A cage is an enclosure often made of mesh , bars, or wires , used to confine, contain or protect something or someone. A cage can serve many purposes, including keeping an animal or person in captivity , capturing an animal or person, and displaying an animal at a zoo .
41-525: Since a cage is usually intended to hold living beings, at least some part of its structure must be such as to allow for the entry of light and air. Thus some cages may be made with bars spaced closely together for the intended captive to slip between them, or with windows covered by a mesh of some sort. Cages often used to confine animals, and some are specially designed to fit a certain species of animal. One or more birds , rodents , reptiles , and even larger animals of certain breeds are sometimes confined in
82-774: A better sense of smell. A third stage of bird evolution starting with Ornithothoraces (the "bird-chested" avialans) can be associated with the refining of aerodynamics and flight capabilities, and the loss or co-ossification of several skeletal features. Particularly significant are the development of an enlarged, keeled sternum and the alula , and the loss of grasping hands. † Anchiornis † Archaeopteryx † Xiaotingia † Rahonavis † Jeholornis † Jixiangornis † Balaur † Zhongjianornis † Sapeornis † Confuciusornithiformes † Protopteryx † Pengornis Ornithothoraces † Enantiornithes Bee hummingbird The bee hummingbird , zunzuncito or Helena hummingbird ( Mellisuga helenae )
123-457: A cage as pets . Animal cages have been a part of human culture since ancient times. For example, an Ancient Greek vase dated to 490 B.C. depicts a boy holding a possibly domesticated rabbit on his lap, with a cage with an open door in the background. The biblical Book of Jeremiah refers to a tribe being like "cages full of birds", and the Book of Ezekiel describes the capture of a lion in which
164-493: A cage-like structure, and "conjures up the image of two combatants trapped in a cage, trading vicious blows as the audience bays for blood". In Australia , a ban on the use of "cage-like enclosures" at such events was lifted in 2014. Steel cages are also one of the oldest form of enclosures used in professional wrestling . The first "steel cage match" of any kind took place on June 25, 1937 in Atlanta, Georgia . This match took place in
205-473: A definition similar to "all theropods closer to birds than to Deinonychus ", with Troodon being sometimes added as a second external specifier in case it is closer to birds than to Deinonychus . Avialae is also occasionally defined as an apomorphy-based clade (that is, one based on physical characteristics). Jacques Gauthier , who named Avialae in 1986, re-defined it in 2001 as all dinosaurs that possessed feathered wings used in flapping flight , and
246-442: A group called Paraves . Some basal members of Deinonychosauria, 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-avialan feathered dinosaurs, who primarily ate meat, studies suggest that
287-477: A ring surrounded by chicken wire , in order to keep the athletes inside, and prevent any potential interference. Bird Birds are a group of warm-blooded vertebrates constituting the class Aves ( Latin: [ˈaveːs] ), 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 . Birds live worldwide and range in size from
328-406: A sister group, the order Crocodilia , contain the only living representatives of the reptile clade Archosauria . During the late 1990s, Aves was most commonly defined phylogenetically as all descendants of the most recent common ancestor of modern birds and Archaeopteryx lithographica . However, an earlier definition proposed by Jacques Gauthier gained wide currency in the 21st century, and
369-717: A time, sometimes for years, and 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)
410-645: A trapping tool. This is a common and illegal purpose of the cage, as poaching is illegal itself. These type of cages are used to trap an animal, or hold them for a certain period of time. U.S. President Theodore Roosevelt used a cage himself to capture a bear , as the cage serves a purpose for capturing large animals. In history, prisoners were sometimes kept in a cage. During the Vietnam War they were referred to as "tiger cages". Captives would sometimes be chained up inside into uncomfortable positions to intensify suffering. In medieval England, King Edward punished Robert
451-469: Is March–June, with the female laying one or two eggs. Using strands of cobwebs , bark , and lichen , female bee hummingbirds build a cup-shaped nest about 2.5 cm (1 in) in diameter and 3–5 m (9.8–16.4 ft) off the ground. The nest is lined with a layer of soft plant wool. Branches in mature, leafy jucaro ( Terminalia buceras ) and juvenile ocuje ( Calophyllum antillanum ) trees are commonly used for nest building. After completion of
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#1732844763801492-624: Is a species of hummingbird , native to the island of Cuba in the Caribbean . It is the smallest known bird . The bee hummingbird feeds on nectar of flowers and bugs found in Cuba. The bee hummingbird is the smallest living bird . Females weigh 2.6 g (0.092 oz) and are 6.1 cm ( 2 + 3 ⁄ 8 in) long, and are slightly larger than males, which have an average weight of 1.95 g (0.069 oz) and length of 5.5 cm ( 2 + 1 ⁄ 8 in). Like all hummingbirds, it
