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Author:
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Category : Painters, New Zealand
Languages : en
Pages :
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Author:
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ISBN:
Category : Painters, New Zealand
Languages : en
Pages :
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Author: Vincent Bronson
Publisher:
ISBN:
Category :
Languages : en
Pages : 98
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Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized 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. Birds live worldwide and range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have wings whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which evolved from 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 digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming.Birds are a group of feathered theropod dinosaurs, and constitute the only living dinosaurs. Likewise, birds are considered reptiles in the modern cladistic sense of the term, and their closest living relatives are the crocodilians. Birds are descendants of the primitive avialans (whose members include Archaeopteryx) which first appeared about 160 million years ago (mya) in China. According to DNA evidence, modern birds (Neornithes) evolved in the Middle to Late Cretaceous, and diversified dramatically around the time of the Cretaceous-Paleogene extinction event 66 mya, which killed off the pterosaurs and all non-avian dinosaurs.Many social species pass on knowledge across generations, which is considered a form of culture. 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. The vast majority of bird species are socially (but not necessarily sexually) monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life. Other species have breeding systems that are polygynous (one male with many females) or, rarely, polyandrous (one female with many males). Birds produce offspring by laying eggs which are fertilised through sexual reproduction. They are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching.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. Songbirds, parrots, and other species are popular as pets. Guano (bird excrement) is harvested for use as a fertiliser. Birds figure throughout human culture. About 120 to 130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry.The first classification of birds was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae. Carl Linnaeus modified that work in 1758 to devise the taxonomic classification system currently in use. Birds are categorised as the biological class Aves in Linnaean taxonomy. Phylogenetic taxonomy places Aves in the dinosaur clade Theropoda.
Author: Primitive Bird Group
Publisher:
ISBN:
Category : Painting, New Zealand --new Zealand --christchurch --21st Century --exhibitions
Languages : en
Pages : 0
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Author: Hilde Widerberg
Publisher: Createspace Independent Publishing Platform
ISBN: 9781496019981
Category : Nature
Languages : en
Pages : 26
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Based on fossil and biological evidence, most scientists accept that birds are a specialized subgroup of theropod dinosaurs. More specifically, they are members of Maniraptora, a group of theropods which includes dromaeosaurs and oviraptorids, among others. As scientists have discovered more nonavian theropods closely related to birds, the previously clear distinction between nonbirds and birds has become blurred. Recent discoveries in the Liaoning Province of northeast China, which demonstrate many small theropod dinosaurs had feathers, contribute to this ambiguity. The consensus view in contemporary paleontology is that the birds, or avialans, are the closest relatives of the deinonychosaurs, which include dromaeosaurids and troodontids. Together, these form a group called Paraves. Some basal members of this group, such as Microraptor, have features which may have enabled them to glide or fly. The most basal deinonychosaurs were very small. This evidence raises the possibility that the ancestor of all paravians may have been arboreal, have been able to glide, or both. Unlike Archaeopteryx and the non-avian feathered dinosaurs, who primarily ate meat, recent studies suggest that the first birds were herbivores. The Late Jurassic Archaeopteryx is well known as one of the first transitional fossils to be found, and it provided support for the theory of evolution in the late 19th century. Archaeopteryx was the first fossil to display both clearly traditional reptilian characteristics: teeth, clawed fingers, and a long, lizard-like tail, as well as wings with flight feathers identical to those of modern birds. It is not considered a direct ancestor of modern birds, though it is possibly closely related to the real ancestor. Early disagreements on the origins of birds included whether birds evolved from dinosaurs or more primitive archosaurs. Within the dinosaur camp, there were disagreements as to whether ornithischian or theropod dinosaurs were the more likely ancestors. Although ornithischian (bird-hipped) dinosaurs share the hip structure of modern birds, birds are thought to have originated from the saurischian (lizard-hipped) dinosaurs, and therefore evolved their hip structure independently. In fact, a bird-like hip structure evolved a third time among a peculiar group of theropods known as the Therizinosauridae. A small minority of researchers, oppose the majority view, contending that birds are not dinosaurs, but evolved from early reptiles like Longisquama. The earliest known bird (avialan) fossils currently known hail from the Tiaojishan Formation of China, which has been dated to the late Jurassic period (Oxfordian stage), about 160 million years ago. The avialan species from this time period include Anchiornis huxleyi, Xiaotingia zhengi, and Aurornis xui. The well-known early avialan, Archaeopteryx, dates from slightly later Jurassic rocks (about 155 million years old) from Germany. Many of these early avialans shared unusual anatomical features that may be ancestral to modern birds, but were later lost during bird evolution. These features include enlarged claws on the second toe which may have been held clear of the ground in life, and long feathers or "hind wings" covering the hind limbs and feet, which may have been used in aerial maneuvering. Avialans diversified into a wide variety of forms during the Cretaceous Period. Many groups retained primitive characteristics, such as clawed wings and teeth, though the latter were lost independently in a number of bird groups, including modern birds (Neornithes). While the earliest forms, such as Archaeopteryx and Jeholornis, retained the long bony tails of their ancestors, the tails of more advanced birds were shortened with the advent of the pygostyle bone in the clade Pygostylia. In the late Cretaceous, around 95 million years ago, the ancestor of all modern birds also evolved better olfactory senses.
