Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres and have complex interactions with each other and their environments, forming intricate food webs. The category includes humans, but in colloquial use the term animal refers only to non-human animals; the study of non-human animals is known as zoology. Most living animal species are in the Bilateria, a clade whose members have a bilaterally symmetric body plan; the Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes and molluscs—and the deuterostomes, containing the echinoderms and chordates.
Life forms interpreted. Many modern animal phyla became established in the fossil record as marine species during the Cambrian explosion which began around 542 million years ago. 6,331 groups of genes common to all living animals have been identified. Aristotle divided animals into those with those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between animal taxa. Humans make use of many other animal species for food, including meat and eggs. Dogs have been used in hunting, while many aquatic animals are hunted for sport.
Non-human animals have appeared in art from the earliest times and are featured in mythology and religion. The word "animal" comes from the Latin animalis, having soul or living being; the biological definition includes all members of the kingdom Animalia. In colloquial usage, as a consequence of anthropocentrism, the term animal is sometimes used nonscientifically to refer only to non-human animals. Animals have several characteristics. Animals are eukaryotic and multicellular, unlike bacteria, which are prokaryotic, unlike protists, which are eukaryotic but unicellular. Unlike plants and algae, which produce their own nutrients animals are heterotrophic, feeding on organic material and digesting it internally. With few exceptions, animals breathe oxygen and respire aerobically. All animals are motile during at least part of their life cycle, but some animals, such as sponges, corals and barnacles become sessile; the blastula is a stage in embryonic development, unique to most animals, allowing cells to be differentiated into specialised tissues and organs.
All animals are composed of cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. During development, the animal extracellular matrix forms a flexible framework upon which cells can move about and be reorganised, making the formation of complex structures possible; this may be calcified, forming structures such as shells and spicules. In contrast, the cells of other multicellular organisms are held in place by cell walls, so develop by progressive growth. Animal cells uniquely possess the cell junctions called tight junctions, gap junctions, desmosomes. With few exceptions—in particular, the sponges and placozoans—animal bodies are differentiated into tissues; these include muscles, which enable locomotion, nerve tissues, which transmit signals and coordinate the body. There is an internal digestive chamber with either one opening or two openings. Nearly all animals make use of some form of sexual reproduction, they produce haploid gametes by meiosis.
These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement, it first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm develops between them; these germ layers differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. In some species, such as the splendid fairywren, females benefit by mating with multiple males, thus producing more offspring of higher genetic quality; some animals are capable of asexual reproduction, which results
Birds known as Aves, are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, a strong yet lightweight skeleton. Birds range in size from the 5 cm bee hummingbird to the 2.75 m ostrich. They rank as the world's most numerically-successful class of tetrapods, with ten thousand living species, more than half of these being passerines, sometimes known as perching birds. Birds have wings which are less developed depending on the species. Wings, which evolved from forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in flightless birds, including ratites and diverse endemic island species of birds; the digestive and respiratory systems of birds are uniquely adapted for flight. Some bird species of aquatic environments seabirds and some waterbirds, have further evolved for swimming; the fossil record demonstrates that birds are modern feathered dinosaurs, having evolved from earlier feathered dinosaurs within the theropod group, which are traditionally placed within the saurischian dinosaurs.
The closest living relatives of birds are the crocodilians. Primitive bird-like dinosaurs that lie outside class Aves proper, in the broader group Avialae, have been found dating back to the mid-Jurassic period, around 170 million years ago. Many of these early "stem-birds", such as Archaeopteryx, were not yet capable of powered flight, many retained primitive characteristics like toothy jaws in place of beaks, long bony tails. DNA-based evidence finds that birds diversified around the time of the Cretaceous–Palaeogene extinction event 66 million years ago, which killed off the pterosaurs and all the non-avian dinosaur lineages, but birds those in the southern continents, survived this event and migrated to other parts of the world while diversifying during periods of global cooling. This makes them the sole surviving dinosaurs according to cladistics; some birds corvids and parrots, are among the most intelligent animals. Many species annually migrate great distances. Birds are social, communicating with visual signals and bird songs, participating in such social behaviours as cooperative breeding and hunting and mobbing of predators.
