The owl and the eagle are examples of tertiary consumers that live in the desert. Other desert animals, such as the dingo and gila monster, are also considered tertiary consumers because they eat other carnivores. Most of these animals are small, though there are a few larger tertiary consumers.
Animals in an ecosystem can be labeled according to where they get their energy. Plants are producers that make their own energy, and the plants are then consumed by primary consumers. The primary consumers are preyed upon by secondary consumers, which are then preyed upon by tertiary consumers.
These categories of organisms are known as trophic levels. The number of trophic levels in an ecosystem can continue past the tertiary level, though the number of levels is limited by the availability of resources. A listing of organisms that consume each other by trophic level is called a food chain. Decomposers and detritivores are the last link in any food chain. These organisms eat the remains of plants and animals.
Most of the plants and animals in a desert ecosystem do not need to feed very often and require little water. Many are nocturnal, preferring to hunt for food and water in the cooler night time temperatures.