Polar bears (Ursus maritimus) are fascinating marine mammals known for their striking white fur and impressive adaptations to life in the Arctic. Here are some key points about them:

### Habitat
- **Range**: Polar bears are primarily found in the Arctic regions, including areas of Canada, Alaska (USA), Greenland, Norway, and Russia.
- **Environment**: They thrive on sea ice, which they use as a platform for hunting seals, their primary prey.

### Physical Characteristics
- **Size**: Adult polar bears can weigh between 900 to 1,600 pounds (410 to 720 kg) and can stand about 8 to 10 feet (2.4 to 3 meters) tall when on their hind legs.
- **Fur and Skin**: Their fur appears white but is actually transparent and hollow, helping to reflect light. Underneath, they have black skin, which absorbs sunlight to help keep them warm.

### Diet and Hunting
- **Diet**: They primarily hunt seals, especially ringed and bearded seals. They are classified as carnivorous, but they may also scavenge and occasionally consume other food sources, including carcasses or vegetation.
- **Hunting Technique**: Polar bears are skilled hunters, often using a method called "still-hunting," where they wait by seal breathing holes or along the edge of sea ice for seals to surface.

### Behavior and Adaptations
- **Swimming**: Polar bears are excellent swimmers and can cover long distances in the water, using their large front paws to paddle.
- **Adaptations**: Their thick layer of blubber and fur provides insulation in extremely cold temperatures, while their keen sense of smell helps them detect seals nearly a mile away.

### Reproduction
- **Mating**: Breeding occurs in the spring, and after a gestation period of about eight months, female polar bears typically give birth to one to three cubs in a den during the winter.
- **Cubs**: Cubs are born blind and helpless, relying completely on their mother's milk and warmth. They usually stay with their mother for about two to three years.

### Conservation Status
- **Threats**: Polar bears are classified as vulnerable due to climate change, which is causing sea ice loss. Other threats include oil and gas exploration, shipping traffic, and pollution.
- **Conservation Efforts**: Various organizations and governments are working to protect their habitats and mitigate the impacts of climate change.

### Cultural Significance
- Polar bears hold significant cultural importance for indigenous Arctic communities and are often featured in folklore, art, and conservation campaigns.

Polar bears are not just iconic symbols of the Arctic but also indicators of the health of the marine environment, making their conservation critical for the broader ecosystem.