The vast majority of bird species are monogamous for one breeding season at a time, sometimes for years, but for life. Other species have breeding systems that are polygynous or polyandrous. Birds produce offspring by laying eggs, they are laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching; some birds, such as hens, lay eggs when not fertilised, though unfertilised eggs do not produce offspring. Many species of birds are economically important as food for human consumption and raw material in manufacturing, with domesticated and undomesticated birds being important sources of eggs and feathers. Songbirds and other species are popular as pets. Guano is harvested for use as a fertiliser. Birds prominently figure throughout human culture. About 120–130 species have become extinct due to human activity since the 17th century, hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them.
Recreational birdwatching is an important part of the ecotourism industry. The first classification of birds was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae. Carl Linnaeus modified that work in 1758 to devise the taxonomic classification system in use. Birds are categorised as the biological class Aves in Linnaean taxonomy. Phylogenetic taxonomy places Aves in the dinosaur clade Theropoda. Aves and a sister group, the clade Crocodilia, contain the only living representatives of the reptile clade Archosauria. During the late 1990s, Aves was most defined phylogenetically as all descendants of the most recent common ancestor of modern birds and Archaeopteryx lithographica. However, an earlier definition proposed by Jacques Gauthier gained wide currency in the 21st century, is used by many scientists including adherents of the Phylocode system. Gauthier defined Aves to include only the crown group of the set of modern birds; this was done by excluding most groups known only from fossils, assigning them, instead, to the Avialae, in part to avoid the uncertainties about the placement of Archaeopteryx in relation to animals traditionally thought of as theropod dinosaurs.
Gauthier identified four different definitions for the same biological name "Aves", a problem. Gauthier proposed to reserve the term Aves only for the crown group consisting of the last common ancestor of all living birds and all of its descendants, which corresponds to meaning number 4 below, he assigned other names to the other groups. Aves can mean all archosaurs closer to birds than to crocodiles Aves can mean those advanced archosaurs with feathers Aves can mean those feathered dinosaurs that fly Aves can mean the last common ancestor of all the living birds and all of its descendants (a "c
The violet sabrewing is a large hummingbird native to southern Mexico and Central America as far south as Costa Rica and western Panama. It is a species of the understory and edges of mountain forests near streams; the female violet sabrewing lays two white eggs in a large cup nest on a low horizontal branch over a stream. The violet sabrewing is 15 cm long, it is the largest hummingbird found outside of the largest sabrewing. The adult male is deep violet, with a dark green wing coverts; the shafts of the male's outer primary flight feathers are thickened and flattened to give the distinctive feature which gives the sabrewings their English and scientific names. The three outer pairs of feathers of the otherwise black tail are white; the female is grey below apart from a violet throat. Young violet sabrewings have buff edges to the feathers and lack any violet, although juvenile males may be dusky green-blue below; the food of this species is nectar, taken from undergrowth flowers with Heliconias and bananas as favourites.
The males are less territorial at flowers than their size would suggest. The call of the violet sabrewing is a sharp twitter, the song of the male, given at leks of up to ten males, is a high-pitched piercing cheep tsew cheep tik-tik tsew. Stiles, F. Gary. A Guide to the Birds of Costa Rica. Comstock Publishing Associates. ISBN 0-8014-9600-4. "Violet sabrewing media". Internet Bird Collection. Violet sabrewing Stamps at birdstamps.org Violet sabrewing photo gallery at VIREO Violet sabrewing species account at Neotropical Birds
A banana is an edible fruit – botanically a berry – produced by several kinds of large herbaceous flowering plants in the genus Musa. In some countries, bananas used for cooking may be called "plantains", distinguishing them from dessert bananas; the fruit is variable in size and firmness, but is elongated and curved, with soft flesh rich in starch covered with a rind, which may be green, red, purple, or brown when ripe. The fruits grow in clusters hanging from the top of the plant. All modern edible seedless bananas come from two wild species – Musa acuminata and Musa balbisiana; the scientific names of most cultivated bananas are Musa acuminata, Musa balbisiana, Musa × paradisiaca for the hybrid Musa acuminata × M. balbisiana, depending on their genomic constitution. The old scientific name for this hybrid, Musa sapientum, is no longer used. Musa species are native to tropical Indomalaya and Australia, are to have been first domesticated in Papua New Guinea, they are grown in 135 countries for their fruit, to a lesser extent to make fiber, banana wine, banana beer and as ornamental plants.
