WHERE WILL THE POLAR BEARS GO?
Splash! A polar bear jumps off a cracking ice floe and swims to another nearby. Crack! This ice floe breaks also, making him crash into the water once again. Steam and water droplets blow from the polar bear’s nose as he lifts his big white head out of the icy water.
He swims on to three other floating ice masses before he finds a solid one large enough to support his massive weight. Eventually, however, he will be forced inland like so many other bears because of melting ice.
By comparison, this bear is lucky. Polar bears, typically strong swimmers, are drowning in increasing numbers because more and more are being stranded out at sea. The sea ice cover of the Arctic, the polar bears’ natural and only habitat, is shrinking.
Warmer temperatures are causing the ice to melt unusually early in the season and in greater proportions. The Canadian Wildlife Service reports that the average winter temperatures in the Canadian Arctic have increased three to four degrees over the last 50 years.
In the Hudson Bay, ice is melting an average of two and a half weeks earlier than in the mid-1970s, which many scientists believe is due to global warming. Polar bears in this region rely on the ice coverage in the winter and spring in order to hunt ringed seals, which are further out to sea.
The shrinking ice cover significantly shortens the bears’ hunting season. During this time they must build up their fat stores to survive their nomadic hibernation through the long winter. Studies have shown that the bears are now coming to shore, on average, 15 percent lighter than they were 20 years ago. In addition, the Hudson Bay polar bear population has decreased by 22 percent, from 1,194 to 935, since 1987.
In Alaska, the summer thaw of 2004 was much more drastic, with the ice retreating in some areas as much as 200 miles. This left polar bears stranded out in the open ocean. Many drowned while trying to make it back to land. Though strong swimmers that can often swim 60 or even 100 miles at a time, they can’t swim 200 miles.
What is to become of the polar bear? Sadly, there is no other suitable habitat for them. If the polar ice cap melts, polar bears may indeed face extinction. Scientists and conservationists are duly concerned. Several conservation groups filed a petition in 2006 with the U.S. Fish and Wildlife Service to list the polar bear as a threatened species under the Endangered Species Act (ESA).
Protection under the ESA means that at least the bear’s habitat in the United States is protected from human activities like oil and gas development. This may not stop the melting of their ice habitat, but it will certainly bring awareness to their plight, and is a step in the right direction.
Global Warming: More Information
Carbon dioxide and other naturally occurring gases help to keep our planet warm and habitable. But too much of a good thing can sometimes be a bad thing. Specifically, increases in carbon dioxide from coal, auto emissions, factories, and other sources of pollution have created a much heavier layer in the earth’s atmosphere than we need. The result is that the sun’s ultraviolet rays can enter, but cannot be reflected back into space. This heavy “blanket” warms the air, water, and land below, melting the polar ice sheets in the Arctic and other glaciers around the world.
When more water and land become exposed, the earth absorbs more heat. Radiation from the sun that was once reflected back into space by glaciers and sea ice is now being absorbed by the newly exposed dark surfaces of the land and ocean.
This warming trend is impacting the entire planet. One Greenland glacier is melting at a rate of 9 miles per year. That’s enough water to fill Lake Erie, the tenth largest lake in the world, each year! In Siberia, a 386,000-square-mile expanse of permafrost that has been frozen for an estimated 11,000 years is now thawing. Permafrost is essentially a frozen peat bog, which is made up of dead and decayed plants. The melting of the bog is significant because peat generates methane, a greenhouse gas that is 20 times more potent than carbon dioxide.
Also impacted are plant, insect, and animal populations. In Southern California, the beetle population exploded in 2005, the hottest year on record. This population boom led to the death of hundreds of evergreen trees, which in turn provided hundreds of acres of fuel for the devastating wildfires that year.
Each of these examples taken by themselves is startling. Taken together, with all other environmental impacts not mentioned here, the idea of global warming can be downright alarming. However, there are actions we can all take to help minimize our individual impact on the earth’s surface.
Tuesday 1 January 2008
Reading Materials for Teens I
THE SWEETEST PET
If you’re a pet owner, I bet you’d say you have the nicest animal in the world. But some animal lovers might disagree with you. These people own sugar gliders; and for them, no animal is sweeter.
The sugar glider is a marsupial. The females have pouches on the outside of their bodies. These pouches are homes to their newborns, called joeys. The joeys live inside for weeks or months until they mature. When they are fully developed, they crawl out of the pouch. There are about 200 species of marsupials.
The sugar glider belongs to the same marsupial group as kangaroos and possums.
Sugar gliders look like small, gray squirrels with dark streaks on their faces. A dark stripe runs from their nose to the tip of their tail. Adult gliders weigh between 4-6 ounces. They measure about 12 inches from their nose to their tail.
These marsupials are nocturnal, meaning they are active at night. They have large, round eyes which help them see in the dark. Sugar gliders live in eastern Australia, New Guinea, and Tasmania. In the wild, sugar gliders can live up to 9 years. When raised in captivity, they can reach 12-14 years of age.
