Vertebrate Zoology - V. M. Konstantinov 2011

Chordates
Terrestrial, or Tetrapod, Vertebrates — Vertebrates with Embryonic Membranes
Class Birds — Subclass Fan-tailed Birds, or True Birds — Superorder Neognathae, or Typical Birds — Order Coraciiformes

Rollers (Coraciiformes) are a vast (around 270 species) and ecologically and structurally diverse group of birds (body mass ranging from 5–7 g to 4.5 kg) united into a single order based on certain shared Anatomical Features (such as The Structure of the palate and neck). These birds feature bright plumage that is similar in both males and females. They nest in burrows and tree cavities and are primarily distributed across tropical regions. The order is divided into several suborders, indicating the distinct evolutionary independence of the groups comprising it.

The suborder Coracii (rollers proper) externally resembles corvids, such as jackdaws. It mainly includes tropical species. In Russia, the European roller (Coracias garrulus) is found; it is about the size of a jackdaw and boasts a striking blue-turquoise coloration. It nests in tree cavities and earth burrows in the southern PARTS OF THE country.

The suborder Alcedines (kingfishers) comprises small forest and riparian birds characterized by an elongated, conical bill and exceptionally vibrant plumage. They inhabit predominantly tropical regions. In Russia, the common kingfisher (Alcedo atthis) occurs along riverbanks. These birds sit motionlessly on branches hanging over the Water, and upon spotting a fish, plunge headlong into the water to catch it. They nest in burrows.

The suborder Meropes (bee-eaters) consists of brightly colored, slender birds with long bills and pointed wings. They feed on flying insects caught on the wing, much like swallows. In the southern Regions of the European part of Russia, the European bee-eater (Merops apiaster) is widespread, occasionally causing local agricultural damage by preying on honeybees. They nest in burrows.

The suborder Upupae (hoopoes) includes small arboreal and terrestrial birds with long, sickle-shaped downcurved bills and striking coloration (see Fig. 148). A specialized uropygial (preen) gland secretes a foul-smelling dark fluid that the female squirts as a defense against predators. They nest in tree cavities. The Eurasian hoopoe (Upupa epops) is common in the central and southern regions of Russia.

The suborder Bucerotes (hornbills) comprises large tropical forest birds of Asia and Africa with brilliant plumage and enormous bills. They are arboreal and feed primarily on fruit. They nest in natural tree cavities, sealing the entrance with mud so that only a small slit remains, through which the male feeds the incubating female. The female remains walled up inside the cavity for about three weeks. Once the chicks grow larger, the birds break open the seal, and the brood emerges from the nest.