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

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

ANAMNIANS (ANAMNIA) AND AMNIOTES (AMNIOTA)

5.3. CLASS BIRDS AVES

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

5.3.3.2. Superorder Typical, or Neognathous Birds Neognathae

5.3.3.2.6. Order Loons Gaviiformes

The order encompasses five species of waterbirds distributed across the temperate and northern latitudes of the Northern Hemisphere. One of these species is the Pacific loon Gavia pacifica (Fig. 5.45, 7). The body and neck of these birds are elongated, and the narrow HEAD bears a straight, slender bill. The legs are set far back, with the three forward-facing toes connected by a web. They are exceptional swimmers and divers, are virtually unable to walk on land, and possess a fast, powerful flight. They feed on fish and aquatic invertebrates, diving to depths of up to 25 m to catch prey. The female lays two eggs in a primitive nest near the Water, and both parents share incubation. The chicks hatch covered in down and are capable of swimming and diving expertly right away. The parents feed the chicks for a month and a half until they are able to fly.