![]() Main article: Evolution of birds Archaeopteryx is often considered the oldest known true bird. Recreational birdwatching is an important part of the ecotourism industry. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. About 120 to 130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Guano (bird excrement) is harvested for use as a fertiliser. Songbirds, parrots, and other species are popular as pets. Many species of birds are economically important as food for human consumption and raw material in manufacturing, with domesticated and undomesticated birds being important sources of eggs, meat, and feathers. Most birds have an extended period of parental care after hatching. They are usually laid in a nest and incubated by the parents. Birds produce offspring by laying eggs which are fertilised through sexual reproduction. Other species have breeding systems that are polygynous (one male with many females) or, rarely, polyandrous (one female with many males). The vast majority of bird species are socially (but not necessarily sexually) monogamous, usually for one breeding season at a time, sometimes for years, and rarely for life. Birds are social, communicating with visual signals, calls, and songs, and participating in such behaviours as cooperative breeding and hunting, flocking, and mobbing of predators. Many social species pass on knowledge across generations, which is considered a form of culture. According to recent estimates, modern birds ( Neornithes) evolved in the Late Cretaceous and diversified dramatically around the time of the Cretaceous–Paleogene extinction event 66 million years ago, which killed off the pterosaurs and all non-avian dinosaurs. Birds are descendants of the primitive avialans (whose members include Archaeopteryx) which first appeared during the Late Jurassic. Likewise, birds are considered reptiles in the modern cladistic sense of the term, and their closest living relatives are the crocodilians. The study of birds is called ornithology.īirds are feathered theropod dinosaurs and constitute the only known living dinosaurs. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. The digestive and respiratory systems of birds are also uniquely adapted for flight. 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. Birds have wings whose development varies according to species the only known groups without wings are the extinct moa and elephant birds. ![]() There are over 11,000 living species, more than half of which are passerine, or "perching" birds. Birds live worldwide and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich. I am a fine art painter based in Indiana and focus on abstracts, nature-inspired pieces, still life, and portraits.Birds are a group of warm-blooded vertebrates constituting the class Aves ( / ˈ eɪ v iː z/), 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. If you like this color by number, you may also like my food and drink themed color by number. You aren’t permitted to redistribute content. Terms of Use: You may print these pages as many times as you’d like for personal use. Colors given are suggested, but feel free to use your imagination and choose whichever colors you’d like! Numbers may show through when finished depending on which art materials you use. Paints, pencils, brushes, and other media not included. Color variations may occur from printer to printer. You'll need to use a color printer if you'd like to use the color guides that come on each page. Thicker paper is recommended if you’re using paint. You can print the pages on any type of paper you’d like on your home printer or at a print shop. For use with acrylic paint, watercolor, colored pencil, marker, and anything else you can find that works. Images shown are digitally colorized versions of some of the sheets included. ![]() Includes 25 unique coloring pages based off paintings by award-winning artist, Lori Rivera - 5 birds, 6 landscapes, and 14 florals. No physical product will be shipped to you.
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