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Timberline Sparrow
The timberline sparrow (''Spizella breweri taverneri'') is a taxonomically controversial American sparrow. Usually treated as a subspecies of Brewer's sparrow, it is considered a distinct species ''Spizella taverneri'' by some authorities. While the timberline sparrow recognizably differs in some details, there is little reproductive isolation between the taxa. When it was still considered a species, it was listed as being of least concern by the IUCN.E.g. Baillie ''et al.'' (2004). Footnotes References * (2004): ''2004 IUCN Red List of Threatened Species. A Global Species Assessment.'' IUCN, Gland, Switzerland and Cambridge, UK. * {{Taxonbar, from=Q7804717 Spizella Birds described in 1925 Taxonomy articles created by Polbot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomical
In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a more inclusive group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain, kingdom, phylum (''division'' is sometimes used in botany in place of ''phylum''), class, order, family, genus, and species. The Swedish botanist Carl Linnaeus is regarded as the founder of the current system of taxonomy, as he developed a ranked system known as Linnaean taxonomy for categorizing organisms and binomial nomenclature for naming organisms. With advances in the theory, data and analytical technology of biological systematics, the Linnaean system has transformed into a system of modern biological classification intended to reflect the evolut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Sparrow
New World sparrows are a group of mainly New World passerine birds, forming the family Passerellidae. They are seed-eating birds with conical bills, brown or gray in color, and many species have distinctive head patterns. Although they share the name sparrow, New World sparrows are more closely related to Old World buntings than they are to the Old World sparrows (family Passeridae). New World sparrows are also similar in both appearance and habit to finches, with which they sometimes used to be classified. Taxonomy The genera now assigned to the family Passerellidae were previously included with the buntings in the family Emberizidae. A phylogenetic analysis of nuclear and mitochondrial DNA sequences published in 2015 found that the Passerellidae formed a monophyletic group that had an uncertain relationship to the Emberizidae. Emberizidae was therefore split and the family Passerellidae resurrected. It had originally been introduced, as the subfamily Passerellinae, by the Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brewer's Sparrow
Brewer's sparrow (''Spizella breweri'') is a small, slim species of American sparrow in the family Passerellidae. This bird was named after the ornithologist Thomas Mayo Brewer. Description and systematics Adults have grey-brown backs and speckled brown crowns, both with dark streaks, and a pale eye-ring. Their wings are brown with light wing bars and the underparts are pale grey. Their bill is pale with a dark tip and they have a long notched tail. They are similar in appearance to the clay-colored sparrow (''S. pallida'') but do not have a pale stripe on the crown or grey neck patch. Measurements: * Length: 5.1-5.9 in (13-15 cm) * Weight: 0.4-0.5 oz (11-14 g) * Wingspan: 7.1-7.9 in (18-20 cm) The male sings to defend a nesting territory. The song is a long varied mix of notes and trills. Males have two distinct types of songs – classified as short and long songs. There are two distinct subspecies: * Brewer's sparrow proper, ''Spizella breweri breweri'' :Found in brushy a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproductive Isolation
The mechanisms of reproductive isolation are a collection of evolutionary mechanisms, behaviors and physiological processes critical for speciation. They prevent members of different species from producing offspring, or ensure that any offspring are sterile. These barriers maintain the integrity of a species by reducing gene flow between related species.Strickberger, M. 1978. ''Genética''. Omega, Barcelona, España, p.: 874-879. .Futuyma, D. 1998. ''Evolutionary biology'' (3ª edición). Sinauer, Sunderland. The mechanisms of reproductive isolation have been classified in a number of ways. Zoologist Ernst Mayr classified the mechanisms of reproductive isolation in two broad categories: pre-zygotic for those that act before fertilization (or before mating in the case of animals) and post-zygotic for those that act after it.Mayr, E. 1963. ''Animal species and evolution''. Harvard University Press, Cambridge. The mechanisms are genetically controlled and can appear in species whose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxa
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Least Concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. They do not qualify as threatened, near threatened, or (before 2001) conservation dependent. Species cannot be assigned the "Least Concern" category unless they have had their population status evaluated. That is, adequate information is needed to make a direct, or indirect, assessment of its risk of extinction based on its distribution or population status. Evaluation Since 2001 the category has had the abbreviation "LC", following the IUCN 2001 Categories & Criteria (version 3.1). Before 2001 "least concern" was a subcategory of the "Lower Risk" category and assigned the code "LR/lc" or lc. Around 20% of least concern taxa (3261 of 15636) in the IUCN database still use the code "LR/lc", which indicates they have not been re-evaluate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spizella
The genus ''Spizella'' is a group of American sparrows in the family Passerellidae. These birds are fairly small and slim, with short bills, round heads and long wings. They are usually found in semi-open areas, and outside of the nesting season they often forage in small mixed flocks. Systematics This genus was formerly placed with the Old World buntings in the family Emberizidae. However, genetic studies revealed that New World sparrows formed a distinct clade and thus it was placed in the resurrected family Passerellidae. Species * Chipping sparrow, ''Spizella passerina'' * Clay-colored sparrow, ''Spizella pallida'' * Brewer's sparrow, ''Spizella breweri'' ** Timberline sparrow, ''Spizella breweri taverneri'' * Field sparrow, ''Spizella pusilla'' * Worthen's sparrow, ''Spizella wortheni'' * Black-chinned sparrow, ''Spizella atrogularis'' The American tree sparrow, ''Spizelloides arborea'', was formerly a member of this group, but is now placed in its own monotypic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birds Described In 1925
Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a four-chambered heart, and a strong yet lightweight Bird skeleton, skeleton. Birds live worldwide and range in size from the bee hummingbird to the Common ostrich, 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 Flightless bird, loss of flight in some birds, including ratites, penguins, and diverse endemism, endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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