Ask A Scientist
I understand that the polar bear is being placed on the list of species threatened with extinction. How many polar bears were there 100 years ago and what are their reproduction abilities in the wild and captivity?
Asked by: Angel Hoogendoorn
School: Calvin Coolidge Elementary School
Teacher: Mrs. Vercolen
Hobbies/Interests: Skiing, jumping on the trampoline and riding my bike.
Career Interest: Lawyer
Answer from George Catalano
Professor of Mechanical Engineering, Director of t
Turbulence, Fluid Mechanics, Aerodynamics, Environmental Ethics, and Modeling Ecosystems
University of Virginia, Aerospace Engineering, 1977
All things Italian, Creative Arts, Model trains & cars
Wife, Karen, is a registered yoga teacher at Yoga for Everybody at the Orthopedic Associates; lives with 3 Alaskan Malamutes, two more in our hearts
The scientific name for the polar bear is Ursus maritimus. In Latin, "Ursus" means "bear" and "maritimus" means "sea" and thus "Ursus maritimus" can be translated as "bear of the sea." The polar bear is one of eight species of bears around the world. Polar bears have a normal life span of about 25 years for males and 30 for females, although a small number of individuals may live longer. In captivity, there have been a number of individuals that have survived for longer than 40 years of age. The breeding season occurs in spring to early summer. The number of cubs per litter is one or two, rarely three. Younger and older females often have only one cub, while 2 or even 3 cubs may be born to females between the ages of about 8 and 20. As for all mammals, the mortality of cubs is quite high, sometimes exceeding 70%. Cubs typically stay with their mother for the first two years of their lives, but in some areas where the marine ecosystem is less productive they may remain with their mothers for up to almost 5 years. For most parts of their range, females normally mate and gives birth every 3 years. The world population is estimated to be between about 21.500 and 25,000 bears, of which 15,000 or more are in Canada. Polar bears are not evenly distributed throughout the Arctic. Polar bears live in about 19 or so relatively separate populations, of which 14 of those currently recognized are in or shared by Canada. With the recent, dramatic rise in gasoline prices, more attention than ever before has been focused on the huge costs for our society that our present reliance on fossil fuels has generated. Certainly no one is happy with spending $30 or more for 10 gallons of gas. But perhaps there is an even greater cost for our society that perhaps is not quite so obvious though in the long run is potentially much more devastating. There is little debate that our addiction is directly linked to climate change and climate change represents one of the most pervasive threats to our Earth's biodiversity. A recently published study co-authored by the World Wildlife Fund suggests that a quarter of the world's species will be on their way to extinction by 2050 as a result of accelerating climatic changes directly linked to human use of fossil fuels. Of all the plants and animals with whom we share life on Earth, polar bears are set to become one of the most notable and dramatic casualties of global warming unless drastic action is taken now. The impact of climate change is increasingly felt in Arctic regions, where summer sea ice is expected to decrease by 50-100 percent over the next 50-100 years. Dependent upon arctic sea-ice for hunting seals and highly specialized for life in the arctic marine environment, polar bears are predicted to suffer more than a 30 percent population decline in the next 45 years. Recent news articles have stated various extinction timeframes for this majestic creature, and although no one knows for sure when we might see the demise of the species, we do know that without immediate action this species is in great peril. The question becomes not if polar bears will become extinct but how quickly will the extinction happen? The advertisement campaign one oil refinery company uses a Bengal tiger to tout the performance of their gasoline and diesel fuel. Perhaps even more intricately linked to the consumption of fossil fuels is the polar bear. With fossil fuel consumption rising as is the average temperature of the Earth, we may be reduced to watching computer generated images of polar bears much as we watched dinosaurs in Jurassic Park.