Different organisms play different roles in an ecosystem. One way of looking at an ecological system is by following the pathways taken by energy. Some organisms, such as plants and algae, capture energy from the sun and are called producers. Others are herbivores, capturing their energy by feeding on the producers. In turn, herbivores are preyed upon by meat eaters who may also be preyed upon by other carnivorous types. This food chain is made more complex by decomposers, mainly fungi and bacteria, that gain their energy requirements by breaking down dead plant and animal material.
Most ecosystems are even more complex than this. Scavengers, for
example, fit in between natural or predator-caused deaths of animals on the one hand
and the decomposers on the other. Although many animals will scavenge as opportunity
arises, some have specialized to the point that almost their entire food requirements
are met by this route. A number of birds fit into this role—creatures that act as
nature's garbage processors. An honorable profession, so let's hear it for our
friends, the vultures!
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.