Bird Blue

Bird

Birds are vertebrate animals constituting the class Aves, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. They are warm-blooded, live worldwide, and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m common ostrich. There are over 11,000 living species of birds, classified in 44 orders. More than half of the world's bird species are passerine or "perching" birds. Nearly all birds have wings whose development varies according to the life style of each species. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The only known groups without wings are the extinct moa and elephant birds. Birds are the only extant members of Dinosauria, and are a type of paravian theropods. The digestive and respiratory systems of birds are uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. The study of birds is called ornithology.

Blue

Blue is one of the three primary colours in the RGB (additive) colour model, as well as in the RYB colour model. It lies between violet and cyan on the spectrum of visible light. The term blue generally describes colours perceived by humans observing light with a dominant wavelength between approximately 450 and 495 nanometres. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering. An optical effect called the Tyndall effect explains blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective.

bird

Noun

1. An animal of the clade (traditionally class) Aves in the phylum Chordata, characterized by being warm-blooded, having feathers and wings usually capable of flight, having a beaked mouth, and laying eggs.
2. Any winged animal.

Verb

1. To observe or identify wild birds in their natural environment.
2. To catch or shoot birds; to hunt birds.

blue

Adjective

1. Of a blue hue.
2. Depressed, melancholic, sad.

Noun

1. The colour of the clear sky or the deep sea; the colour midway between green and violet in the visible spectrum and one of the primary additive colours.
2. Anything coloured blue, especially to distinguish it from similar objects differing only in colour.