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Facts about Animals that are Herbivores for Kids

Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory usually refers to animals eating plants; fungi, bacteria and protists that feed on living plants are usually termed plant pathogens (plant diseases),and microbes that feed on dead plants are saprotrophs.

  • A herbivore is not the same as a vegetarian, a human who voluntarily undertakes a primarily herbivorous diet.
  • Herbivora is derived from the Latin herba meaning a small plant or herb, and vora, from vorare, to eat or devour.
  • Our understanding of herbivory in geological time comes from three sources: fossilized plants, which may preserve evidence of defence (such as spines), or herbivory-related damage; the observation of plant debris in fossilised animal faeces; and the construction of herbivore mouthparts.
  • Insects fed on the spores of early Devonian plants, and the Rhynie chert also provides evidence that organisms fed on plants using a “pierce and suck” technique.
  • Herbivory among terrestrial vertebrates (tetrapods) came much later.
  • While amphibians continued to feed on fish and later insects, reptiles began exploring two new food types, tetrapods (carnivory), and later, plants (herbivory).
  • Hole feeding and skeletonisation are recorded in the early Permian, with surface fluid feeding evolving by the end of that period.
  • Another stage of herbivore evolution is characterized by the evolution of tetrapod herbivores, with the first appearance in the fossil record near the Permio-Carboniferous boundary approximately 300 MYA.
  • Herbivores form an important link in the food chain as they consume plants in order to receive the carbohydrates produced by a plant from photosynthesis.
  • When prey (plants) are numerous their predators (herbivores) increase in numbers, reducing the prey population, which in turn causes predator number to decline.
  • This stabilizing dynamic plays an especially important role for specialist herbivores that feed on one species of plant and prevents these specialists from wiping out their food source.
  • Prey defenses also help stabilize predator-prey dynamic, and for more information on these relationships see the section on Plant Defenses.
  • Keystone herbivores keep vegetation populations in check and allow for a greater diversity of both herbivores and plants.
  • Animals that are time limited, meaning they have a limited amount of time to consume the food they need, use a feeding strategy of grazing and browsing, while those animals that are resource limited, meaning that they are limited in the type of food they eat, use a selective feeding strategy.
  • This model assesses both individual movement, such as animal behavior while looking for food, and distribution within a habitat, such as dynamics at the population and community level.
  • Therefore, according to the Holling’s disk equation, the herbivore in the sparse forest would be more efficient at eating than the herbivore in the dense forest Marginal Value Theorem describes the balance between eating all the food in a patch for immediate energy, or moving to a new patch and leaving the plants in the first patch to regenerate for future use.
  • This can occur via avoidance in space or time, physical defenses, or chemical defenses.
  • Herbivore modification is when various adaptations to body or digestive systems of the herbivore allow them to overcome plant defenses.
  • This might include detoxifying secondary metabolites, sequestering toxins unaltered, or avoiding toxins, such as through the production of large amounts of saliva to reduce effectiveness of defenses.