533-460: Is a swift, strong flier. The male has a green pileum and bright red throat, iridescent gorget with elongated lateral plumes , bluish upper parts, and the rest of the underparts mostly greyish white. Compared to other small hummingbirds, which often have a slender appearance, the bee hummingbird looks rounded and plump. Female bee hummingbirds are bluish green with a pale gray underside. The tips of their tail feathers have white spots. During
574-712: Is fragmented; it is found in Cuba's mogote areas in Pinar del Río Province and more commonly in Zapata Swamp ( Matanzas Province ) and in eastern Cuba, with reference localities in Alexander Humboldt National Park and Baitiquirí Ecological Reserve ( Guantánamo Province ) and Gibara and Sierra Cristal ( Holguín Province ). Bee hummingbirds reach sexual maturity at one year of age. Male bee hummingbirds court females with sound from tail-feathers, which flutter during display dives. The bee hummingbird's breeding season
615-429: 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
656-503: Is not considered a direct ancestor of birds, though it is possibly closely related to the true ancestor. Over 40% of key traits found in modern birds evolved during the 60 million year transition from the earliest bird-line archosaurs to the first maniraptoromorphs , i.e. the first dinosaurs closer to living birds than to Tyrannosaurus rex . The loss of osteoderms otherwise common in archosaurs and acquisition of primitive feathers might have occurred early during this phase. After
697-516: Is synonymous to Avifilopluma. † Scansoriopterygidae † Eosinopteryx † Jinfengopteryx † Aurornis † Dromaeosauridae † Troodontidae Avialae Based on fossil and biological evidence, most scientists accept that birds are a specialised subgroup of theropod dinosaurs and, more specifically, members of Maniraptora , a group of theropods which includes dromaeosaurids and oviraptorosaurs , among others. As scientists have discovered more theropods closely related to birds,
738-530: Is used by many scientists including adherents to the PhyloCode . Gauthier defined Aves to include only the crown group of the set of modern birds. This was done by excluding most groups known only from fossils , and assigning them, instead, to the broader group Avialae, on the principle that a clade based on extant species should be limited to those extant species and their closest extinct relatives. Gauthier and de Queiroz identified four different definitions for
779-660: 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 probable 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
820-561: The only known 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 during the Late Jurassic . According to recent estimates, modern birds ( Neornithes ) evolved in the Late Cretaceous and diversified dramatically around
861-433: The 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich . There are over 11,000 living species and they are split into 44 orders . More than half 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 are modified forelimbs , gave birds
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#1732844763801902-513: The Bruce by having two of his female supporters encaged in public. Cages are used in various forms of entertainment to create excitement from the sense that the entertainers are trapped in the cage. For example, cage dancing "refers to a scantily-clad feminine dancer, perhaps wearing a mini-skirt or hot- pants, and (supposedly) trapped inside of a hanging bird cage". Cage fighting involves two combatants, usually engaging in mixed martial arts , inside
943-480: 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. The study of birds is called ornithology . Birds are feathered theropod dinosaurs and constitute
984-411: The air to feed on flowers. The bee hummingbird lives up to seven years in the wild, and 10 years in captivity. The bee hummingbird has also been described as "the smallest dinosaur ". This characterization is based upon the recognition that birds are, in fact, a living form of theropod dinosaurs (or, strictly speaking, avian dinosaurs ), and no smaller bird or non-avian dinosaur has been found in
1025-428: The appearance of Maniraptoromorpha, the next 40 million years marked a continuous reduction of body size and the accumulation of neotenic (juvenile-like) characteristics. Hypercarnivory became increasingly less common while braincases enlarged and forelimbs became longer. The integument evolved into complex, pennaceous feathers . The oldest known paravian (and probably the earliest avialan) fossils come from
1066-593: The bee hummingbird is the vervain hummingbird ( Mellisuga minima) , the only other member of its genus. The habitats of the vervain hummingbird are in Cuba's neighboring islands, Hispaniola and Jamaica . The bee hummingbird is endemic to the entire Cuban archipelago , including the main island of Cuba and the Isla de la Juventud in the West Indies . In these regions bee hummingbirds generally live in areas of thick growth that contain lianas and epiphytes. Its population
1107-509: The birds that descended from them. Despite being currently one of the most widely used, the crown-group definition of Aves has been criticised by some researchers. Lee and Spencer (1997) argued that, contrary to what Gauthier defended, this definition would not increase the stability of the clade and the exact content of Aves will always be uncertain because any defined clade (either crown or not) will have few synapomorphies distinguishing it from its closest relatives. Their alternative definition
