A covert feather or tectrix on a bird is one of a set of feathers, called coverts, which, as the name implies, cover other feathers. The coverts help to smooth airflow over tail; the ear coverts are small feathers behind the bird's eye which cover the ear opening 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 elongated uppertail coverts. The upperwing coverts fall into two groups: those on the inner wing, which overlay the secondary flight feathers, known as the secondary coverts, 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, row are termed greater coverts. The underwing has corresponding sets of coverts. In addition, the front edge of the wing is covered with a group of feathers called the marginal coverts. Within each group of wing coverts, the rows of feathers overlap each other like roof tiles.
Flight feather Mullarney, Killian. Collins Bird Guide. London: HarperCollins. ISBN 0-00-219728-6
The pavonine quetzal is a species of bird in the family Trogonidae, the trogons. It is known at the peacock trogon, red-billed train bearer, or viuda pico rojo in Spanish; the pavonine quetzal lives in the Neotropics, more in the northern region of the Amazon basin, spreading from Colombia to Bolivia. The most notable characteristics helpful in identifying this bird are its plumage, red beak, its distribution - it is the only quetzal occupying the lowland rainforest east of the Andes; the pavonine quetzal belongs to the Trogon family that falls in Trogoniformes, which differ from other birds by the unique toe arrangement. As opposed to woodpeckers who have the first and fourth toe facing backwards, trogons have the first and second toe positioned posteriorly, while the third and fourth remain anterior to the foot, their toe arrangement makes them poorly suited for walking or hopping, so trogons are most seen flying or perched below canopy level. Some species, like the endangered resplendent quetzal have evolved some elaborate ornamental feathers, exemplifying how most of the species in this family have avoided developed to become the best fliers.
Trogons fly for short periods of time, use quick, undulating wingbeats to move them from one perch to the next. Among other things, their inefficient flying limits them to migrate short distances, if at all. However, we find trogons across the globe in a pan-tropical distribution, from 35°N to 35°S, spanning all the way from sea level up to 3500m in elevation. Across this elevational gradient, different species occupy the various habitats, though all species are frugivores, insectivores, or a combination of the two. Within the trogon family, there are two subfamilies: African trogons. In the non-African trogons, the two front toes are always at least fused, which serves them like spades in excavation of nesting sites. P. pavoninus falls within the tribe Trogonini, which only includes the new world trogons and the quetzals. A few other defining characteristics of this tribe include physical descriptors such as uniform and iridescent green to blue head, upper breast and upper parts. While different molecular markers lead to debate about the basal relationship of trogons, the most common resulting phylogenies indicate that the African trogons are basal to the Indomalayan and Neotropical trogons, the latter two are sister taxa.
Additionally, the Trogonini appear certainly to be monophyletic. In other studies, the phylogeny produces similar relationships, placing the African trogons basally, followed by the Indomalayan trogons the quetzals, the new world trogons. Quetzals, genus Pharomachrus, distinguish themselves from other new world trogons by two main morphological traits. First, the absence of serrations on maxilla, having a simple notch near the tip of the bill instead, in addition to an undulating margin of the mandible. Second, their nostrils rest closer together, hide beneath an overhanging operculum. Quetzals weigh in heavy around 150 to 250g, they feed on fruit. Male quetzals have four noticeably elongated and iridescent feathers that meet or reach beyond the tail. Like many other quetzals, pavonine quetzals are brilliantly coloured, exhibiting some sexual dichromatism, with the females being noticeable duller than the males. Overall, they resemble most the golden-headed quetzal. Feathers of the back, median wing coverts and upper tail coverts are all iridescent green with a black base and some that are edged with bronze.
The feathers on the head give a golden brown to golden green appearance, while the belly stands out as a brilliant red. The remaining feathers on the wings and thighs are all black; the bill recalls the red of the belly, yellows to the tip. The iris is reddish to brownish, while the legs and toes are yellowish to brownish. In this species, the nape feathers rather than the forehead feathers form a bristly crest. Additionally, the lore feathers are of normal length. At the wing, the upper wing coverts grow moderately pointed, reaching over the primaries. At the tail, the longest of the upper tail coverts grow long and pointed, extending to or beyond the retrices, covering them entirely; the retrices, on the other hand, grow rounded at the tips and taper in length along the three outer pairs, while the six inner pairs grow to a more blunt or truncated end. Similar to male, with most significant differences in the brilliance of the plumage, more buff colouring, patterned tails; the head becomes brown or greyish, the bill is much more grey bill with a black tip.
