Polar bears are the largest land carnivores in the world. Polar bears are marine mammals, and spend much of their time on Arctic sea ice. Many adaptations make polar bears uniquely suited to life in icy habitats and Polar bears feed almost exclusively on ringed seals and bearded seals. They are also known to eat walrus, beluga whale and bowhead whale carcasses, birds’ eggs, and (rarely) vegetation. Polar bears travel great distances in search of prey. (defender,2017). Polar bears succeed in catching their prey in only 2 percent of their attempts. (LiveSCI, 2014).

This high-calorie meal helps the bears build up fat reserves, which keep polar bears healthy between feedings and help maintain their body temperature. According to PBS Nature, polar
Ecological Importance

Over thousands of years, polar bears have also been an important part of the cultures and economies of Arctic peoples. Polar bears depend on sea ice for their existence and are directly impacted by climate change—serving as an important indicator species.

The loss of sea ice habitat from climate change is the biggest threat to the survival of polar bears. Other key threats include polar bear-human conflicts, unsustainable hunting and industrial impacts. Climate change is also resulting in more habitat fragmentation. As Arctic ice melts, polar bears are affected by increased shipping

activities and a rise in opportunities for oil and gas development. (WWF,2017)

As the Climate Changes

Understanding causes and consequences of climate-related shifts in ecosystem functioning, as well as the role of focal species in these processes, is currently a dominant theme in ecology. In the Arctic, temperature has increased at a rate two to three times faster than at southerly latitudes (Post et al.,
The decrease in the extent of sea ice is on the order of 5% per decade in the Arctic (Liu et al., 2004; Serreze et al., 2007). One of the species directly affected by global warming is the polar bear (Ursus maritimus) whose life history is closely tied to sea ice (Lunn and Stirling, 1985).

Evidence is accumulating that polar bears are suffering from a warming climate and associated loss of sea ice habitat .It is expected that continued sea ice reductions will severely affect polar bear populations (Durner et al., 2009), which will force them into terrestrial ecosystems during the summer months in search of food (Stempniewicz,1993; al., Hanssen et al., 2013 )

In the last 30 years, bears have increased the amount of time they are on land by almost 30 days - staying another day longer each year .That means the bears are coming ashore to face food shortages

before they have stored enough fat to last through the season."The bears just run out of energy," The longer summer fasting