Vertebrate Zoology - V. M. Konstantinov 2011

Chordates
Terrestrial, or Tetrapod, Vertebrates — Amniotes
Class Aves — Subclass Neornithes — Superorder Neognathae — Order Piciformes

The order Piciformes comprises 358 species divided into two suborders: Galbulae (puffbirds and jacamars) and Pici (woodpeckers and allies).

Highly specialized arboreal birds of small to medium size (body mass ranging from 6 to 300 g), which nest and forage in trees, feeding on seeds, fruits, or insects inhabiting bark and wood. Food is obtained using a bill of variable shape, which is always well-developed and entirely cornified. Some species, such as the barbets (Capitonidae) of South Asia and Africa, catch insects much like Old World flycatchers by waiting for them while perched on branches. Species from Central and South America, tropical Asia, and Africa feed more frequently on fruits and berries. They are exceptionally agile climbers. Their claws are curved and the body is flexible because the dorsal vertebrae are not fused. Distributed primarily in the tropics. They nest in natural cavities or excavated hollows and burrows. A clutch of 2 to 10 eggs is incubated in turn by both partners. The chicks are altricial.

Toucanet-like birds, or toucans (Rhamphastidae), are inhabitants of the tropical forests of South and Central America. These are brightly colored birds with a massive bill bearing serrated edges (see Fig. 148). They feed on fruits, and less frequently on birds and their eggs. They nest in tree cavities.

True woodpeckers (Pici) represent a very numerous group of climbing arboreal birds with a chisel-like bill; their legs are short with curved claws, and the outer toe can reverse backward. The tail feathers feature stiff, pointed shafts. When climbing tree trunks, woodpeckers brace themselves against their tail feathers, which serve as a prop for the bird resting on the bark. They feed on insects and their larvae, extracting them from bark and wood by destroying it with their chisel-like bill. The Tongue is exceptionally long, with barbules at the tip. The horns of the hyoid apparatus extend along the sides of the Skull, curve upward over the back of the HEAD, and continue along the crown to the forehead, sometimes even reaching the upper jaw. When the hyoid apparatus moves forward, the tongue extends from the gap in the bill to a length exceeding that of the head. In addition to insects, woodpeckers consume conifer seeds. They nest in cavities, which they often excavate themselves in trees with decayed heartwood. A clutch of 2 to 4 eggs is incubated alternately by the female and male for 11 to 18 days. The chicks are altricial and are fed by the parents for up to 5 weeks.

The fauna of Russia includes more than 10 species. The main ones are the black woodpecker, or pileated woodpecker (Dryocopus martius), the great spotted woodpecker (Dendrocopus major, see Fig. 148), the lesser spotted woodpecker (D. minor), the Eurasian three-toed woodpecker (Picoides tridactylus), and the European green woodpecker (Picus viridis).

Woodpeckers play a major positive role in forest ecosystems. Every day they destroy many hundreds of pest insects, such as bark beetles, weevils, and silkworm caterpillars. Their utility is especially high in summer when woodpeckers feed on insects. In winter, they more frequently consume conifer seeds. Plucked cones are wedged by woodpeckers into crevices carved in trees or into a fork between branches, and only then are the seeds extracted. The used cones are dropped to the ground. The sites where woodpeckers wedge the cones are called «anvils». Beneath these «anvils», large piles of used cones often accumulate, numbering several hundred pieces and occasionally exceeding a thousand. The Damage caused by woodpeckers is negligible and is far outweighed by their beneficial activities. The positive role of woodpeckers in the life of the forest is reflected in the popular adage: «The woodpecker is the doctor of the forest».

In South Africa lives the peculiar ground woodpecker (Geocolaptes olivaceus), which, unlike the vast majority of species, inhabits treeless areas along rocky mountain slopes, the banks of deep river beds, and ravines. It digs burrows up to 1 m long in riverbanks and lines its nest with Hair.

The IUCN Red List includes 11 species of woodpeckers. Due to deforestation and Human Development, by the mid-20th century the ivory-billed woodpecker (Campephilus principalis), formerly native to the USA, became extinct.