The tips of the wing feathers turn much more buff, the abdomen develops into more of a brownish red. The retrices have an alternating bar pattern of black and white, the upper tail coverts are shorter than in males; the pavonine quetzal resides year-round in the Amazon basin. Its range crosses the borders of Brazil and Venezuela, southeastern Colombia, eastern Ecuador and Peru, northern Bolivia. More it is found in the states of Amazonas and Bolívar in Venezu
Pharomachrus is a genus of birds in the family Trogonidae. Pharomachrus is from Ancient Greek pharos, "mantle", makros, "long", referring to the wing and tail coverts of the resplendent quetzal; the five species of this genus and the eared quetzal, the only living member of the genus Euptilotis, together make up a group of colourful birds called quetzals
Vertebrates comprise all species of animals within the subphylum Vertebrata. Vertebrates represent the overwhelming majority of the phylum Chordata, with about 69,276 species described. Vertebrates include the jawless fishes and jawed vertebrates, which include the cartilaginous fishes and the bony fishes; the bony fishes in turn, cladistically speaking include the tetrapods, which include amphibians, reptiles and mammals. Extant vertebrates range in size from the frog species Paedophryne amauensis, at as little as 7.7 mm, to the blue whale, at up to 33 m. Vertebrates make up less than five percent of all described animal species; the vertebrates traditionally include the hagfish, which do not have proper vertebrae due to their loss in evolution, though their closest living relatives, the lampreys, do. Hagfish do, possess a cranium. For this reason, the vertebrate subphylum is sometimes referred to as "Craniata" when discussing morphology. Molecular analysis since 1992 has suggested that hagfish are most related to lampreys, so are vertebrates in a monophyletic sense.
Others consider them a sister group of vertebrates in the common taxon of craniata. The word vertebrate derives from the Latin word vertebratus. Vertebrate is derived from the word vertebra, which refers to any of the bones or segments of the spinal column. All vertebrates are built along the basic chordate body plan: a stiff rod running through the length of the animal, with a hollow tube of nervous tissue above it and the gastrointestinal tract below. In all vertebrates, the mouth is found at, or right below, the anterior end of the animal, while the anus opens to the exterior before the end of the body; the remaining part of the body continuing after the anus forms a tail with vertebrae and spinal cord, but no gut. The defining characteristic of a vertebrate is the vertebral column, in which the notochord found in all chordates has been replaced by a segmented series of stiffer elements separated by mobile joints. However, a few vertebrates have secondarily lost this anatomy, retaining the notochord into adulthood, such as the sturgeon and coelacanth.
Jawed vertebrates are typified by paired appendages, but this trait is not required in order for an animal to be a vertebrate. All basal vertebrates breathe with gills; the gills are carried right behind the head, bordering the posterior margins of a series of openings from the pharynx to the exterior. Each gill is supported by a cartilagenous or bony gill arch; the bony fish have three pairs of arches, cartilaginous fish have five to seven pairs, while the primitive jawless fish have seven. The vertebrate ancestor no doubt had more arches than this, as some of their chordate relatives have more than 50 pairs of gills. In amphibians and some primitive bony fishes, the larvae bear external gills, branching off from the gill arches; these are reduced in adulthood, their function taken over by the gills proper in fishes and by lungs in most amphibians. Some amphibians retain the external larval gills in adulthood, the complex internal gill system as seen in fish being irrevocably lost early in the evolution of tetrapods.
While the more derived vertebrates lack gills, the gill arches form during fetal development, form the basis of essential structures such as jaws, the thyroid gland, the larynx, the columella and, in mammals, the malleus and incus. The central nervous system of vertebrates is based on a hollow nerve cord running along the length of the animal. Of particular importance and unique to vertebrates is the presence of neural crest cells; these are progenitors of stem cells, critical to coordinating the functions of cellular components. Neural crest cells migrate through the body from the nerve cord during development, initiate the formation of neural ganglia and structures such as the jaws and skull; the vertebrates are the only chordate group to exhibit cephalisation, the concentration of brain functions in the head. A slight swelling of the anterior end of the nerve cord is found in the lancelet, a chordate, though it lacks the eyes and other complex sense organs comparable to those of vertebrates.