The world's largest producers of bananas in 2017 were India and China, which together accounted for 38% of total production. Worldwide, there is no sharp distinction between "bananas" and "plantains". In the Americas and Europe, "banana" refers to soft, dessert bananas those of the Cavendish group, which are the main exports from banana-growing countries. By contrast, Musa cultivars with firmer, starchier fruit are called "plantains". In other regions, such as Southeast Asia, many more kinds of banana are grown and eaten, so the binary distinction is not useful and is not made in local languages; the term "banana" is used as the common name for the plants that produce the fruit. This can extend to other members of the genus Musa, such as the scarlet banana, the pink banana, the Fe'i bananas, it can refer to members of the genus Ensete, such as the snow banana and the economically important false banana. Both genera are in Musaceae; the banana plant is the largest herbaceous flowering plant. All the above-ground parts of a banana plant grow from a structure called a "corm".
Plants are tall and sturdy, are mistaken for trees, but what appears to be a trunk is a "false stem" or pseudostem. Bananas grow in a wide variety of soils, as long as the soil is at least 60 cm deep, has good drainage and is not compacted; the leaves of banana plants are composed of a blade. The base of the petiole widens to form a sheath; the edges of the sheath meet. As new growth occurs in the centre of the pseudostem the edges are forced apart. Cultivated banana plants vary in height depending on growing conditions. Most are around 5 m tall, with a range from'Dwarf Cavendish' plants at around 3 m to'Gros Michel' at 7 m or more. Leaves may grow 2.7 metres long and 60 cm wide. They are torn by the wind, resulting in the familiar frond look; when a banana plant is mature, the corm stops producing new leaves and begins to form a flower spike or inflorescence. A stem develops which grows up inside the pseudostem, carrying the immature inflorescence until it emerges at the top; each pseudostem produces a single inflorescence known as the "banana heart".
After fruiting, the pseudostem dies, but offshoots will have developed from the base, so that the plant as a whole is perennial. In the plantation system of cultivation, only one of the offshoots will be allowed to develop in order to maintain spacing; the inflorescence contains many bracts between rows of flowers. The female flowers appear in rows further up the stem from the rows of male flowers; the ovary is inferior, meaning that the tiny petals and other flower parts appear at the tip of the ovary. The banana fruits develop from the banana heart, in a large hanging cluster, made up of tiers, with up to 20 fruit to a tier; the hanging cluster is known as a bunch, comprising 3–20 tiers, or commercially as a "banana stem", can weigh 30–50 kilograms. Individual banana fruits average 125 grams, of which 75% is water and 25% dry matter; the fruit has been described as a "leathery berry". There is a protective outer layer with numerous long, thin strings, which run lengthwise between the skin and the edible inner portion.
The inner part of the common yellow dessert variety can be split lengthwise into three sections that correspond to the inner portions of the three carpels by manually deforming the unopened fruit. In cultivated varieties, the seeds are diminished nearly to non-existence. Bananas are slightly radioactive, more so than most other fruits, because of their potassium content and the small amounts of the isotope potassium-40 found in occurring potassium; the banana equivalent dose of radiation is sometimes used in nuclear communication to compare radiation levels and exposures. The word banana is thought to be of West African origin from the Wolof word banaana, passed
The sombre hummingbird is the only species in the genus Aphantochroa. It is a species of hummingbird in the family Trochilidae, it is endemic to Brazil. Its natural habitats are subtropical or tropical moist lowland forest and degraded former forest
The rufous sabrewing is a species of hummingbird in the family Trochilidae. It is found in El Salvador and Mexico, its natural habitats are subtropical or tropical moist montane forest and degraded former forest. Image at ADW
Heliconia, derived from the Greek word Ἑλικώνιος, is a genus of flowering plants in the family Heliconiaceae. Most of the ca 194 known species are native to the tropical Americas, but a few are indigenous to certain islands of the western Pacific and Maluku. Many species of Heliconia are found in the tropical forests of these regions. Several species are cultivated as ornamentals, a few are naturalized in Florida and Thailand. Common names for the genus include lobster-claws, toucan peak, wild plantains or false bird-of-paradise; the last term refers to their close similarity to the bird-of-paradise flowers. Collectively, these plants are simply referred to as heliconias; these herbaceous plants range from 0.5 to nearly 4.5 meters tall depending on the species. The simple leaves of these plants are 15–300 cm, they are characteristically long, alternate, or growing opposite one another on non-woody petioles longer than the leaf forming large clumps with age. Their flowers are produced on long, erect or drooping panicles, consist of brightly colored waxy bracts, with small true flowers peeping out from the bracts.
