Vertebrate Zoology - V. M. Konstantinov 2011

Chordates
Terrestrial, or Four-Legged, Vertebrates — Amniotes
Class Birds — Subclass Fan-tailed Birds, or Modern Birds — Superorder Paleognathae, or Ratites — Order Tinamiformes

The order comprises about 47 medium-sized species (body weight ranging from 200 g to 1.5 kg) that are predominantly nocturnal. The body is robust and compact. The bill is long and slightly curved downwards. They possess a protective brownish-grey coloration; males are smaller than females and paler in color. The plumage is unique: the tips of the barbules fuse to form stiff vanes. The apteria are narrow, and down is located exclusively on the pterylae. The wings are short and wide. The rectrices are soft, completely hidden by the covert feathers of the tail and lower back. They are widely distributed in forests, shrublands, and in the lowland steppe and mountainous regions of Central and South America, ranging from Mexico to Patagonia. Some species are monogamous, with populations exhibiting an approximately equal sex ratio. Polyandry is characteristic of certain species, in which the number of males in the population exceeds the number of females. The breeding season in such species is prolonged. Females display and court males; depending on the species, they lay from one to 6–12 eggs in a single shared primitive nest, and then move on to the nesting territory of another male. The males incubate the clutch for 16–20 days and tend to the chicks. Generally omnivorous, they feed on fruits, seeds, insects, and worms. In the Americas, tinamous are considered game birds.