Polar Bear World Of Ice Mac OS

Polar bears are listed under a variety of classifications depending on international, national, and regional regulations. Internationally, they are listed as a vulnerable species by the IUCN. In Russia, polar bears are classified as a Red Data Book species, a listing that includes animals considered rare or endangered. The WWF Polar Bear USB Drive is compatible with Windows 7, XP, Vista and Mac OS X, prices start at $9.95 for the 1GB version up to $42.95 for the 16GB version, they are available now from Amazon. This polar bear is hungry and is breaking through the ice looking for food. This clip was captured by Polar Bears International on their Tundra Buggy on.

A polar bear’s life seems simple enough: eat seals, mate, and raise cubs. But a recent study shows some subpopulations of polar bears are struggling to complete these essential tasks because of declining concentrations of Arctic sea ice.

The Arctic sea ice cap is a large area of frozen seawater floating on top of the Arctic Ocean and its surrounding seas and straits. For polar bears, the sea ice is a crucial platform for life. They use the ice to travel long distances to new areas. They hunt for seals by finding their dens or sitting next to gaps in the ice, waiting for the unsuspecting prey to pop up. Sometimes, pregnant females dig in the sea ice to create maternity dens, where they give birth and take care of their cubs.

In recent decades though, this critical habitat has been shrinking. Sea ice concentrations have declined by 13 percent each decade since 1979 due to increasing global temperatures. Arctic regions have warmed twice as fast as the rest of the world, so seasonal sea ice is also forming later in the fall and breaking up earlier in the spring.

“We know that sea ice, which is where the bears need to be, is decreasing very rapidly,” said Kristin Laidre, an Arctic ecologist at the University of Washington. “When there’s no sea ice platform, the bears end up moving onto land with no or minimal access to food. Our research looked at how these changes affect their body condition and reproduction.”

In a new study published in Ecological Applications, Laidre and her colleagues described how declining sea ice concentrations are affecting the behavior, health, and reproductive success of polar bears. Using field observations and remote sensing, the study showed that polar bears are spending more time on land and are fasting for longer periods of time. Mother bears are also producing smaller cub litters, which the team projected will continue to decline for the next three polar bear generations.

July 15, 1993 - July 15, 2013PNG

“Climate-induced changes in the Arctic are affecting polar bears,” said Laidre, who was the main author of the study. “They are an icon of climate change, but they’re also an early indicator of climate change because they are so dependent on sea ice.”

The team specifically studied a subpopulation of bears that depend on seasonal sea ice in Baffin Bay. The team tracked polar bear movements across the bay over the past two decades. The map at the top of this page shows the movements of 43 tagged adult females from 1991-1997 (left) and 38 adult females from 2009-2015 (right).

They found that most bears follow the seasonal growth and recession of sea ice to end up on Baffin Island in the fall, when sea ice is usually at its lowest extent. They usually wait on Baffin Island until the ice forms again so they can leave. On average, the bears are spending 30 more days on land now than they did in the 1990s. Laidre says that is because the ice is retreating earlier and there has been more open water in recent summers.

The maps above show the difference in sea ice extent around Baffin Bay on July 15, 1993 and July 15, 2013. The satellite data are processed by NASA-funded scientists and stored at the National Snow and Ice Data Center. The graph below shows the onshore arrival and departure of polar bears on Baffin Island relative to dates of sea ice advance and retreat. Sea ice has been breaking up earlier in the spring over the years (green) and is forming later in the fall (blue).


1979 - 2017

“That’s important because when the bears are on land, they do not hunt seals,” said Laidre. “They have the ability to fast, but if they don’t eat for longer periods, they get thinner. This can affect their overall health and reproductive success.”

To assess polar bear health, the team quantified the condition of bears by assessing their level of fatness after sedating them or inspecting them visually from the air. Laidre and colleagues classified fatness on a scale of 1 to 5. Results showed the bears’ body condition was linked with sea ice availability in the current and previous year.

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Cub litter size was also affected by the body condition of the mothers and by sea-ice availability. The researchers found larger litter sizes when the mothers were in a good body condition and when spring breakup occurred later in the year, meaning bears had more time on the sea ice in spring to find food.

Then finally, the team used mathematical models to forecast future reproductive success. The model took into account the relationship between sea-ice availability and the bears’ body fat and variable litter sizes. They projected that the normal cub litter size of two may decrease within the next three polar bear generations (37 years), mainly due to the projected decline of sea ice in the coming decades.

The results of the study were not necessarily surprising for Laidre, who has been studying the changes in the Arctic ecosystem for the past 20 years. She says it is well known that changes in the climate are having a negative effect on polar bears. Even if greenhouse gases were curbed immediately, sea ice would likely continue to decline for several decades because large-scale changes take a long time to propagate through Earth’s climate system.

In the meantime, Laidre hopes this study’s information will be used to further understand the impacts of sea ice loss on the species.

