Polar bears are the largest carnivorous animals alive being about 2.5-3m in height and weighing about 400-800kg; the females are about half that size. They are found mainly in the Arctic area and in the surrounding landmasses namely Norway, Greenland, Canada, Alaska and Russia. They are closely related to the brown bears that are located in warmer places and as such these polar bears have evolved a special set of characteristics to live in the cold climate (the temperature can drop as low as -45°C) such as thick fur to withstand the cold with a thick blubber layer and being white in colour to be concealed in the snow. They prey mainly on ringed seals found in the area but can also go for eggs, birds and whales.
The loss of polar bears has always been an alarming issue. People have hunted these animals in the past for food, clothing and cultural matters. In the 1500s, overhunting became a major factor in the decline of the bears’ population; coupled with technology, it then became a flourishing business in the 1970s. In this respect, a law was passed in 1973 to halter bear hunting using aircrafts and motorized means. In many countries such as Alaska and Canada, bear hunting is regulated. Some people however do keep to their habits because of traditional beliefs.
Other imminent factors to the decline of the polar bears include intraspecific (between the bears) competition for food and mates; males fighting with females over the cubs’ protection; diseases, the most potent one being the Trichinella roundworm (that lives on the seals and is transferred during feeding which can eventually lead to death of the bears); pollution carried via water and air (when they ingest toxic foodstuff) but most lethal these days is the environmental change that is occurring as a result of climate change.
As a matter of fact, polar bears depend on the sea ice as a bridge to the seals or to cross channels to their homes or find mates. The increasing temperature is causing the ice sheets to melt which then removes the transportation means of the bears. Many of the animals have been found to die of starvation because of the inaccessibility to their food sources. Moreover, more polar bears are seen to wander on land rather than the sea because of the retreating ice areas. In many regions, the dens where the females give birth and look after the youngs are melting and these animals could be subject to secondary effects of climate change as forest fires. In other cases, lack of mates has resulted in females failing to impregnate which further reduces the population size. While studies have shown that it is mostly the new borns, sub adults and older bears that are more at risk to this shift in temperature as compared to the more mature bears, the risk that global warming poses to the polar bears cannot be regarded as minimal since scientists have also proclaimed the polar bears to be “threatened” because of climate change.
In 30 years, the polar ice cap has melted by 20% which is quite alarming because if the present rate continues, the Arctic region will be ice free in 150 years. This will not impact the polar bears only but the other animals adapted to live in the region as well like the ringed seals and the walruses, native people would be devastated and the resulting sea level rise would have worldwide repercussions.