WildFact
›
Information Section
›
Terrestrial Wild Animals
›
Carnivorous and Omnivores Animals, Excluding Felids
›
Bears
Polar Bears - Data, Pictures and Videos
Polar Bears - Data, Pictures and Videos
|
Polar Bears - Data, Pictures and Videos
|
Polar Bears are the largest land carnivores. They live extremely hard life and looks very cute and lovely. They are very strong predators and are able to hunt very large prey like beluga whales and walrus but their primary food source is fatty seals.
Despite of land carnivores they are marine animal and spend their time mostly in Arctic sea ecosystem. They are also excellent swimmers. This thread is dedicated to these magnificent creatures, please share your data, picture and videos.
A study of polar bears behavior
It’s close to that time of year again when the polar bears of Hudson Bay move ashore for the summer, which means it’s also time to look back on a very interesting year of tracking our collared bears. This year, each polar bear that we followed chose to do something very different, teaching us a lot about the variety of individuals that we track. A few polar bears stayed close to Manitoba all year while others chose to travel almost right across Hudson Bay, getting close to Quebec and Ontario. One polar bear even traveled far north to Nunavut with her cubs and back. That’s a long round trip! Each polar bear is different, just like each human is different, so we expect there will be a variety of choices made within a population. Where a bear chooses to travel can depend on age, if the bear is male or female, or if it is a mother with cubs (and, if so, what is the age of those cubs). Some choices may even depend on what the polar bear was taught by its mother when it was a cub. We don’t always know why polar bears choose to do what they do. This is an area of polar bear science that we are trying to learn more about. We do know that the choice of where to travel in Hudson Bay is related to the time of year. There are a couple of critical times during a polar bear’s year where we may see some common choices made even among very different bears. One example is during the season when seals are giving birth, or pupping season. Seals in Hudson Bay have their pups in the spring. One of the main pupping regions is near the west coast of Hudson Bay, north of Manitoba. This year, many polar bears returned to this region during the spring for better hunting opportunities, even those bears that went far out into the middle of the bay in early winter. When seal pups are young and naive, they are easy meals for a hungry bear and pack a punch of fatty goodness. In areas where there are many seals pupping, a polar bear can expend little energy but get a lot of food—it’s equivalent to fast food for humans. This yummy situation draws polar bears in from all over Hudson Bay. It’s the main time of year when polar bears build up the body fat that will last them through their summer on land. Another critical time of year for polar bears is during the sea ice break-up. We don’t know when the ice break-up will happen in Hudson Bay this year, but we can see that it’s starting now, based on satellite images. We hope the ice stays into July, because if it breaks up a week or two earlier than normal, hunting time is reduced and so is bear body fat. By now most of our bears have made their way back to the west coast, perhaps preparing to get back on land as soon as the ice concentration gets too low. However, our tracking shows that there is still one bear pretty far north and another off the coast of Ontario. Will these bears return to land in Manitoba before the ice break-up? Will they stay the summer in Ontario or Nunavut (which has happened before)? Or will they just get off the ice in these provinces then walk back to Manitoba? It is a pretty neat thing to be able to track polar bears and their choices, but it will be a long time before we will understand why they make these choices. One reason we are interested in how polar bears make choices is that we are seeing some shifting conditions in Hudson Bay over the long term, and we don’t know how polar bears will respond. Will they stick to past preferences or become flexible as conditions change? Will they follow what their mom taught them or realize they have to do things differently? The answers to these questions could help us prepare for conserving polar bears in the future. So while many of us look forward to the warm summer months with happy anticipation, polar bears are about to have their favorite time of year draw to a close. Hopefully, they had enough to eat this winter and have enough body fat to live off of this summer. So far we think our collared bears are doing well and hope to spot them and their cubs again this fall. We wish them a cool and short summer and cross our fingers that the ice comes back soon!  *This image is copyright of its original author movements of satellite-colllared polar bears on Hudson Bay. You can see real time information of each bear from Hudson Bay and Full Map. I suggest you to check the following link (Bear tracke Map) http://www.polarbearsinternational.org/a...ar-tracker This original Article is from http://www.polarbearsinternational.org Contributor Alysa McCall   *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author 
Two adult polar bears captured and weighed in Alaska in August 2008. The female is 26 stones (165.1kg) while the huge male is 110 stones (698.5kg).
http://www.dailymail.co.uk/news/article-...fully.html 
Fascinating records Richards, great job. Until now, I believed that the heaviest polar bear actually weighed by scientists was a male of 654 kg. There are other specimens that could not be weighed on land or by helicopter and that where estimated at over 800 kg, but they are just that, estimations.
