Dave Taylor's African Safari: Trophic Level II - The Herbivores - Masai Ostrich

Dave Taylor's African Safari: Trophic Level II - The Herbivores - Masai Ostrich - Page 8

Trophic Level II - The Herbivores
Masai Ostrich
Page 8

Struthio camelus massaics

Height: 250 cm (8’)

Weight: 150 kg (330 lb.)

Status: Not endangered but numbers are declining in the wild

(Author’s note: Masai is the spelling given to many species and locations found within this ecosystem. These names were given by naturalists and explorers a hundred years ago. The tribe, from whom these names are derived, spells it Maasai- with a double "a". They speak the "Maa" language. The accepted spelling of the animal’s names and locations has remained Masai, however).

Habitat: Masai ostriches are found up to 2 000 meters (6,560 feet) in altitude. They like dry, open country.

Food: Masai ostriches eat roots, leaves, flowers, fruit and seeds but will eat also locusts, small lizards and even small tortoises.

Behavior: At one time, the ancestors of the ostrich were found in Asia, Africa and Europe. Today, only this species survives but there are several local races. The blue-necked or Somalia ostrich is also found in East Africa. It is commonly seen in northern Kenya.

Ostriches do have some close cousins that share the same Order, the Struthioniformes or Ratites. These are, with one exception, large, flightless birds and include South America’s rhea, the Australian cassowary and emu and New Zealand’s kiwi, the smallest of the group. (Author’s note: Some scientists feel that each group deserves its own Order.)

These birds have all lost their ability to fly and have developed large leg muscles for running from predators.

Ostriches have two toes. The largest is clawed and is used as a weapon against enemies.

Ostriches have three stomach sections to help them digest the plant material. Lacking teeth with which to chew, they will swallow small stones to help grind their food. These small stones become rounded with wear and are called gastroliths. From time to time the ostrich will regurgitate these stones and seek new ones.

The World’s Largest Eggs

Ostriches lay the world’s largest eggs. They weigh between 775 and 1 618 grams (1.7 to 3.5 lb.). The egg shells are so thick that a lion cannot bite through them. The only predator with jaws strong enough to crack open an ostrich egg is the spotted hyena.

The Egyptian vulture has solved the problem and is able to take advantage of this source of food. It will pick up a rock with its beak and repeatedly drop it on the egg until the egg breaks.

Ostrich males will either practice monogamy and pair up with one female, or they may live in polygamous groups of one male and several hens. The most commonly seen groupings consist of one male, a dominant "main" hen and two or more subordinate "auxiliary" hens. This is called polygyny.

Hens will either have their own nest or they may lay their eggs in one large nest. They may also lay a few eggs in several communal nests. Nests with over 100 eggs have been recorded. All three nesting styles have been documented. In most cases, there may be over forty eggs to a nest but many will not hatch as the parent bird often cannot incubate them all. About two dozen eggs is a reasonable number for a bird to sit on.

The most commonly seen nesting behavior occurs when the dominant female sits on a single nest during the day and the male sits on it at night. Auxiliary hens are chased away.

In the Serengeti-Mara ecosystem, each hen lays up to 30 eggs in a communal nest. The eggs are laid one a day and are not incubated until all of the eggs have been deposited. This allows all of the eggs to hatch on the same day. Even so, there are far too many eggs for the male and the dominant female to sit on, and many perish.

The loss of an egg is not important to an ostrich. The egg costs her relatively little to produce, compared to what a songbird puts into its egg. A typical songbird’s egg weighs about one-tenth its own weight. An ostrich’s egg is only equal to one-sixtieth of its parent’s weight.

In this ecosystem, the ostriches breed from August to December. The young hatch from December through January. Large numbers of chicks will attach themselves to the adults and it is not uncommon to see 60 in a group.

Predators: Young ostriches follow their parents and are well guarded. Even so, predators find ostrich meat much to their liking. Lions will prey on adults and juvenile ostriches are fair game for a host of eagles, jackals and other predators. An ostrich often sees an enemy approaching, thanks to its long neck and excellent eyesight. The best defense may be a quick exit. Ostriches can run at 70 kilometers per hour (43 mph). They can also jump over meter-high (yard) obstacles like fallen logs.

Ostriches never hide their heads in the sand.

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