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Loon
Loons ( North American English) or divers ( British / Irish English) are a group of aquatic birds found in much of North America and northern Eurasia. All living species of loons are members of the genus ''Gavia'', family Gaviidae and order Gaviiformes . Description Loons, which are the size of large ducks or small geese, resemble these birds in shape when swimming. Like ducks and geese, but unlike coots (which are Rallidae) and grebes ( Podicipedidae), the loon's toes are connected by webbing. The loons may be confused with the cormorants (Phalacrocoracidae), but can be distinguished from them by their distinct call. Cormorants are not-too-distant relatives of loons, and like them are heavy-set birds whose bellies, unlike those of ducks and geese, are submerged when swimming. Loons in flight resemble plump geese with seagulls' wings that are relatively small in proportion to their bulky bodies. The bird points its head slightly upwards while swimming, but less so than cormor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gavia Immer
The common loon or great northern diver (''Gavia immer'') is a large member of the loon, or diver, family of birds. Breeding adults have a plumage that includes a broad black head and neck with a greenish, purplish, or bluish sheen, blackish or blackish-grey upperparts, and pure white underparts except some black on the undertail coverts and vent. Non-breeding adults are brownish with a dark neck and head marked with dark grey-brown. Their upperparts are dark brownish-grey with an unclear pattern of squares on the shoulders, and the underparts, lower face, chin, and throat are whitish. The sexes look alike, though males are significantly heavier than females. During the breeding season, loons live on lakes and other waterways in Canada; the northern United States (including Alaska); and southern parts of Greenland and Iceland. Small numbers breed on Svalbard and sporadically elsewhere in Arctic Eurasia. Common loons winter on both coasts of the US as far south as Mexico, and on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Loon
The Pacific loon or Pacific diver (''Gavia pacifica''), is a medium-sized member of the loon, or diver, family. Taxonomy and etymology The Pacific loon, previously considered conspecific with the similar black-throated loon, was classified as a separate species in 1985. The genus name ''Gavia'' comes from the Latin for "sea mew", as used by ancient Roman naturalist Pliny the Elder. The specific epithet ''pacifica'' is Latin for the Pacific Ocean, the term meaning "peaceful". The phylogeny of this species is debated, with the black-throated loon and the Pacific loon traditionally being considered sister species, whereas a study using mitochondrial and nuclear intron DNA supported placing the black-throated loon sister to a clade consisting of the Pacific loon and the two sister species that are the common loon and the yellow-billed loon. In the former phylogeny, the split between the Pacific loon and the black-throated loon is proposed to have happened about 6.5 million years ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaviiformes
Gaviiformes is an order of aquatic birds containing the loons or divers and their closest extinct relatives. Modern gaviiformes are found in many parts of North America and northern Eurasia (Europe, Asia and debatably Africa), though prehistoric species were more widespread. Classification and evolution There are five living species, and all are placed in the genus '' Gavia''. The loons were formerly often considered to be the most ancient of the northern hemisphere bird families; this idea grew basically out of the perceived similarity of shape and (probably) habits between loons and the entirely unrelated extinct Cretaceous order Hesperornithiformes. In particular '' Enaliornis'', which was apparently an ancestral and plesiomorphic member of that order, was sometimes used to support claims of Albian (Early Cretaceous) Gaviiformes. More recently, it has become clear that the Anseriformes (waterfowl) and the Galliformes are the most ancient groups of modern birds, and these bein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird Feet And Legs
The anatomy of bird legs and feet is diverse, encompassing many accommodations to perform a wide variety of functions. Most birds are classified as digitigrade animals, meaning they walk on their toes rather than the entire foot. Some of the lower bones of the foot (the distals and most of the metatarsal) are fused to form the tarsometatarsus – a third segment of the leg, specific to birds. The upper bones of the foot ( proximals), in turn, are fused with the tibia to form the tibiotarsus, as over time the centralia disappeared. The fibula also reduced.; ; The legs are attached to a strong assembly consisting of the pelvic girdle extensively fused with the uniform spinal bone (also specific to birds) called the '' synsacrum'', built from some of the fused bones. Hindlimbs Birds are generally digitigrade animals ( toe-walkers), which affects the structure of their leg skeleton. They use only their hindlimbs to walk (bipedalism). Their forelimbs evolved to become wings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grebe