1148-528: The captors "pulled him into a cage and brought him to the king of Babylon". The different laws governing the keeping of animals in captivity generally provide for the size of cages or minimum equipment, depending on the species, whether for transport or for breeding. Swiss legislation, for example, defines minimum absolute internal dimensions for pet cages, but the Swiss Animal Protection organization (PSA) states that even if these dimensions comply with
1189-665: The earliest members of Aves, is removed from this group, becoming a non-avian dinosaur instead. These proposals have been adopted by many researchers in the field of palaeontology and bird evolution , though the exact definitions applied have been inconsistent. Avialae, initially proposed to replace the traditional fossil content of Aves, is often used synonymously with the vernacular term "bird" by these researchers. † Coelurus † Ornitholestes † Ornithomimosauria † Alvarezsauridae † Oviraptorosauria Paraves Most researchers define Avialae as branch-based clade, though definitions vary. Many authors have used
1230-451: The first avialans were omnivores . 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 similar to those of modern birds. It
1271-419: The fossil record. The call is described as "high pitched, jumbled twitter". Within their territory a male will often sing atop the highest tree. The bee hummingbird has been reported to visit ten plant species, nine of them native to Cuba. They occasionally eat insects and spiders. In a typical day, bee hummingbirds will consume up to half their body weight in food. The closest evolutionary relative of
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1312-473: The law, they are far from being in line with the needs of species. It is therefore necessary in practice to provide a much higher vital space to ensure the well-being of the occupants. Animal protection associations have often argued for improving transport conditions in cages and for bans on battery cages, especially for egg-laying hens. The European legislation is constantly changing, but consumer behavior also influences breeding conditions. Cages also serve as
1353-460: The mating season, males have a reddish to pink head, chin, and throat. The female lays only two eggs at a time, each about the size of a coffee bean . The bee hummingbird's feathers have iridescent colors, which is not always noticeable, but depends on the viewing angle. The bird's slender, pointed bill is adapted for probing deep into flowers . The bee hummingbird feeds mainly on nectar , by moving its tongue rapidly in and out of its mouth. In
1394-402: The nest, the eggs are incubated for 21 days by only the female, followed by 2 days of hatching, and 18 days of care by the mother. During days of care the mother will hunt for small insects while chicks are left alone in the nest. Over the final 4–5 days of care , juvenile bee hummingbirds practice their flight capabilities. The nests are used only once. The bee hummingbird's interaction with
1435-402: The outermost half) can be seen in the evolution of maniraptoromorphs, and this process culminated in the appearance of the pygostyle , an ossification of fused tail vertebrae. In the late Cretaceous, about 100 million years ago, the ancestors of all modern birds evolved a more open pelvis, allowing them to lay larger eggs compared to body size. Around 95 million years ago, they evolved
1476-528: The previously clear distinction between non-birds and birds has become blurred. By the 2000s, discoveries in the Liaoning Province of northeast China, which demonstrated many small theropod feathered dinosaurs , contributed to this ambiguity. The consensus view in contemporary palaeontology is that the flying theropods, or avialans , are the closest relatives of the deinonychosaurs , which include dromaeosaurids and troodontids . Together, these form
1517-433: The process of feeding, the bird picks up pollen on its bill and head. When it flies from flower to flower, it transfers the pollen. In this way, it plays an important role in plant reproduction . In one day, the bee hummingbird may visit 1,500 flowers. It is a diurnal bird that can fly at 40–48 km/h (22–26 kn; 11–13 m/s), and it beats its wings 80–200 times per second, which allows it to remain stationary in
1558-452: The same biological name "Aves", which is a problem. The authors proposed to reserve the term Aves only for the crown group consisting of the last common ancestor of all living birds and all of its descendants, which corresponds to meaning number 4 below. They assigned other names to the other groups. Lizards & snakes Turtles Crocodiles Birds Under the fourth definition Archaeopteryx , traditionally considered one of
1599-545: 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 avialan groups, including modern birds (Aves). Increasingly stiff tails (especially
1640-600: The time of the Cretaceous–Paleogene extinction event 66 million years ago, which killed off the pterosaurs and all non- ornithuran dinosaurs. Many social species preserve knowledge across generations ( culture ). Birds are social, communicating with visual signals, calls, and songs , and participating in such behaviour 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
1681-461: 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 clade Theropoda as an infraclass or a subclass, more recently a subclass. Aves and