Anatomy and Physiology
Ostrich
The ostrich is largely considered a monogastric herbivore, even though it consumes some insects(1). Their digestive efficiency is comparable to that of herbivorous mammals because they can digest and degrade about 38% cellulose and 66% hemicellulose of their consumed meals(4,5). However, ostriches are not able to chew due to lack of teeth nor ruminate(6). As demonstrated by the video below, ostriches peck at the ground, grab food and stores it in their gullet (throat)(6). Once the bolus of food is large enough, they swallow the food(6).
The ostrich is largely considered a monogastric herbivore, even though it consumes some insects(1). Their digestive efficiency is comparable to that of herbivorous mammals because they can digest and degrade about 38% cellulose and 66% hemicellulose of their consumed meals(4,5). However, ostriches are not able to chew due to lack of teeth nor ruminate(6). As demonstrated by the video below, ostriches peck at the ground, grab food and stores it in their gullet (throat)(6). Once the bolus of food is large enough, they swallow the food(6).
When food is swallowed, it enters the proventriculus, which is a thin-walled glandular stomach(6). Next, the food enters the ventriculus(6). This compartment contains stones of various sizes which are purposely ingested by the ostrich to grind up food into a paste(6). This bolus of food enters the small intestine which measures to be about 9 meters long, and goes along to the paired caeca and colon which measure to be about 1 meter and 10-16 meters respectively(6).
Flamingo
Flamingos are omnivorous animals. They drag their mandibles through the mud and water, pumping and sucking portions of water and mud(6,7). Once the upper mandible closes, mud and water are forced out, and prey are left inside the mouth(6,7). This is how the flamingo filter feeds(6,7). The digestive tract of the flamingo is similar to that of the ostrich, but less complex and shorter. However, an appropriate digestive diagram for the flamingo could not be found.
Flamingo
Flamingos are omnivorous animals. They drag their mandibles through the mud and water, pumping and sucking portions of water and mud(6,7). Once the upper mandible closes, mud and water are forced out, and prey are left inside the mouth(6,7). This is how the flamingo filter feeds(6,7). The digestive tract of the flamingo is similar to that of the ostrich, but less complex and shorter. However, an appropriate digestive diagram for the flamingo could not be found.
"Caribbean Flamingo Eating Up Close " Youtube. Youtube. 28 May 2013. Web. 22 February 2015. [https://www.youtube.com/watch?v=3YkP60bMTDs]
References:
- Milton SJ, Richard W, Dean J, Siegfried WR. Food Selection by Ostrich in Southern Africa. J Wildlife Manage 1994; 58:2 234-248.
- Johnson A, Cézilly F. The greater flamingo. London: T&A D Poyser; 2007.
- Stevens CE, Hume ID. Comparative Physiology of the Vertebrate Digestive System. New York: Cambridge University Press; 1995.
- Withers PC. Energy, water, and solute balance of the ostrich struthio camelus. Physiol Zool 1983; 56:4 568-579.
- Williams JB, Siegfried WR, Milton SJ, Adams NJ, Dean WRJ, du Plessis MA, Jackson S. Field Metabolism, Water Requirements, and Foraging Behavior of Wild Ostriches in the Namib. Ecology 1993; 74:2 390-404.
- Deeming DC, editor. The ostrich biology, production and health. New York: CABI Publishing; 1999.
- Zweers G, de Jong F, Berkhoudt H, Vanden Berge JC. Filter Feeding in Flamingos (Phoenicopterus ruber). Condor 1995; 97:2 297-324.