An omnivorous animal is an animal which eats both meat and plants for its food. It is often a hunter which captures prey, but it also eats fruits or other plants which it can digest.
The omnivorous mammals have greater chances of survival, because if there is a sudden shortage of a food source, they can feed from the other group if they are available.
Omnivores are not necessarily predators, if fruits are available, it will not hunt unnecessarily.
All the animals are opportunist and if a meal is easier than another to get, it will choose this one.
The teeth, the digestive system and other characteristics determines if it has the capacity to be eat of the two groups of food. Certain plants will not make the deal, as the grass which is not nutritive enough for them, therefore if it cannot find plants which it can eat, it will hunt for prey.
The bear will eat it's fill of berries, wild fruits and other food easily available, because it must eat a tremendous amount. It will fish salmon when it spawns up the rivers, because the fish are then many and thus easier to capture.
The omnivores are both predator and a prey in the food chain. It is not always equipped with claws, like a carnivorous animal, the primates are an example. They are usually the predatory ones for the animals smaller than them, except if they hunt in groups.