Author: Gerhard Heilmann
Publisher:
ISBN:
Category : Birds
Languages : en
Pages : 222
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Book Description
Author: Jason A. Mobley
Publisher: Marshall Cavendish
ISBN: 9780761477754
Category : Nature
Languages : en
Pages : 928
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Book Description
Birds of all imaginable sizes, shapes, colors, and patterns are nearly everywhere we might care to look, expressing a bewildering array of behaviors and strategies for successful living among all manner of challenges to survival.
Author: Donald Farner
Publisher: Elsevier
ISBN: 0323157998
Category : Nature
Languages : en
Pages : 281
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Book Description
Avian Biology,Volume VIII assesses selected aspects of avian biology. It is generally the conceptual descendant of Marshall's earlier treatise,"Biology and Comparative Physiology of Birds, but is more than simply a revision of it. This volume consists of two relatively lengthy, diverse chapters that focus on adaptive significance of coloniality in birds and fossil records of birds. In particular, this volume looks into group phenomena related to central place systems, that is, systems in which one or more individuals move to and from a centrally located place in the course of daily activities. It also addresses selective factors that have been suggested to explain why individuals should form colonies rather than disperse within the available foraging space. This book will be useful as a reference material for advanced students and instructors in this field of interest.
Author: Pete Dunne
Publisher: Stackpole Books
ISBN: 0811731960
Category : Nature
Languages : en
Pages : 194
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Book Description
A straightforward approach getting good, then better, at identifying birds in the field-and having fun doing it.
Author: Sidney Dillon Ripley
Publisher: David R. Godine Publisher
ISBN: 9780919880078
Category : Rails (Birds)
Languages : en
Pages : 444
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Book Description
Author: Rodney Rothman
Publisher: Simon and Schuster
ISBN: 1416537031
Category : Biography & Autobiography
Languages : en
Pages : 316
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Book Description
Everyone says they would like to retire early, but Rodney Rothman actually did it—forty years early. Burnt out, he decides at the age of twenty-eight to get an early start on his golden years. He travels to Boca Raton, Florida, where he moves in with an elderly piano teacher at Century Village, a retirement community that is home to thousands of senior citizens. Early Bird is an irreverent, hilarious, and ultimately warmhearted account of Rodney's journey deep into the heart of retirement. Rodney struggles for acceptance from the senior citizens he shares a swimming pool with and battles with cranky octogenarians who want him off their turf. Before long he observes, “I don't think Tuesdays with Morrie would have been quite so uplifting if that guy had to spend more than one day a week with Morrie.” In the spirit of retirement, Rodney fashions a busy schedule of suntanning, shuffleboard, and gambling cruises. As the months pass, his neighbors seem to forget that he is fifty years younger than they are. He finds himself the potential romantic interest of an aging femme fatale. He joins a senior softball club and is disturbed to learn that he is the worst player on the team. Early Bird is a funny, insightful, and moving look at what happens to us when we retire, viewed from a remarkably premature perspective. Any reader who plans on becoming an old person will enjoy joining Rodney on his strange journey, as he reconsiders his notions of romance, family, friendship, and ultimately, whether he's ever going back to work.
