|
Altricial
Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. These categories form a continuum, without distinct gaps between them. In fish, this often refers to the presence or absence of a stomach: precocial larvae have one at the onset of first feeding whereas altricial fish do not. Depending on the species, the larvae may develop a functional stomach during metamorphosis (gastric) or remain stomachless (agastric). Precociality Precocial young have open eyes, hair or down, large brains, and are immediately mobile and somewhat able to flee from or defend themselves against predators. For example, with ground-nesting birds such as ducks or turkeys, the young are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nidifugous
In biology, nidifugous ( , ) organisms are those that leave the nest shortly after hatching or birth. The term is derived from Latin ''nidus'' for "nest" and ''fugere'', meaning "to flee". The terminology is most often used to describe birds and was introduced by Lorenz Oken in 1816. The chicks of birds in many families, such as the waders, waterfowl, and gamebirds, are usually nidifugous. The opposite of nidifugous organisms are nidicolous ( ; from Latin ''nidus'' "nest" and ''-colus'' "inhabiting") organisms; a nidicolous organism is one which stays at its birthplace for a long time because it depends on its parents for food, protection, and the learning of survival skills. Examples of nidicolous species include mammals and many species of birds. During the life span, the brain of a nidicolous animal expands 8–10 times its initial size; in nidifugous animals, it expands from 1.5 to 2.5 times. Relation to precociality and altriciality Two other terms are also used by scientist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird
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. There are over 11,000 living species and they are split into 44 Order (biology), orders. More than half are passerine or "perching" birds. Birds have Bird wing, 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 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enantiornithes
The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct Avialae, avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over seventy species of Enantiornithes have been named, but some names represent only single bones, so it is likely that not all are valid. The Enantiornithes became extinct at the Cretaceous–Paleogene boundary, along with Hesperornithes and all other non-avian dinosaurs. Discovery and naming The first Enantiornithes to be discovered were incorrectly referred to modern bird groups. For example, the first known species of Enantiornithes, ''Gobipteryx minuta'', was originally considered a paleognath related to ostriches and tinamou. The Enantiornithes were first recognized as a distinct lineage, or "subclass" of birds, by Cyril A. Walker in 1981. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupial
Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a relatively undeveloped state and then nurtured within a pouch on their mother's abdomen. Extant marsupials encompass many species, including Kangaroo, kangaroos, Koala, koalas, Opossum, opossums, Phalangeriformes, possums, Tasmanian devil, Tasmanian devils, Wombat, wombats, Wallaby, wallabies, and Bandicoot, bandicoots. Marsupials constitute a clade stemming from the last common ancestor of extant Metatheria, which encompasses all mammals more closely related to marsupials than to Placentalia, placentals. The evolutionary split between placentals and marsupials occurred 125-160 million years ago, in the Middle Jurassic-Early Cretaceous period. Presently, close to 70% of the 334 extant marsupial species are concentrated on the Australian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birth
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the fetus at a developmental stage when it is ready to feed and breathe. In some species, the offspring is precocial and can move around almost immediately after birth but in others, it is altricial and completely dependent on parenting. In marsupials, the fetus is born at a very immature stage after a short gestation and develops further in its mother's womb Pouch (marsupial), pouch. It is not only mammals that give birth. Some reptiles, amphibians, fish and invertebrates carry their developing young inside them. Some of these are Ovoviviparity, ovoviviparous, with the eggs being hatched inside the mother's body, and others are Viviparity, viviparous, with the embryo developing inside their body, as in the case of mammals. Human childbirth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passerine
A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped') which includes more than half of all bird species. Sometimes known as perching birds, passerines generally have an anisodactyl arrangement of their toes (three pointing forward and one back), which facilitates perching. With more than 140 families and some 6,500 identified species, Passeriformes is the largest order of birds and one of the most diverse clades of terrestrial vertebrates, representing 60% of birds.Ericson, P.G.P. et al. (2003Evolution, biogeography, and patterns of diversification in passerine birds ''J. Avian Biol'', 34:3–15.Selvatti, A.P. et al. (2015"A Paleogene origin for crown passerines and the diversification of the Oscines in the New World" ''Molecular Phylogenetics and Evolution'', 88:1–15. Passerines are divided into three suborders: New Zealand wrens; Suboscines, primarily found in North and South America; and songbirds. Passerines originated in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuckoo
Cuckoos are birds in the Cuculidae ( ) family, the sole taxon in the order Cuculiformes ( ). The cuckoo family includes the common or European cuckoo, roadrunners, koels, malkohas, couas, coucals, and anis. The coucals and anis are sometimes separated as distinct families, the Centropodidae and Crotophagidae, respectively. The cuckoo order Cuculiformes is one of three that make up the Otidimorphae, the other two being the turacos and the bustards. The family Cuculidae contains 150 species, which are divided into 33 genera. The cuckoos are generally medium-sized, slender birds. Most species live in trees, though a sizeable minority are ground-dwelling. The family has a cosmopolitan distribution; the majority of species are tropical. Some species are migratory. The cuckoos feed on insects, insect larvae, and a variety of other animals, as well as fruit. Some species are brood parasites, laying their eggs in the nests of other species and giving rise to the terms " cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodpecker
Woodpeckers are part of the bird family (biology), family Picidae, which also includes the piculets, wrynecks and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar and the extreme polar regions. Most species live in forests or woodland habitats, although a few species are known that live in treeless areas, such as rocky hillsides and deserts, and the Gila woodpecker specializes in exploiting cacti. Members of this family are chiefly known for their characteristic behaviour. They mostly forage for insect prey on the trunks and branches of trees, and often communicate by drumming with their beaks, producing a reverberatory sound that can be heard at some distance. Some species vary their diet with fruits, birds' eggs, small animals, tree sap, human scraps, and carrion. They usually nest and roost in holes that they excavate in tree trunks, and their abandoned holes are of importance to other cavity-nesting birds. They ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Down Feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as Down jacket, jackets, bedding (duvets and featherbeds), pillows and sleeping bags. The discovery of feathers trapped in ancient amber suggests that some species of non-avian dinosaur likely possessed down-like feathers. Description and etymology The word ''down'' comes from the Old Norse word ''dúnn'', which had the same meaning as its modern equivalent. The down feather is considered to be the most "straightforward" of all feather types. It has a short or vestigial rachis (shaft), few barb (feather), barbs, and barbules that lack hooks. There are three types of down: natal down, body down and powder down. Natal down is the layer of down feathers that cover most birds at some point in their early developmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megapode
The megapodes, also known as incubator birds or mound-builders, are stocky, medium-large, chicken-like birds with small heads and large feet in the family Megapodiidae. Their name literally means "large foot" and is a reference to the heavy legs and feet typical of these terrestrial birds. All are browsers, and all except the malleefowl occupy wooded habitats. Most are brown or black in color. Megapodes are superprecocial, hatching from their eggs in the most mature condition of any bird. They hatch with open eyes, bodily coordination and strength, full wing feathers, and downy body feathers, and are able to run, pursue prey and, in some species, fly on the day they hatch. Etymology From the Greek ( = ''great'') and , ( = ''foot''). Description Megapodes are medium-sized to large terrestrial birds with large legs and feet with sharp claws. Megapodes are of three kinds: scrub fowl, brush turkeys, and mallee fowl or lowan. The largest members of the clade are the species of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