Grebes () are aquatic diving birds in the order Podicipediformes . Grebes are widely distributed freshwater birds, with some species also found in marine habitats during migration and winter. Some flightless species exist as well, most notably in stable lakes. The order contains a single family, the Podicipedidae, which includes 22 species in six extant genera. Although, superficially, they resemble other diving birds such as loons and coots, they are most closely related to flamingos, as supported by morphological, molecular and paleontological data. Many species are monogamous and are known for their courtship displays, with the pair performing synchronized dances across the water's surface. The birds build floating vegetative nests where they lay several eggs. About a third of the world's grebes are listed at various levels of conservation concerns—the biggest threats including habitat loss, the introduction of invasive predatory fish and human poaching. As such, three ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ducks
Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form taxon; they do not represent a monophyletic group (the group of all descendants of a single common ancestral species), since swans and geese are not considered ducks. Ducks are mostly aquatic birds, and may be found in both fresh water and sea water. Ducks are sometimes confused with several types of unrelated water birds with similar forms, such as loons or divers, grebes, gallinules and coots. Etymology The word ''duck'' comes from Old English 'diver', a derivative of the verb 'to duck, bend down low as if to get under something, or dive', because of the way many species in the dabbling duck group feed by upending; compare with Dutch and German 'to dive'. This word replaced Old English / 'duck', possibly to avoid confusion w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird
Birds are a group of warm-blooded vertebrates 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. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have 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 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 swim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order (biology)
Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Miocene
The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to 15.97 ± 0.05 Ma (million years ago). It was preceded by the Oligocene epoch. As the climate started to get cooler, the landscape started to change. New mammals evolved to replace the extinct animals of the Oligocene epoch. The first members of the hyena and weasel family started to evolve to replace the extinct ''Hyaenodon'', entelodonts and bear-dogs. The chalicotheres survived the Oligocene epoch. A new genus of entelodont called ''Daeodon'' evolved in order to adapt to the new habitats and hunt the new prey animals of the Early Miocene epoch; it quickly became the top predator of North America. But it became extinct due to competition from ''Amphicyon'', a newcomer from Eurasia. ''Amphicyon'' bested ''Daeodon'' because the bear-dog's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goose
A goose ( : geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (the grey geese and white geese) and ''Branta'' (the black geese). Some other birds, mostly related to the shelducks, have "goose" as part of their names. More distantly related members of the family Anatidae are swans, most of which are larger than true geese, and ducks, which are smaller. The term "goose" may refer to either a male or female bird, but when paired with "gander", refers specifically to a female one (the latter referring to a male). Young birds before fledging are called goslings. The collective noun for a group of geese on the ground is a gaggle; when in flight, they are called a skein, a team, or a wedge; when flying close together, they are called a plump. Etymology The word "goose" is a direct descendant of,''*ghans-''. In Germanic languages, the root gave Old English ''gōs'' with the plural ''gēs'' and ''gandres'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coot
Coots are medium-sized water birds that are members of the rail family, Rallidae. They constitute the genus ''Fulica'', the name being the Latin term for "coot". Coots have predominantly black plumage, and—unlike many rails—they are usually easy to see, often swimming in open water. They are close relatives of the moorhen. However, the Coot typically appears 'dumpier' and lacks the distinctive red frontal face of the moorhen. Taxonomy and systematics The genus ''Fulica'' was introduced in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his ''Systema Naturae''. The genus name is the Latin word for a Eurasian coot. The name was used by the Swiss naturalist Conrad Gessner in 1555. The type species is the Eurasian coot. A group of coots are referred to as a ''covert'' or ''cover''. Species The genus contains 10 extant species and one which is now extinct. Extinct species Recently extinct species * ''Fulica newtonii'' Milne-Edwards, 1867 – Masca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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