“Polar bears are a harbinger for the future,” said Laidre. “The changes we document here are going to affect everyone around the globe.”

NASA Earth Observatory images by Joshua Stevens, using data courtesy of Kristin Laidre and Harry Stern at the University of Washington, and sea ice data from the National Snow & Ice Data Center (NSIDC). Story by Kasha Patel.

By Paul Greenberg, Safina Center Fellow

The money shot of climate change is without doubt that of a polar bear stranded on a tiny island of ice, seemingly hopelessly adrift while the world around melts into oblivion. But as we pulled into an anchorage off Spitsbergen Island in the territory known as Svalbard this weekend, I came to understand that this iconic image tells a very different story about the way bears live. In fact, if everything is going right with climate and bear habitat, polar bears want to be floating on ice. Fast ice, that is ice that fringes the edge of dry land on one side and more permanent sea ice on the other is prime hunting ground of the polar bear. It’s very movement and permeability is a way for this energy-intensive animal to conserve its fuel while searching for its next meal.

That next meal is, more often than not, a seal, a ringed seal perhaps or a harp or a bearded. Seals spend about 80% of their lives in the water. That 20% of the time on land is when they are most vulnerable to bears. Bears know this very well. They also know that seals will need to exit their preferred element to breath from time to time. So a bear will sit, sometimes for hours near the exit hole on fast ice, waiting for a blubbery seal to emerge and take what the polar bear hopes will be its last breath. For a polar bear, a seal is about food and water–bears rarely have access to freshwater and so the liquid contained in seal blubber hydrates them at the same time that it nourishes. For this reason bears usually leave the meat on a seal to the birds.

The seal-on-ice hunting strategy can be pretty successful but once a seal has been eaten or spooked from its hole, the bear has to move on to a new one. That’s where the ice becomes essential. Every new sheet of ice is new territory when it comes to hunting for a new seal breathing hole spot. Polar bears’ extra wide feet allows these massive animals to spread their weight out, allowing them to pad around on thin, as well as thick, ice. In this way, the floating ice archipelago of the Arctic Sea brings bears and prey inexorably together, a flow of energy from animal to animal every bit as cyclical as the tides and the winds.

Svalbard is one of the polar beariest places in the world, home to about 3,000 animals altogether (there are an estimated 25,000 polar bears total, worldwide). And so it was no surprise that we sighted one right away. “Bear,” one of the passengers said nonchalantly, peering through the lens of his long-range Nikon. Soon radios were abuzz and a ring of Zodiacs formed around the roaming animal. Leisurely, the roughly 400-pound female (or perhaps juvenile male) loped around the edge of the ice that extended like a shelf into the bay. I managed to snap a quick picture with my iPhone camera:

Fortunately Cian Ryan, an amateur wildlife photographer was aboard my Zodiac with a serious lens, affording a closer look.

Later we could see another bear’s tracks, as large as two human hands hugging the shore, looking for a passageway across the bay.

Polar Bear World Of Ice Mac Os X

May is a precious make-or-break month for polar bears. It is when mothers must either hunt for their cubs or double their body weight so that they can bring a fetus to term. Fast ice lets this happen but that fast ice diminishes as each week passes, as the summer sun grows more intense. By August the ice has melted away, and the chance of snaring a seal are minimal. By the time the tundra is blooming with Arctic flowers and all other creatures celebrate life’s summertime bonanza, polar bears on Svalbard will hunker down in the muck and wait. Aside from the occasional egg stolen from a bird’s nest here and there, they are slowly starving, stuck by summertime weather when the mass transit system of ice goes on strike. It’s a tricky time for bears. If they time it wrong they will burn through their fat reserves, and by October they will be too tired to hunt when the ice finally forms again….

Polar Bear Ice Machine

Which is why the vanishing ice of the Arctic is so concerning.

Why Polar Bears Need Ice

In the graphic above, note that the biggest loss of ice isn’t the more central thick ice at the poles but the fast-moving sea ice on its fringes. Thicker, older ice is of little use to seals and bears. That kind of ice doesn’t afford breathing holes for seals nor hunting grounds for their principle predators. That this collapse of habitat should come now is particularly heartbreaking. Polar bears are in fact in the middle of a major resurgence. For most of the 20th century they were hunted hard by trappers using “kill boxes” in which a piece of seal meat was affixed to a string which in turn was tethered to a hidden gun’s trigger; a trap that in effect tricked bears into shooting themselves. Today the kill boxes are gone. Bears are now much better protected in Svalbard and much of the Arctic. In fact, because both trapping and traditional Inuit hunting have declined markedly there are probably more polar bears alive today than in any time since Homo sapiens took up residence in the Arctic. But should we lose that sea ice, that “edge” that gives polar bears their edge, the high numbers of bears could collapse quite quickly, possibly by the middle of this century.

Polar Bear World Of Ice Mac Os 11

That’s life in the Arctic. Gaming a system with very thin profit margins of energy. Margins negotiated by that all-important broker of climate: ice.

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