Koalas need nitrogen to make energy, though they move very slowly. Without this valuable mineral they would simply not survive. Eucalyptus trees also contain toxins, a potential death threat to the animal.
Eight species of eucalyptus were tested. It was found that koalas stayed away from trees carrying toxins and were attracted to those high in nitrogen. They obviously know what is good them. The search for food dominates their lives.
If this identification of superior food is true for koalas it must be the case for other animals. They are intrinsically guided to sources of higher quality food. Dogs for example do know which type of grass to eat to solve a health problem. It is unusual for dogs to eat grass, but sometimes they do.
If good food is scarce which it is in Australia, it is logical that sensory systems of animals would evolve to identify sources of better nutrition. In the future, environmentalists should examine the quality of food in a habitat before re-introducing endangered animals. The carrying capacity of the environment affects its carrying capacity.
Science by Ty Buchanan