The growth habit of heliconias is similar to Canna and bananas, to which they are related. The flowers can be hues of reds, oranges and greens, are subtended by brightly colored bracts. Floral shape limits pollination to a subset of the hummingbirds in the region; the leaves in different positions on the plant have a different absorption potential of sunlight for photosynthesis when exposed to different degrees of sunlight.droopy The flowers produce ample nectar that attracts pollinators, most prevalent of which are hummingbirds. Fruits are blue-purple when ripe and bird dispersed. Studies of post-dispersal seed survival showed; the highest amount of seed predation came from mammals. The Heliconia are a monophyletic genus in the family Heliconiaceae, but was included in the family Musaceae, which includes the bananas. However, the APG system of 1998, its successor, the APG II system of 2003, confirm the Heliconiaceae as distinct and places them in the order Zingiberales, in the commelinid clade of monocots.
Species accepted by Kew Botanic Gardens Most of the 194 known species are native to the tropical Americas, but a few are indigenous to certain islands of the western Pacific and Maluku. Many species of Heliconia are found in the tropical forests of these regions. Several species are cultivated as ornamentals, a few are naturalized in Florida and Thailand. Heliconias are an important food source for forest hummingbirds the hermits, some of which – such as the rufous-breasted hermit – use the plant for nesting; the Honduran white bat lives in tents it makes from heliconia leaves. Although Heliconia are exclusively pollinated by hummingbirds, some bat pollination has been found to occur. Heliconia solomonensis is pollinated by the macroglosine bat in the Solomon Islands. Heliconia solomonensis has green inflorescences and flowers that open at night, typical of bat pollinated plants; the macroglosine bat is the only known nocturnal pollinator of Heliconia solomonensis. Many bats use; the Honduran white bat, Ectohylla alba, utilizes five species of Heliconia to make diurnal tent-shaped roosts.
The bat cuts the side veins of the leaf extending from the midrib, causing the leaf to fold like a tent. This structure provides the bat with shelter from rain and predators. In addition, the stems of the Heliconia leaves are not strong enough to carry the weight of typical bat predators, so shaking of the leaf alerts roosting bats to presence of predators; the bats Artibeus anderseni and A. phaeotis form tents from the leaves of Heliconia in the same manner as the Honduran white bat. The neotropical disk-winged bat, Thyroptera tricolor, has suction disks on the wrists which allow it to cling to the smooth surfaces of the Heliconia leaves; this bat roosts head-up in the rolled young leaves of Heliconia plants. Heliconias provide shelter for a diverse range of insects within their young rolled leaves and water-filled floral bracts. Insects that inhabit the rolled leaves feed upon the inner surfaces of the leaf, such as beetles of the family Chrysomelidae. In bracts containing small amounts of water, fly larvae and beetles are the dominant inhabitants.
In bracts with greater quantities of water the typical inhabitants are mosquito larva. Insects living in the bracts feed on the bract tissue, nectar of the flower, flower parts, other insects, microorganisms, or detritus in the water contained in the bract. All species of Hispini beetles that use rolled leaves are obligate herbivores of plants of the order of Zingiberales, which includes Heliconia; these beetles live in and feed from the rolled leaf, the stems, the inflorescences, or the unfurled mature leaves of the Heliconia plant. In addition, these beetles deposit their eggs on the leaf surface, petioles of immature leaves, or in the bracts of the Heliconia. Furthermore, some wasp species such as Polistes erythrocephalus build their nest on the protected underside of large leaves. Hummingbirds are the main pollinators of heliconia flowers in many locations; the concurrent diversification of hummingbird-pollinated taxa in the order Zingiberales and the hummingbird family starting 18 million years ago supports the idea that these radiations have influenced one another through evolutionary time.
At La Selva Research Station in Costa Rica, specific species of Heliconia were found to have specific hummin