Grizzly bears, also known as silvertip bears or North American brown bears, are a subspecies of brown bear commonly found in the northern reaches of western North America. Grizzly bears are a large animal with an adult bear capable of reaching 360 kg (790 lbs) in weight and more than 2 m (6.5 ft) in height. Grizzly bears are known for their sometimes aggressive interaction with humans, especially where a mother is protecting her young. The grizzly bear was once found from Alaska right through to Mexico, but today cover only half of their former range. Let’s find out what led to this decline and why the grizzly bear is now listed as an endangered species.
Why are grizzly bears endangered?
There are many reasons that this subspecies is listed as an endangered animal. This first of these is due to the low reproductive rate of the grizzly bear. In fact, this species has one of the lowest reproductive rate of any mammal in North America. This is due to the late sexual maturity of the bear and also because the rate of miscarriage is quite high. Mothers will not mate again for anytime between two and five years after giving birth. The reduction in population has also led to inbreeding and a lack of genetic diversity, which further threatens smaller populations of this bear.
Grizzly bears are also at threat from habitat loss due to logging and deforestation for farming or other human uses. New roads also cause problems because they form boundaries and prevent the many subspecies from interacting with each other, which decreases genetic diversity. Human interactions increase as their habitat is reduced and this further endangers the bears. Some bears become accustomed to humans and begin to rely on them for food. These animals are known as “problem bears” and are removed or killed to protect people.
Grizzly bears have been hunted by humans for hundreds of years and it is estimated that this has had the most devastating effect on the population of this animal. Although hunting is controlled or restricted in some areas, it is still part of the reason that the population of grizzly bears is in decline. Trophy hunting also causes an imbalance in the male to female ratio because hunters prefer the larger male members of the species.
The main efforts for conserving this species revolve around protecting the bears from hunting and loss of habitat. There are a number of grizzly bear sanctuaries that are designed to protect this species.