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Sharp-shinned Hawk
The sharp-shinned hawk (''Accipiter striatus'') is a small hawk, with males being the smallest hawks in the United States and Canada, but with the species averaging larger than some Neotropical realm, Neotropical species, such as the tiny hawk. The Taxonomy (biology), taxonomy is far from resolved, with some authorities considering the southern taxon, taxa to represent three separate species: white-breasted hawk (''A. chionogaster''), plain-breasted hawk (''A. ventralis''), and rufous-thighed hawk (''A. erythronemius''). The American Ornithological Society keeps all four variations conspecific. Taxonomy The sharp-shinned hawk is sometimes separated into four species, with the northern group (''see distribution'') retaining both the scientific name and the common name: sharp-shinned hawk (''A. striatus''). In addition to the nominate taxon (''A. s. striatus''), it includes subspecies ''perobscurus'', ''velox'', ''suttoni'', ''madrensis'', ''fringilloides'', and ''venator''. The t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Jean Pierre Vieillot
Louis Pierre Vieillot (10 May 1748, Yvetot – 24 August 1830, Sotteville-lès-Rouen) was a French ornithologist. Vieillot is the author of the first scientific descriptions and Linnaean names of a number of birds, including species he collected himself in the West Indies and North America and South American species discovered but not formally named by Félix de Azara and his translator Sonnini de Manoncourt. He was among the first ornithologists to study changes in plumage and one of the first to study live birds. At least 77 of the genera erected by Vieillot are still in use. Biography Vieillot was born in Yvetot. He represented his family's business interests in Saint-Domingue (Haiti) on Hispaniola, but fled to the United States during the Haitian rebellions that followed the French Revolution. On Buffon's advice, he collected material for the ''Histoire naturelle des oiseaux de l'Amérique Septentrionale,'' the first two volumes of which were published in France beginning i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allopatric
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow. Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo genetic changes as they become subjected to different selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent the exchange of genetic information between t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymorphism (biology)
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Ford E.B. 1965. ''Genetic polymorphism''. Faber & Faber, London. Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accipiter Striatus Juvenile
''Accipiter'' is a genus of birds of prey in the family Accipitridae. With 51 recognized species it is the most diverse genus in its family. Most species are called goshawks or sparrowhawks, although almost all New World species (excepting the northern goshawk) are simply known as hawks. They can be anatomically distinguished from their relatives by the lack of a procoracoid foramen. Two small and aberrant species usually placed here do possess a large procoracoid foramen and are also distinct as regards DNA sequence. They may warrant separation in the old genus ''Hieraspiza''.Olson (2006) Extant accipiters range in size from the little sparrowhawk (''A. minullus''), in which the smallest males measure long, span across the wings and weigh , to the northern goshawk (''A. gentilis''), in which the largest females measure long, span across the wings, and weigh . These birds are slender with short, broad, rounded wings and a long tail which helps them maneuver in flight. They ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juvenile (organism)
A juvenile is an individual organism that has not yet reached its adult form, sexual maturity or size. Juveniles can look very different from the adult form, particularly in colour, and may not fill the same niche as the adult form. In many organisms the juvenile has a different name from the adult (see List of animal names). Some organisms reach sexual maturity in a short metamorphosis, such as eclosion in many insects. For others, the transition from juvenile to fully mature is a more prolonged process—puberty in humans and other species, for example. In such cases, juveniles during this transformation are sometimes called subadults. Many invertebrates, on reaching the adult stage, are fully mature and their development and growth stops. Their juveniles are larvae or nymphs. In vertebrates and some invertebrates (e.g. spiders), larval forms (e.g. tadpoles) are usually considered a development stage of their own, and "juvenile" refers to a post-larval stage that is not full ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iris (anatomy)
In humans and most mammals and birds, the iris (plural: ''irides'' or ''irises'') is a thin, annular structure in the eye, responsible for controlling the diameter and size of the pupil, and thus the amount of light reaching the retina. Eye color is defined by the iris. In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm. Structure The iris consists of two layers: the front pigmented fibrovascular layer known as a stroma and, beneath the stroma, pigmented epithelial cells. The stroma is connected to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles ( dilator pupillae), which pull the iris radially to enlarge the pupil, pulling it in folds. The sphincter pupillae is the opposing muscle of the dilator pupillae. The pupil's diameter, and thus the inner border of the iris, changes size when constricting or dilating. The outer border of the iris does not change size. The constricti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloaca
