divide during the late Pleistocene. Polar bears dating back to this period were even larger, described as “gigantic” and have seen changed in size and appearance. Perhaps now they are the smallest they have been in their history.

There seems to be a special connection between Archipelago Brown bears and polar bears, distinguished from mitochondrial DNA (mtDNA). The question of genetic diversity within groupings of bear types dependent on location may give rise to special connections regarding bear evolution; or it may instigate further questions for scientists but Armstrup as worked to make a connection. The Kodiak Brown Bear is the species of bear that can be found on the Kodiak Archipelago in south-western Alaska. The Kodiak Brown Bear, or commonly known Grizzly Bear, is not listed as endangered, unlike the Polar Bear, as the brown bears are land mammals are not directly affected by the shrinking ice habitat.

According to a research essay devised by Armstrup, genetic and fossil evaluation has played an important role in deciphering distinctions between these two bear species.

Armstrup explains that in a study conducted by Talbot and Shields (1996b) found mtDNA sequence divergence rates that aligned with the ones that were classified by previous studies by Cronin et al. (1991); these suggested that Archipelago brown bears separated from other subspecies of bears some 550,000 to 700,000 years ago, and the mtDNA taken from polar bears also suggested the rise of the new genre of bear – the polar bear, Ursus Maritimus tyrannus – was divided after that some 200,00 to 250,000 years ago in the Pleistocene, which aligns with fossil records taken fossil records of both bear types. (Arumstrup 2003, p 591). A more recent article in LiveScience (2010) claims that polar bears probably first emerged as real “polar bears” from the evolutionary rope some 150,000 years ago, according to a polar bear jawbone’s genetic material. The jawbone, which is between 110,000 and 130,000 years old, may tell researchers even more about polar bear evolution. According to the article composed by Clara Moskowitze (2010), “he researchers drilled into a tooth on the bone to extract mitochondrial DNA, which is DNA from the energy-producing part of the cell called mitochondria. The scientists then sequenced this DNA and compared it with the DNA of modern polar bears, and modern brown bears from Alaska’s Admiralty, Baranof and Chichagof Islands, which are the polar bear’s closest relatives. LiveScience was able to talk with Charlotte Lindquist of the University of Buffalo, team leader of this particular event, and found that the polar bear genome used for mitochondrial testing is the oldest mitochondrial genome ever to be tested. (Moskowitz, 2010)

The skeleton contained the lower left portion of the jaw, with a single tooth still intact!

So what could this mean for polar bears? Scientists now know that polar bears originated and broke off from brown bears at least 110,000 years ago. The Understanding Evolution (2010) website explains “Having already investigated the fossil’s anatomy, stratigraphy, and mitochondrial DNA (as well as the molecular clock in that DNA), the team of researchers studied one more line of evidence unearthed with the fossil: the atoms that compose the tooth embedded in the jawbone. An organisms’ diet strongly influences the sort of atoms that are deposited in its body — specifically the ratios of atoms with different numbers of neutrons. By studying the carbon and nitrogen in the bear’s tooth, the researchers discovered ratios that were exactly what we’d expect to observe of a bear that gets its nutrition from seafood! Just 20,000 years or so after they diverged from forest-dwelling brown bears, polar bears had already evolved their distinctive marine lifestyle. For a large mammal, that’s evolution at breakneck speed”

The polar bear, then, was a quick adaptor, a real testament to the science of evolution. It is likely that during the break off, many of the Kodiak bears died from an inability to adapt, but a few must have survived and formed adaptive mechanisms henceforth. But why did polar bears evolve different physiological structures from their relatives the Kodiak Brown Bears? What is so different about them?

When polar bears first began their new evolutionary line, they likely had the same teeth and body type, but over the next few thousand years, their skulls elongated and body shape changed. It is thought to be only recently, in the last 10,000 years, that they have developed “polar bear teeth.”

According to LiveScience, “polar bears are a very specialized species. Whereas brown bears are more generalized and can survive in a variety of habitats, polar bears evolved to take advantage of a very specific ecological niche.” (Moskowitz, 2010). Which explains why their melting habitat endangers the polar bear but not necessarily the Grizzly.

 

                                                     [Please find further information at: http://www.polarbearsinternational.org/sites/default/files/pdf/PolarBearsComprehensive.pdf]

and also,

http://www.livescience.com/10956-polar-bears-evolved-150-000-years.html

and of course,

http://evolution.berkeley.edu/evolibrary/news/100401_polarbears

mDNA and Fossil Exam Links Bear Evolution

10 Reasons why Polar Bears are Exceptional Beasts

Hello again polar bear enthusiasts!

After some time spent researching further into polar bears and pursuing the different aspects of their physioogy, environment, adaptation methods *teaser!* (which I will talk about next), and behavior, I have found that these dangerous giants are in fact, very worthy of studying and most certainly, saving from their endangered status. And I would like to dedicate this blog to some very surprising and interesting facts about polar bears that aspire to show why they are one of natures most amazing creations!

Starting with the top…

10. The skin beneath their beautiful translucent fur is black, which may help them to retain heat from the sun and keep their body temperature up. The average body temperature of a polar bear is 98.6 degrees Fahrenheit, or 37 degrees celsius, which is the same as the human body! On average, pushing aside the physiological changes that have been noted in some females, the polar bear has a greater chance of overheating than it does from freezing in the frigid temperatures.

9. Wide, partially webbed feet help the polar bear wander across long stretches of ice, as well as to push through water and swim for a long time. In fact, they are able to swim so much, they have been partially classified as marine species as well as land dwellers! Their feet are furred and shielded with Papillae, or dermal bumps, to help them from slipping on the icy surfaces; (Polar Bears International) Basically, they help keep traction, like soccor cleats on a field. Plus, their sheer size makes them incomparable to many paws in the animal kingdom. Just look below!

