Carrion crow

The carrion crow (Corvus corone) is a passerine bird of the family Corvidae and the genus Corvus which is native to western Europe and eastern Asia.

Taxonomy and systematics

The carrion crow was one of the many species originally described by Linnaeus in his 18th century work Systema Naturae and it still bears its original name of Corvus corone. The binomial name is derived from the Latin Corvus, "Raven", and Greek korone/κορωνη, "crow".

The subspecies of the hooded crow has been split off as a separate species, and there is some discussion whether the Eastern carrion crow (C. c. orientalis) is distinct enough to warrant specific status; the two taxa are well separated, and it has been proposed they could have evolved independently in the wetter, maritime regions at the opposite ends of the Eurasian landmass.

Description

The plumage of carrion crow is black with a green or purple sheen, much greener than the gloss of the rook. The bill, legs and feet are also black. It can be distinguished from the common raven by its size (48–52 cm or 18 to 21 inches in length as compared to an average of 63 centimetres (25 inches) for ravens) and from the hooded crow by its black plumage, but there is frequent confusion between it and the rook. The beak of the crow is stouter and in consequence looks shorter, and whereas in the adult rook the nostrils are bare, those of the crow are covered at all ages with bristle-like feathers.

Earth

Earth /ˈɜːrθ/ (also the world, in Greek: Γαῖα Gaia, or in Latin: Terra) is the third planet from the Sun, the densest planet in the Solar System, the largest of the Solar System's four terrestrial planets, and the only astronomical object known to harbor life.

According to evidence from radiometric dating and other sources, Earth was formed about 4.54 billion years ago. Earth gravitationally interacts with other objects in space, especially the Sun and the Moon. During one orbit around the Sun, Earth rotates about its own axis 366.26 times, creating 365.26 solar days or one sidereal year. Earth's axis of rotation is tilted 23.4° away from the perpendicular of its orbital plane, producing seasonal variations on the planet's surface with a period of one tropical year (365.24 solar days). The Moon is Earth's only permanent natural satellite. Its gravitational interaction with Earth causes ocean tides, stabilizes the orientation of Earth's rotational axis, and gradually slows Earth's rotational rate.

Carrion

Carrion (from the Latin "caro", meaning "meat") refers to the dead and decaying flesh of an animal.

Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include vultures, hawks, eagles,hyenas,Virginia opossum,Tasmanian devils,coyotes,Komodo dragons, and burying beetles. Many invertebrates such as the burying beetles, as well as maggots of calliphorid flies and flesh-flies also eat carrion, playing an important role in recycling nitrogen and carbon in animal remains.

Carrion begins to decay the moment of the animal's death, and it will increasingly attract insects and breed bacteria. Not long after the animal has died, its body will begin to exude a foul odor caused by the presence of bacteria and the emission of cadaverine and putrescine.

Some plants and fungi smell like decomposing carrion and attract insects that aid in reproduction. Plants that exhibit this behavior are known as carrion flowers. Stinkhorn mushrooms are examples of fungi with this characteristic.

Corvus (genus)

Corvus is a widely distributed genus of birds in the family Corvidae. Ranging in size from the relatively small pigeon-sized jackdaws (Eurasian and Daurian) to the common raven of the Holarctic region and thick-billed raven of the highlands of Ethiopia, the 40 or so members of this genus occur on all temperate continents except South America, and several islands. In Europe, the word "crow" is used to refer to the carrion crow or the hooded crow, while in North America, it is used for the American crow, fish crow, or the northwestern crow.

The crow genus makes up a third of the species in the family Corvidae. The members appear to have evolved in Asia from the corvid stock, which had evolved in Australia. The collective name for a group of crows is a 'flock' or a 'murder'.

Recent research has found some crow species capable of not only tool use, but also tool construction. Crows are now considered to be among the world's most intelligent animals with an encephalization quotient equal to that of many non-human primates.

Omen

An omen (also called portent or presage) is a phenomenon that is believed to foretell the future, often signifying the advent of change. People in the ancient times believed that omens lie with a divine message from their gods.

These omens include natural phenomena for example an eclipse, freak births of animals and humans and behavior of the sacrificial lamb on its way to the slaughter. They had specialists, the diviners, to interpret these omens. They would also use an artificial method, for example, a clay model of a sheep liver, to communicate with their gods in times of crisis. They would expect a binary answer, either yes or no answer, favorable or unfavorable. They did these to predict what would happen in the future and to take action to avoid disaster.

Though the word "omen" is usually devoid of reference to the change's nature, hence being possibly either "good" or "bad," the term is more often used in a foreboding sense, as with the word "ominous". The origin of the word is unknown, although it may be connected with the Latin word audire, meaning "to hear."