Food and Nutritional Values
The Common Ostrich
An ostrich does not need much water intake because they receive water from the succulent vegetation they consume(1). However, a dehydrated ostrich will seek water and refuse any other food(3). They can drink up to 10 litres of water in one go(3).
Ostriches avoid foods that contains high concentrations of sodium (greater than 9%) and plants with low concentrations of calcium and oxalate(1). They also avoided foods that were toxic to sheep, cattle and horses(1).
During dry seasons in arid regions, ostriches would gather around watering holes and forage on green plants found near these areas(1). Otherwise, if forbs and green plants are not at their disposal, they browse leaves from shrubs, flowers and fruit(1). Ostriches may consume grasshoppers and locusts as well, but they are not dependent on these food items(4).
An ostrich does not need much water intake because they receive water from the succulent vegetation they consume(1). However, a dehydrated ostrich will seek water and refuse any other food(3). They can drink up to 10 litres of water in one go(3).
Ostriches avoid foods that contains high concentrations of sodium (greater than 9%) and plants with low concentrations of calcium and oxalate(1). They also avoided foods that were toxic to sheep, cattle and horses(1).
During dry seasons in arid regions, ostriches would gather around watering holes and forage on green plants found near these areas(1). Otherwise, if forbs and green plants are not at their disposal, they browse leaves from shrubs, flowers and fruit(1). Ostriches may consume grasshoppers and locusts as well, but they are not dependent on these food items(4).
The Greater Flamingo
Flamingos obtain food from the water column or mud, in which they have to stir up in order to loosen it and retrieve their prey(2). They are able to choose the size of the prey that they swallow, but not the type(2). Their upper mandible is like a hinged lid which becomes the "lower mandible" when they dip their heads in the water to feed(2). The edges are lined with hook-like filters which are coarse towards the tip and gradually become finer(2). This prevents the bill from completely closing(2). Flamingos can use their bill as forceps to pick up larger prey(2). Inside their bill, there is lamellae which filters out mud and unwanted particles(2). Flamingos forage in flocks, day and night, depending on their location and season(2). They are able to drink as they eat, but sometimes they also make short distance trips to a body of fresh water where they drink, bathe and preen(2). Flamingos sometimes eat seeds of aquatic plants and rice as well(2). |
The diagram to the right shows different methods of feeding. (A) depicts walking and filtering/grubbing; here they filter out shrimp or even larger food particles while walking forward with their heads immersed in the water(2). (B) up-ending; when water is too deep, they need to "up-end" like a swan and paddle their feet to remain in a verticle position while searching for food at the bottom of the water column(2). (C) stamping; stamping and turning in a circle in the mud creates saucer-like depressions(2). This method is used to search for small invertebrates or larvae buried in the mud(2). (D) stamping "marking time"; stamping in place, and sometimes moving backwards as it finds small invertebrates coming up from the mud(2). (E) skimming; when food particles are at the surface of the water, particularly brine shrimp cysts, the flamingo will dip only a small portion of its upper mandible into the water and, with a side to side scything motion, collect the food particles(2). (F) walking "leaving tracks"; the flamingo is slowly walking forwards, head immersed in the water and bill in the mud collecting food particles as it moves its head from side to side(2).
Mussels spawn between April and June, with declining flesh weight from October to March(5).
Mussels spawn between April and June, with declining flesh weight from October to March(5).
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.
- Withers PC. Energy, water, and solute balance of the ostrich struthio camelus. Physiol Zool 1983; 56:4 568-579.
- Deeming DC, editor. The ostrich biology, production and health. New York: CABI Publishing; 1999.
- Dare PJ, Edwards DB. Seasonal changes in flesh weight and biochemical composition of mussels (Mytilus edulis L.) in the Conwy Estuary, North Wales. J Exp Mar Biol Ecol 1975; 18 89-97.
- Caudell JN, Conover MR. Energy content and digestibility of brine shrimp (Artemia franciscana) and other prey items of eared grebes (Podiceps nigricollis) on the Great Salt Lake, Utah. Biol Conserv 2006; 130 251-254.