Polar bears are large carnivorous mammals that live in northern Russia, North America, and the Arctic. They can live on both land and in water, and their diet consists primarily of ringed seals, penguins, and fish. Females give birth to litters of 2-4 cubs every 2-3 years and care for their young for about two years. While the population was only around 10,000 in 1960, there are now approximately 40,000 polar bears worldwide, though they remain threatened by climate change and melting sea ice habitats.