Other chordates do not show any trends towards cephalisation. A peripheral nervous system branches out from the nerve cord to innervate the various systems; the front end of the nerve tube is expanded by a thickening of the walls and expansion of the central canal of spinal cord into three primary brain vesicles: The prosencephalon and rhombencephalon, further differentiated in the various vertebrate groups. Two laterally placed eyes form around outgrowths from the midbrain, except in hagfish, though this may be a secondary loss; the forebrain is well developed and subdivided in most tetrapods, while the midbrain dominates in many fish and some salamanders. Vesicles of the forebrain are paired, giving rise to hemispheres like the cerebral hemispheres in mammals; the resulting anatomy of the central nervous system, with a single hollow nerve cord topped by a series of vesicles, is unique to vertebrates. All invertebrates with well-developed brains, such as insects and squids, have a ventral rather than dorsal system of ganglions, with a split brain stem running on each side of the mouth or gut.
Vertebrates originated about 525 million years ago during the Cambrian explosion, which saw
Nahuatl, known as Aztec, is a language or group of languages of the Uto-Aztecan language family. Varieties of Nahuatl are spoken by about 1.7 million Nahua peoples, most of whom live in central Mexico. Nahuatl has been spoken in central Mexico since at least the seventh century CE, it was the language of the Aztecs, who dominated what is now central Mexico during the Late Postclassic period of Mesoamerican history. During the centuries preceding the Spanish conquest of the Aztec Empire, the Aztecs had expanded to incorporate a large part of central Mexico, their influence caused the variety of Nahuatl spoken by the residents of Tenochtitlan to become a prestige language in Mesoamerica. At the conquest, with the introduction of the Latin alphabet, Nahuatl became a literary language, many chronicles, works of poetry, administrative documents and codices were written in it during the 16th and 17th centuries; this early literary language based on the Tenochtitlan variety has been labeled Classical Nahuatl, is among the most studied and best-documented languages of the Americas.
Today, Nahuan languages are spoken in scattered communities in rural areas throughout central Mexico and along the coastline. There are considerable differences among varieties, some are not mutually intelligible. Huasteca Nahuatl, with over one million speakers, is the most-spoken variety. All varieties have been subject to varying degrees of influence from Spanish. No modern Nahuan languages are identical to Classical Nahuatl, but those spoken in and around the Valley of Mexico are more related to it than those on the periphery. Under Mexico's General Law of Linguistic Rights of the Indigenous Peoples promulgated in 2003, Nahuatl and the other 63 indigenous languages of Mexico are recognized as lenguas nacionales in the regions where they are spoken, enjoying the same status as Spanish within their regions. Nahuan languages exhibit a complex morphology characterized by polysynthesis and agglutination. Through a long period of coexistence with the other indigenous Mesoamerican languages, they have absorbed many influences, coming to form part of the Mesoamerican language area.
Many words from Nahuatl have been borrowed into Spanish and, from there, were diffused into hundreds of other languages. Most of these loanwords denote things indigenous to central Mexico which the Spanish heard mentioned for the first time by their Nahuatl names. English words of Nahuatl origin include "avocado", "chayote", "chili", "chocolate", "atlatl", "coyote", "peyote", "axolotl" and "tomato"; as a language label, the term "Nahuatl" encompasses a group of related languages or divergent dialects within the Nahuan branch of the Uto-Aztecan language family. The Mexican Instituto Nacional de Lenguas Indígenas recognizes 30 individual varieties within the "language group" labeled Nahuatl; the Ethnologue recognizes 28 varieties with separate ISO codes. Sometimes the label is used to include the Pipil language of El Salvador. Regardless of whether "Nahuatl" is considered to label a dialect continuum or a group of separate languages, the varieties form a single branch within the Uto-Aztecan family, descended from a single Proto-Nahuan language.
Within Mexico, the question of whether to consider individual varieties to be languages or dialects of a single language is political. This article focuses on describing the general history of the group and on giving an overview of the diversity it encompasses. For details on individual varieties or subgroups, see the individual articles. In the past, the branch of Uto-Aztecan to which Nahuatl belongs has been called "Aztecan". From the 1990s onward, the alternative designation "Nahuan" has been used as a replacement in Spanish-language publications; the Nahuan branch of Uto-Aztecan is accepted as having two divisions: "General Aztec" and Pochutec. General Aztec encompasses the Pipil languages. Pochutec is a scantily attested language, which became extinct in the 20th century, which Campbell and Langacker classify as being outside of general Aztec. Other researchers have argued that Pochutec should be considered a divergent variant of the western periphery."Nahuatl" denotes at least Classical Nahuatl together with related modern languages spoken in Mexico.