The new figure of c.699 kg is great, and most be quoted in the future.
Polar Bears from Space: Assessing Satellite Imagery as a Tool to Track Arctic Wildlife
Scientists have used satellite pictures to monitor the creatures off the coast of Canada, and claim the technology could be used to keep tabs on how the rapidly melting Arctic ice is affecting their numbers. The images are said to be so detailed, each shot uses around 2.5GB of computer space - 1,300 times more than the average iPhone photo.  *This image is copyright of its original author Figure 1:While Analyzing, presence of clouds could make detecting the polar bears more harder. The locations of the polar bears are circled on each image  *This image is copyright of its original author Figure 2 : Polar bears detected with high resolution satellite imagery and during the helicopter-based aerial survey. Target imagery was acquired from Rowley Island (dark shade) in northern Foxe Basin, Nunavut with the WorldView-2 and Quickbird satellites on September 3, 2012.Transects were spaced at 7 km intervals during the aerial survey. The Foxe Basin polar bear subpopulation is outlined in black and the study area is shaded red in the inset.  *This image is copyright of its original author Figure 3: Example of high resolution satellite imagery used to detect polar bears. Imagery was procured from Rowley Island in Foxe Basin, Nunavut during late summer, 2012. The target imagery (a) was searched for polar bears, and the reference imagery (b) was used for comparison. Polar bears are present in the example target image but absent in the reference image (yellow circles). Landscape features that remain consistent between images, including rocks and substrate, are denoted with red arrows. For more detail visit http://www.plos.org/wp-content/uploads/2...pleton.pdf
Here are some picture of polar bear from their habitat
 *This image is copyright of its original author Polar bear picture - swimming in his habitat. Sad to see the ice is melting.  *This image is copyright of its original author Polar bear image - swimming in sea  *This image is copyright of its original author Polar bear photo - in his habitat, unfortunately habitats of polar bear are shrinking
Polar bears in Wood (1978):
Here is the part about the polar bear in the Guinness book, enjoy the reading.  *This image is copyright of its original author  *This image is copyright of its original author 
what do you think they're doing?
 *This image is copyright of its original author *This image is copyright of its original author after a heavy lunch  *This image is copyright of its original author [img]images/smilies/biggrin.gif[/img]
Norwegian and Russian scientists are going to cooperate on counting the number of polar bears around Svalbard and Franz Josef Land.
For the first time in 11 years the number of individuals in the Norwegian-Russian stock of polar bears will be counted. In 2004 scientists counted some 3000 bears in the area. http://barentsobserver.com/en/nature/201...tory-25-02 
Hi everyone
Do we know the longest HBL recorded for polar bears and alaskan brown bears? I've seen figures of 241 cm for a Yellowtone Grizzly and 264 cm for a North Eastern Siberia brown bear
Hi again @tripoliraider.
From several sources (I will post the data later), I have found maximum figures of 250 cm and 285 cm for polar bears. I will need to search data on the Alaskan brown bears, but for the famous Ussuri (Rusian Far East) brown bears, Kucherenko (2003) provide a maximum figure of 252 cm in head-body.
thank you GuateGojira
Peter posted a very interesting table here http://wildfact.com/forum/topic-on-the-e...is?page=21 Some of those measurements (278 cm in body length) are extremely impressive for "north eastern siberia brown bear". I wonder if they represent straight line body lengths...
