Buenos Aires, Argentina, South America – Winner, the last remaining polar bear at Buenos Aires Zoo, has pass away due to overheating from the summer like temperatures. Snowy winter for the northern hemisphere, means summer like temperatures in the southern hemisphere. The climate in Buenos Aires is considered humid, subtropical. The warmest time of year there is in December – January, running an average of 77-88 degrees (Fahrenheit), but can go as high as 113.
A polar bear can overheat in prolonged exposure to temperatures above 50 degrees (Fahrenheit). They are not meant to acclimatize to various environments. They are physiologically build to live in Arctic climates, with their insulating subcutaneous layer of blubber and dense pigment-less fur. The tell-tell white coat may yellow with age, but polar bears do not shed their coats, or endure a color change for seasonal camouflage. Arctic Foxes, hares, and ermines change from brown to white beginning in September in the Arctic Circle. Polar bears stay consistently white year-round.
They are considered the largest terrestrial carnivores, consisting on a natural diet of seals, walruses, and scavenge form abandoned whale carcasses. Polar bears are apex predators, and excellent swimmers, which means they exist top of the food chain when in their indigenous environment.
They are not considered as aggressive or territorial as grizzly bears. But they are not to be provoked. Polar bears live up to 20 years, but can exceed that when in captivity. In the wild, polar bears likely die from poaching, injury from fights or accidents, or become too weak to hunt and starve. It has been illegal since the 1950′s to hunt polar bears.
As of 2008 polar bears are classified as a ‘threated species’ under the Endangers Species Act, an environmental law enacted in 1973, established to protect critically imperiled species from extinction. This is due to the extreme environmental fluctuations at are occurring to their natural habitat; melting ice sheets of the Arctic.
The Washington Post proposes one way to ensure the species survives is to place more of them in captivity, in zoos. With heat-trapping greenhouse gas emissions caused by burning fossil fuel are making the Arctic warm twice as fast as lower latitudes, and Arctic summer sea ice could disappear by 2030. Therefore, the polar bear would no longer have a home.
As ideal as it would be to simply house an animal in captivity in order to save it, sometimes it has the opposite effect. The Daily Mail reports that Winner, a popular attraction for the Buenos Aires Zoo, died from hyperthermia, or heat stroke. His body failed to thermo-regulate, causing an excessive amount of heat to be absorbed. If left untreated heat stroke can lead to damage of the brain, heart, and kidneys, increasing the likely hood of death. In contrast, hypothermia is when the core temperature of the body drops below a certain temperature, inhibiting normal metabolism and function. Hyperthermia differs from fever in that the body’s temperature homeostatic set point remains unchanged. Homeostasis is the body’s mechanism for maintaining a healthy internal balance of temperature and pH. In Winner’s case, he could not tolerate the hot weather exposure, and suffered heat stroke. It was also surmised he may have been previously distressed by the recent Christmas Eve fireworks.