In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, and a few mammals ( monotremes, tenrecs, golden moles, and marsupial moles), have this orifice, from which they excrete both urine and feces; this is in contrast to most placental mammals, which have two or three separate orifices for evacuation. Excretory openings with analogous purpose in some invertebrates are also sometimes referred to as cloacae. Mating through the cloaca is known as cloacal copulation, commonly referred to as cloacal kiss. The cloacal region is also often associated with a secretory organ, the cloacal gland, which has been implicated in the scent-marking behavior of some reptiles, marsupials, amphibians, and monotremes. Etymology The word is from the Latin verb ''cluo'', "(I) cleanse", thus the noun ''cloaca'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covert Feather
A covert feather or tectrix on a bird is one of a set of feathers, called coverts (or ''tectrices''), which, as the name implies, cover other feathers. The coverts help to smooth airflow over the wings and tail. Ear coverts The ear coverts are small feathers behind the bird's eye which cover the ear opening (the ear of a bird has no external features) Tail coverts The uppertail and undertail coverts cover the base of the tail feathers above and below. Sometimes these coverts are more specialised. The "tail" of a peacock is made of very elongated uppertail coverts. Wing coverts The upperwing coverts fall into two groups: those on the inner wing, which overlay the secondary flight feathers, known as the secondary coverts, and those on the outerwing, which overlay the primary flight feathers, the primary coverts. Within each group, the feathers form a number of rows. The feathers of the outermost, largest, row are termed greater (primary-/secondary-) coverts; those in the next row ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tawny (color)
Tawny (also called tenné) is a light brown to brownish-orange color. Etymology The word means "tan-colored", from Anglo-Norman ''tauné'' "associated with the brownish-yellow of tanned leather", from Old French ''tané'' "to tan hides", from Medieval Latin ''tannare'', from ''tannum'' "crushed oak bark", used in tanning leather, probably from a Celtic source (e.g. Breton ''tann'', "oak tree"). Electronic definitions of tawny A digitized version of the 1912 book ''Color Standards And Color Nomenclature'' lists tawny as AE6938, tawny-olive as 826644 or 967117, ochraceous-tawny as BE8A3D or 996515, and vinaceous-tawny as B4745E. HP Labs' ''Online Color Thesaurus'', which lists colors found through their ''Color Naming Experiment'', gives tawny as CC7F3B, noting it is "rarely used", and lists its synonyms as: light chocolate, caramel, light brown, and camel. Dictionary of Color lists tawny as AE6938 or A67B5B, and tawny birch as A87C6D, A67B5B or 958070. It also lists "lion t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cere
The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food, Courtship#Courtship in the animal kingdom, courtship, and feeding young. The terms ''beak'' and ''Rostrum (anatomy), rostrum'' are also used to refer to a similar mouth part in some ornithischians, pterosaurs, cetaceans, dicynodonts, anuran tadpoles, monotremes (i.e. echidnas and platypuses, which have a beak-like structure), Sirenidae, sirens, Tetraodontidae, pufferfish, billfishes and Cephalopod beak, cephalopods. Although beaks vary significantly in size, shape, color and texture, they share a similar underlying structure. Two bony projections – the upper and lower mandibles – are covered with a thin keratinized layer of epidermis known as the rhamphotheca. In most species, two holes called ''nares'' lead to the respiratory system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remiges
Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tail are called rectrices (), singular rectrix (). The primary function of the flight feathers is to aid in the generation of both thrust and lift, thereby enabling flight. The flight feathers of some birds have evolved to perform additional functions, generally associated with territorial displays, courtship rituals or feeding methods. In some species, these feathers have developed into long showy plumes used in visual courtship displays, while in others they create a sound during display flights. Tiny serrations on the leading edge of their remiges help owls to fly silently (and therefore hunt more successfully), while the extra-stiff rectrices of woodpeckers help them to brace against tree trunks as they hammer on them. Even flightless birds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accipiter
''Accipiter'' is a genus of Bird of prey, birds of prey in the family Accipitridae. With 51 recognized species it is the most diverse genus in its family. Most species are called goshawks or sparrowhawks, although almost all New World species (excepting the northern goshawk) are simply known as hawks. They can be anatomically distinguished from their relatives by the lack of a coracoid, procoracoid foramen. Two small and aberrant species usually placed here do possess a large procoracoid foramen and are also distinct as regards DNA sequence. They may warrant separation in the old genus ''Hieraspiza''.Olson (2006) Extant accipiters range in size from the little sparrowhawk (''A. minullus''), in which the smallest males measure long, span across the wings and weigh , to the northern goshawk (''A. gentilis''), in which the largest females measure long, span across the wings, and weigh . These birds are slender with short, broad, rounded wings and a long tail which helps them mane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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