The inclusion of Pipil into the group is debated. Lyle Campbell classified Pipil as separate from the Nahuatl branch within general Aztecan, whereas dialectologists like Una Canger, Karen Dakin, Yolanda Lastra and Terrence Kaufman have preferred to include Pipil within the General Aztecan branch, citing close historical ties with the eastern peripheral dialects of General Aztec. Current subclassification of Nahuatl rests on research by Canger and Lastra de Suárez. Canger introduced the scheme of a Central grouping and two Peripheral groups, Lastra confirmed this notion, differing in some details. Canger & Dakin demonstrated a basic split between Eastern and Western branches of Nahuan, considered to reflect the oldest division of the proto-Nahuan speech community. Canger considered the central dialect area to be an innovative subarea within the Western branch, but in 2011, she suggested that it arose as an urban koiné language with features from both Western and Eastern dialect areas. Canger tentatively included dialects of La Huasteca in the Central group, while Lastra de Suárez places them in the Eastern Periphery, followed by Kaufman.
The terminology used to describe varieties of spoken Nahuatl is inconsistently applied. Many terms are used with multiple denotations, or a single dialect grou
The white-tipped quetzal is a species of bird in the family Trogonidae. It is found in Venezuela and Guyana. In Venezuela and Colombia, three separated ranges occur, its natural habitat is subtropical or tropical moist montane forests. Breeding predominantly occurs towards the conclusion of the dry season, within the Julian calendar’s first half. In the north coast of Columbia, this was referencing the beginning of May. Available nesting information was unavailable, there were subtle differences in egg color and size. Quetzel reproduction was described, there were qualitative variations for the colors. For nesting, this species tends to use non-native tree plantations. For nesting and reproduction, this species uses isolated trees; these nests were studied how it influences breeding. "White-tipped quetzal media". Internet Bird Collection. Photo.
The eared quetzal known as the eared trogon, is a near passerine bird in the trogon family, Trogonidae. It breeds in streamside pine-oak forests and canyons in the Sierra Madre Occidental of Mexico south to western Michoacán, it is sometimes seen as a vagrant to southeasternmost Arizona in the United States and has bred there. This range includes part of the Madrean Sky Islands region of southeastern Arizona, southwestern New Mexico, northern Sonora, it is a resident of the middle to upper levels of pine-oak woodlands and oak-conifer forests along streams. It nests 5–9 m high in an unlined shallow tree cavity selecting an old woodpecker hole. Nests have been observed in pine, fir and aspen trees. Limited excavation of the cavity is accomplished using the bill to dig into the rotten wood of the walls and opening. Quetzals differ from typical New World trogons in having iridescent wing coverts, less extensive fusion between the two forward-facing toes of their heterodactyl foot, broad tails with distinctly convex sides, eggs with pale blue shells.
They average larger in body size than typical trogons, the eggs and young develop more slowly. The eared quetzal is a primitive form, lacking the impressively long iridescent upper tail and wing coverts of members of the genus Pharomachrus. Body length is 33–36 cm. Both sexes have iridescent green backs, iridescent dark blue central tail feathers, outer tail feathers that are predominantly white terminally with a band of black at the base; the bill is dull gray with a darker band at the tip. The adult male has a blackish head, iridescent green breast, geranium red belly and undertail coverts; the adult female has a gray head and upper belly and less extensive red on the lower belly. Both sexes bear the wispy hair-like auricular plumes that give the species its name, though these are apparent in the field. Both head and bill appear rather small and narrow in comparison to those of typical trogons; the male's song is a series of whistled notes increasing in volume. Calls include low-intensity squeals rising in pitch, a loud squeal ending with a sharp "chuck," and a strident cackle given in flight.
Eared quetzals feed on insects, small vertebrates, fruit, including the warty red fruits of madrone trees. Caterpillars, katydids, small lizards, other prey are fed to the young. Like other trogons, eared quetzals pluck prey and fruit while hovering. Members of this species have been observed to exhibit aversion to large areas of conspicuous color on and near human observers, including white, red and blue; this suggests that the species-confidence hypothesis, which states that birds tend to be attracted to colors that match those found in their species and repelled by colors not found in their species, does not apply to eared quetzals. BirdLife Species Factsheet Eared quetzal photo VIREO Photo-High Res Photo Album: Thick-billed parrots and eared quetzals in Madera, Chihuahua