Herbivores

• Deer are typically herbivores, consuming only vegetation.Photos.com/Photos.com/Getty Images
  
  Herbivores are organisms that feed on vegetation as their source of nutrition. Common examples of food sources include flowers, grasses, stems and fruits. Because herbivorous predators derive their energy from only plants, they must consume large amounts of vegetation in order to maintain their optimal body function. In terms of the overall food chain of a given ecosystem, herbivores may become the main food source for other larger predators. Examples of herbivorous predators include deer, rabbits, squirrels and cattle.
  
  

Omnivores

• Bears eat both fruits and meat.Jupiterimages/Photos.com/Getty Images
  
  Omnivores are organisms that feed on both plants and animals for their sources of nutrition. Omnivorous predators are largely opportunistic, eating whatever type of food source is most readily available. As a consequence of their diverse diet, omnivores vary according to species and location. In addition, their flexibility of diet allows omnivores to survive in a wide array of environments and conditions. Common examples of omnivorous predators include humans, bears, pigs and raccoons.
  
  

Diet Advantages

• Vegetation sources are often plentiful for herbivores.Photos.com/Photos.com/Getty Images
  
  Herbivorous and omnivorous predators possess unique biological advantages based on their choice of diet. Due to the larger, relative availability of vegetation in most environments, herbivorous predators usually have plenty of food to feed on. However, the low nutrition content of plants forces herbivores to consume large amounts each day. On the other hand, omnivores can eat both animals and plants, enabling them greater mobility and adaptability over varying conditions.
  
  

Adaptations

• Vultures exemplify scavenger behaviorJupiterimages/Photos.com/Getty Images
  
  Evolutionarily, both herbivores and omnivores have adapted to their prey over thousands of years. Most herbivorous predators have specialized bacteria within their digestive system to break down cellulose and other tough plant material. Cows, for instance, have four stomachs to ensure the efficient processing of vegetation. Omnivores have evolved specifically to adapt to the available food sources. Scavengers feed on only dead meat; carnivores can hunt down other animals; other omnivores specialize in stealing animal eggs.