Digestive System of Amphibians, Reptiles and Birds

C Edward Stevens, North Carolina State University, Raleigh, North Carolina, USA

Published online: April 2001

DOI: 10.1038/npg.els.0001839

The digestive systems of amphibians, reptiles, and birds share many characteristics with those of fish. However, the transition of amphibians from an aquatic to a terrestrial environment, the development of endothermy in birds, and the adoption of a wider range of diets required a number of adaptations.

Keywords: digestion; absorption; bacterial fermentation; herbivores

Figure 1. Gastrointestinal tracts of a toad and salamander. From Stevens and Hume (1995).
Figure 2. Gastrointestinal tracts of a carnivorous caiman and chameleon, omnivorous terrapin, and a herbivorous lizard and tortoise. From Stevens and Hume (1995).
Figure 3. Gastrointestinal tracts of a carnivorous hawk, plant concentrate-feeding budgerigar, omnivorous chicken, and herbivorous grouse, hoatzin, emu and ostrich. From Stevens and Hume (1995).
Figure 4. Relationship between habitat and adaptations of the urinary and gastrointestinal tracts. From Stevens (1977).
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 Further Reading
    book Duke GE (1986) "Alimentary canal: secretion and digestion, special digestive functions". In: Sturkie PD (ed.) Avian Physiology, 4th edn, pp. 289–382. New York: Springer.
    Houdry J, Hermite AL and Ferrand R (1996) Changes in the digestive tract and feeding behaviour of anurian amphibians during metamorphosis. Physiological Zoology 60: 219–251.
    book Luppa H (1977) "Histology of the digestive tract". In: Gans CE and Parsons TS (eds) Biology of the Reptilia, vol. 6, pp. 225–314. New York: Academic Press.
    book Parsons TS and Cameron JE (1977) "Internal relief of the digestive tract". In: Gans CE and Parsons TS (eds) Biology of the Reptilia, vol. 6, pp. 159–224. New York: Academic Press.
    book Reeder WG (1964) "The digestive system". In: Moore JA (ed.) Physiology of the Amphibia, vol. 1, pp. 99–149. New York: Academic Press.
    book Stevens CE (1977) "Comparative physiology of the digestive system". In: Swenson MJ (ed.) Duke's Physiology of Domestic Animals, 9th edn, pp. 216–232. Ithaca, NY: Cornell University Press.
    book Stevens CE and Hume ID (1995) Comparative Physiology of the Vertebrate Digestive System, 2nd edn. New York: Cambridge University Press.
    Stevens CE and Hume ID (1998) Contributions of microbes in the vertebrate gastrointestinal tract to the production and conservation of nutrients. Physiological Reviews 78: 393–427.

Related Sub-Topics:

Physiological Ecology | Herbivory, Predation and Parasitism
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Article Title: Digestive System of Amphibians, Reptiles and Birds
 
How to Cite close
Stevens, C Edward(Apr 2001) Digestive System of Amphibians, Reptiles and Birds. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0001839]