Polar bear taste for land food is growing this cause worries among scientists
Studies from 2 different sources suggest that polar bears are increasingly coming ashore in search of food. The prospect of having to search for food on land would seem to be a recipe for disaster. But while that is increasingly the case for the species in parts of Norway and Canada, as a pair of recent papers suggests, the reason, and the impact, is less clear. It has long been known that during summer months, polar bears will supplement their diet, primarily seal caught on sea ice, with food they can find on land, including berries, mushrooms, eggs and carrion. The two papers, released earlier this month, express concern that foraging appears to be making up a larger portion of the polar-bear diet, and that this may signal of an ecosystem that is out of balance. In the first paper, published in Frontiers in Ecology and Evolution, scientists noted that over the course of the last decade, an increasing number of polar bears in the Norwegian Arctic were foraging for eggs in bird colonies. Over the course of the study, the bears also appeared to be arriving earlier each year, and were now showing up as many as 30 days prior to the original observations. While this was not a direct sign that bears are in trouble, the study’s authors worry nevertheless that the trend correlates with the gradual retreat of the sea-ice margin. Another concern was the number of eggs polar bears must consume in order to survive (as many as 20kg a day for an adult) and whether nesting colonies could survive the onslaught. The scientists, who were initially studying bird populations in the region but gave up in order to focus on the increasing amount of polar-bear foraging, report that in some years eggs are taken from as many as 90% of nests. The authors suspect the increased foraging is linked to a receding annual ice extent, but suggest there may be other explanations, including an end to hunting in 1973 and what appears to be a population rebound. A combination of all three factors – more bears, an end to hunting and worse maritime hunting conditions – is likely to be involved, but the paper notes that a similar increase in terrestrial activity had been noted in Greenland, even though polar bears continue to be hunted there. The second paper, this one published in Frontiers in Ecology and the Environment, seems to support the evidence that polar bears are increasingly coming ashore to eat. Instead of looking at frequency, however, this report investigates whether polar bears could successfully transition to a land-based diet. Its conclusion is that this is unlikely. Given that other species of bear, such as the brown and the grizzly, do survive on many of the types of foods polar bears have been observed eating on land, it had been suggested that a transition might be possible. The scientists, however, point out that these species are smaller and have an easier time converting plants into energy. For polar bears, which derive the energy they need from the blubber of seal and walrus, it would be all but impossible to consume enough plant-based food to keep them alive. Another important difference is that polar bears do not hibernate, which would preculde the adoption of a terrestrial diet in winter. Although neither of the papers differ significantly from previous findings or the historical observations, they did present a number of differences, including the location where foraging was happening and its increasing frequency. Though still relatively rare (in both reports, the number of bears recorded coming ashore to eat was marginal, perhaps only 30 in each area, out of populations that may be as large as 3,000), the data suggest the trend is increasing. But the rise may reflect polar bear’s opportunistic eating habits just as easily it does a lack of seal. "They will eat anything they can get their teeth on, trash even," says Andrew Derocher, a biologist with the University of Alberta. "They prefer to make their living eating seals, but when that’s not there they’ll look for something else." He suggests that if there were nothing to forage on, the bears would likely search for seals elsewhere. This, according Geoff York, of Polar Bear International, a conservation group, appears to be corroborated in the Canadian study. "Individual bears in any given year or place will find ways to utilise novel or unpredictable food sources to their benefit," he says. Even with their ability to find replacement sources of food, Dr York remains less than optimistic, particularly given the generally worse health and smaller size of polar bears that have spent longer periods in areas where there was adequate access to terrestrial foods. "What the study says it that there is currently no evidence that these terrestrial sources will offset energetic losses from traditional sea ice prey," he says. While the third study, this one produced by the Wildlife Management Advisory Council, which represents indigenous hunters, is careful to note that changes are occurring to polar-bear habitat, it takes a more cautious tack about the impact of global warming. "There has always been significant annual variation in sea-ice conditions and hence in local abundance, distribution and condition of polar bears and their primary prey," the organistion writes. Interviews with Inuvialuit hunters in northern Canada compiled for the study, 'A Polar Bear Traditional Knowledge Study', would seem to indicate that population and the health of individual bears are both stable. They also reveal that bears tend not to be as large or as fatty as those shot in the 1980s. That might sound like good news for health-conscious humans, but for polar bears it may be an unnerving sign. Original source :http://arcticjournal.com/culture/1485/growing-polar-bear-taste-land-food-worries-scientists   *This image is copyright of its original author An adult Polar bear has just killed White-Beaked Dolphin on Svalbard. This is a behaviour no scientist has ever experienced on Svalbard before. White-Beaked Dolphins usually only visit Svalbard in the summer months, and they have never been seen so far north, so early during spring before.  *This image is copyright of its original author Scientist did this amazing discovery in april 2014, and later during the summer the scientist got in tips about several other carcasses of white-beaked dolphins. Its asumed that they catch the Dolphins on the sea-ice. A white-beaked dolphin doesn`t make much of a meal for a polar bear. And seals will still be their highest priored prey, but they can make a big difference for an individual during the toughest months of the year.  *This image is copyright of its original author The Polar bear stading next to its prey, and the hole in the ice where it probably made the kill.  *This image is copyright of its original author |
| Users browsing this thread: |
| 1 Guest(s) |