As you might guess, sugar gliders got the first part of their name because they have a sweet tooth. Their diet consists of nectar and sap, as well as leaves, petals, and insects. One of their favorite foods is the sap that flows from the manna gum. The manna gum is a tree native to the eastern states of Australia.
The other part of the name—glider—describes their ability to soar through the air. Sugar gliders possess a loose skin membrane that’s attached to the sides of their bodies between the wrists and the ankles. When sugar gliders take off from a tree branch, they spread their limbs. This tightens the membrane, which allows them to glide up to 150 feet!
Sugar gliders are highly social creatures. They live in communities of nests with up to seven adults and their young. Communities of sugar gliders rarely fight. That’s because the males mark family members with a scent to identify each other. In fact, sugar gliders raised as pets will also mark their owner, so that the owner becomes “theirs.”
Though sugar gliders can be owned as pets, there are some things you need to know. Sugar gliders are classified as exotic pets. Before buying one, check your state and city regulations. Also, the cost of these pets runs from $99.00 - $200.00, not including the setup. A cage, exercise wheel, climbing ladders, and a nesting box for sleeping can add up to hundreds of dollars. Moreover, sugar gliders need to have a special diet that may not be found at some pet stores. Failure to provide the proper diet or housing may result in medical problems for a glider.
Veterinarians encourage neutering males to prevent aggressive behavior. Retailers suggest buying sugar gliders in pairs because they like company. If an owner is unable to purchase two, he must be willing to spend time with it. The International Sugar Glider Association recommends that adults always supervise while children are playing with these fragile creatures.
Despite the challenges of ownership, sugar gliders make wonderful pets. They bond easily with people and love to be cuddled. People can carry them in a pouch or a shirt pocket.
With proper care, these marsupials can have a good long life. Owners acknowledge that sugar gliders have a sweet tooth, but that’s not the only reason they make the sweetest pet in the world.
If you’re a pet owner, I bet you’d say you have the nicest animal in the world. But some animal lovers might disagree with you. These people own sugar gliders; and for them, no animal is sweeter.
The sugar glider is a marsupial. The females have pouches on the outside of their bodies. These pouches are homes to their newborns, called joeys. The joeys live inside for weeks or months until they mature. When they are fully developed, they crawl out of the pouch. There are about 200 species of marsupials.
The sugar glider belongs to the same marsupial group as kangaroos and possums.
Sugar gliders look like small, gray squirrels with dark streaks on their faces. A dark stripe runs from their nose to the tip of their tail. Adult gliders weigh between 4-6 ounces. They measure about 12 inches from their nose to their tail.
These marsupials are nocturnal, meaning they are active at night. They have large, round eyes which help them see in the dark. Sugar gliders live in eastern Australia, New Guinea, and Tasmania. In the wild, sugar gliders can live up to 9 years. When raised in captivity, they can reach 12-14 years of age.
As you might guess, sugar gliders got the first part of their name because they have a sweet tooth. Their diet consists of nectar and sap, as well as leaves, petals, and insects. One of their favorite foods is the sap that flows from the manna gum. The manna gum is a tree native to the eastern states of Australia.
The other part of the name—glider—describes their ability to soar through the air. Sugar gliders possess a loose skin membrane that’s attached to the sides of their bodies between the wrists and the ankles. When sugar gliders take off from a tree branch, they spread their limbs. This tightens the membrane, which allows them to glide up to 150 feet!
Sugar gliders are highly social creatures. They live in communities of nests with up to seven adults and their young. Communities of sugar gliders rarely fight. That’s because the males mark family members with a scent to identify each other. In fact, sugar gliders raised as pets will also mark their owner, so that the owner becomes “theirs.”
Though sugar gliders can be owned as pets, there are some things you need to know. Sugar gliders are classified as exotic pets. Before buying one, check your state and city regulations. Also, the cost of these pets runs from $99.00 - $200.00, not including the setup. A cage, exercise wheel, climbing ladders, and a nesting box for sleeping can add up to hundreds of dollars. Moreover, sugar gliders need to have a special diet that may not be found at some pet stores. Failure to provide the proper diet or housing may result in medical problems for a glider.
Veterinarians encourage neutering males to prevent aggressive behavior. Retailers suggest buying sugar gliders in pairs because they like company. If an owner is unable to purchase two, he must be willing to spend time with it. The International Sugar Glider Association recommends that adults always supervise while children are playing with these fragile creatures.
Despite the challenges of ownership, sugar gliders make wonderful pets. They bond easily with people and love to be cuddled. People can carry them in a pouch or a shirt pocket.
With proper care, these marsupials can have a good long life. Owners acknowledge that sugar gliders have a sweet tooth, but that’s not the only reason they make the sweetest pet in the world.
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