Image

^^ http://commons.wikimedia.org/wiki/File%3AEisbaer_hintertatze-3.jpg ^^

8. Polar bear claws are not only deadly, they are powerful tools to help snatch and drag prey. Like most carnivores, their claws are able to help their teeth shred and eat meat. Their claws can dig into flesh and drag prey from watery depths, onto land where they can feed, tugging between 40 and 90 kg (150 – 200 pounds) of pure muscle and flesh. (Polar Bears International)

7. Polar bears, unlike other bears, are able to hibernate and walk at the same time! Instead of experiencing extended periods of rest within the warmth of den. Though polar bears do create what are called maternity dens to give birth, they do not need to hibernate in the strict sense of the word. Instead, polar bears experience a slowed metabolism and continue to carry out basic functions as they move, eat and sleep. (Polar Bears International)

6. Polar bears are amazing hunters, at the top of the food chain! The only true threats to these amazing and dangerous animals is man and environmental factors, such as global warming and a shrinking habitat, which poses threats to the bears by changing the overall ecosystem of the polar bear habitat. Bears were previously (and are still in some countries) lusted after for their fur, so poaching by man has been the second main threat that polar bears are challenged with. Because they are now listed as ‘threatened’ species, hunting them in the United States is now taboo. Polar bears also help to keep ringed seal and other seal species down by hunting them and decreasing the chances of overpopulation.

5. Blubber is not just for whales! Polar bears exhibit a layer of blubber, a stocky layer of fatty tissue beneath the skin surface, which helps them to retain warmth and keep energy levels up. When feeding, the polar bear feeds specifically on the blubber of its killer, the highest caloric value, and most of the time leaves the rest of the meat for scavengers, such as the arctic fox and younger or other bears. (Polar Bears International) The blubber and meat from its meals helps the polar bear to build up its own blubber reserve and sustain its massive appetite and sheer size and muscle. Their blubbery layer can make over 4 inches of insulation!

4. Boasts the biggest land carnivore! And arguably one of the most vicious, too. The largest polar bear was over 2,000 pounds, while a typical male weighs between 775 -1200 pounds (351-544 kg). (Polar Bears International) Female bears are smaller than males, and usually weigh in around 150 to 295 kg. Nevertheless, these bears are massive! Not only one of the largest land roaming beasts, but the largest of the bear subgroups. No one with half a brain would mess with a polar bear!

Below is a picture displaying a size comparison of the polar bear (represented in blue, and not a dinosaur) next to man. For additional comparisons, dinosaurs from the Triassic, Jurassic and Cretacious periods have also been included. I find it interesting that the polar bear is technically represented as being in a similar league as carnivorous ancestors of the past:

Image

^^ http://commons.wikimedia.org/wiki/File%3AGiantpredatorsscale1.png ^^

3. Polar bears are capable swimmers! Polar bears have been known to swim from land to ice floes and sometimes vice versa in search of food, particularly ringed seals. But just how far can polar bears swim? Well, to start off, the distance between land and ice floes was significantly smaller before global warming temperatures rose and melted the ice, making the distance between land and ice sheets to become longer. According to an article in Earth News, one polar bear made a revolutionary swim of nine days in length, swimming for 697 km before exiting water. This feat baffled scientists; research zoologist George M. Durner has said of the feat: “This bear swam continuously for 232 hours and 687 km and through waters that were 2-6 degrees C,” and furthermore, “We are in awe that an animal that spends most of its time on the surface of sea ice could swim constantly for so long in water so cold. It is truly an amazing feat.”(Davis, 2011, Earth News BBC). Polar bears can regularly swim over 48 kilometres, (30 miles) in search of ice and food. They are built for this action due to seasonal changes, when ice melts during the warmer seasons. In some cases, cubs are even able to survive these swims though it varies on the strength of the cub and the feeding season. (Hance, 2012) There is, however, no doubt that global warming has put a strain on these cubs’ abilities to keep up with their mothers during much longer swims since ice has begun melting faster due to global warming.

2. Double – blanketed beasts! Polar bears have two layers of fur – the outermost layer, a thick translucent and hollow blanket that sits atop a second layer of thick fur in order to keep the bears insulated and warm. Beneath their fur, is a blubbery and thick layer of fat under their skin that maintains insulation as well. If overheating, as mentioned before, is at times an issue for our polar bears, how will they adapt to warmer climates and more severe water temperatures?

And now for number one!

1. They are some smart puppies! Eerrr…bears. They have been documented to express more human emotions than most people realize, and some scientists have documented them throwing fits or tantrums, for which they have been known to toss ice. In some instances, this may be a territorial or scientifically -reasoned phenomena, but on top of that they are smart enough to know when and where the ice is too thin to simply lumber across. In these cases, they slide down on their stomachs or crawl in order to make sure they do not fall through the ice (even though we have established they are adept swimmers).

Now, these are just some of the reasons why polar bears are such fascinating creatures. There is so much more that we do not know about them – but that I, and I am sure many others – want to find out! Stay tuned for more polar bear updates and learn more about these wonderful beasts as well as what we as compassionate and concerned citizens can do to make sure these beauties stay around!

References:

Davis, Ella (2011) “Polar bear’s nine day swim in search of ice. Earth News. > http://news.bbc.co.uk/earth/hi/earth_news/newsid_9369000/9369317.stm

Hance, Jeremy (2012) “Just how far can a polar bear swim? MongayBay >http://news.mongabay.com/2012/0503-hance_polarbear_swim.html

“Polar Bears International” > http://www.polarbearsinternational.org/polar-bears/faq