I believe they do have a community.
They live in groups.
Polar bears are solitary animals and do not live in groups.
They do have a community, however, that interacts and will "aggregate" for short periods for specific reasons and, of course, during the breeding cycles. For an in-depth discussion and definitions of different animal aggregates, see also the related links for one specific study, among many, on the general topic.
An additional link below in the related links section is to the SeaWorld.org information about the polar bear, which contains facts about their behavior that are consistent with other scientific sources. This information comes from long term research and observation about their behavior and habits. In it, and the other scientific sources available, are explanations that they, "...are basically solitary. Usually, only two social units exist," for short term interactions:
In April and May, polar bears aggregate for breeding, usually on the sea ice near the best seal hunting areas. It is also at this time when aggression between males has been observed (when one attempts to steal food caught by another, or when fighting over a breeding female), otherwise, they are not characterized as "territorial".
Besides the routine short term gatherings mentioned above, groupings can also be observed for large scale opportunistic feedings while they exist, such as at dump sites or around a large whale carcass. This is usually in the Hudson Bay area and other southern regions, where polar bears may aggregate on land during the ice-free summer and autumn seasons.
Biotic things in the community are living things. Polar bears mostly interact with them by killing and eating them. These can be fish, bacteria, and germs.
mating, rivalry, catching food (e.g. seals, exc...), saving young from predators (e.g.hawks, large birds, exc....) and more
No, polar bears are solitary animals except for a mother with cubs.
Eukarya
They haven't. Polar bears are now a threatened species. If the polar ice cap goes, then so do the polar bears, as they rely on oceanic ice to secure their food.
there are no different sorts of polar bears, like there are different sorts of cats. There are only the stages of life a polar bear goes through, from cub to adult.
polar bears are related to bears.
Polar bears do.
They reproduce.
POLAR BEARS Polar bears actually grow pretty fast.
community
Polar bears are bears
Polar bears are mammals.
humans are polar bears
A sleuth or a sloth of bears