Both scavengers and detritivores consume dead animals. Scavengers obtain most or all of their sustenance from dead animals, while detritivores often consume a combination of decaying plant and animal material, as well as waste.
Scavengers occupy the third trophic level of their ecosystem, along with omnivores and other carnivores; scavengers are important in nutrient cycling in an ecosystem because they return organic material to the environment. Many scavengers have special adaptations for their lifestyle. Vultures lack feathers on their heads and necks to prevent carrion from fouling their feathers and harboring bacteria. Lammergeiers, or bearded vultures, consume little meat. Instead, most of their diet comes consists of bone marrow. Lammergeiers crack large bones by carrying them to a height and dropping them on rocks. Many scavengers, like hyenas, are also predators that hunt live prey as well as scavenging.
Detritivores and decomposers often feed exclusively on decaying organic material. Like scavengers, they play a vital role in recycling and returning nutrients to an ecosystem. These organisms break down organic material and return nitrogen to the soil. Arthropods like millipedes, earthworms and flies are common detritivores. Detritivores also include fungi, bacteria and some plants. Mushrooms are a common detritivore of mature woodlands.