Chordate Zoology - Textbook - Y. V. Tsaryk - 2013

Chapter 5. SUPERCLASS TETRAPODS (TERRESTRIAL VERTEBRATES) TETRAPODA, seu QUADRIPEDA.

ANAMNIOTS (ANAMNIA) AND AMNIOTES (AMNIOTA)

5.3. CLASS BIRDS AVES

5.3.3. Taxonomy and characteristics of representatives of the main orders of the class Aves

5.3.3.2. Superorder Typical, or Neognathate Birds Neognathae

5.3.3.2.2. Order Rheiformes

Two species of ostrich-like birds inhabiting the savannas and semi-deserts of South America. They differ from African ostriches in smaller size — their

mass is 20-25 kg. Their plumage is brown, and they have three toes on their hind limbs. Between 2 and 6 females stay with a single male, laying up to 20-30 eggs in a nest scrape dug by the male. The clutch is incubated exclusively by the male for six weeks, and he also tends to the brood. Birds reach sexual maturity at the age of 2-3 years. A typical representative of the order is the greater rhea Rhea americana (Fig. 5.45, 3).