Owl in the context of "Facial disc"

The true owls or typical owls (family Strigidae) are one of the two generally accepted families of owls, the other being the barn owls and bay owls (Tytonidae). This large family comprises 230 living or recently extinct species in 24 genera. The Strigidae owls have a cosmopolitan distribution and are found on every continent except Antarctica.

The bird family Tytonidae, which includes the barn owls Tyto and the bay owls Phodilus, is one of the two families of owls, the other being the true owls or typical owls, Strigidae. Tytonidae are medium to large owls with large heads and characteristic heart-shaped faces. They have long, strong legs with powerful talons. Tytonidae also differ from the Strigidae in structural details relating in particular to the sternum and feet.

The family is wide-ranging, although they are not very tolerant of severe winter cold, so are absent from northern areas of Europe, Asia, and North America; they are also absent from driest desert regions. They live in a wide range of habitats from semi-deserts to forests, and from temperate latitudes to the tropics. Within these habitats, they live near agricultural areas with high amounts of human activity. The majority of the 20 living species of barn owls are poorly known. Some, like the red owl, have barely been seen or studied since their discovery, in contrast to the western barn owl Tyto alba, which is one of the best-known owl species in the world. However, some subspecies of the western barn owl possibly deserve to be separate species, but are very poorly known.

Nocturnality is a behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is nocturnal, with diurnal meaning the opposite.

Nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight. Some animals, such as ferrets, have eyes that can adapt to both low-level and bright day levels of illumination (see metaturnal). Others, such as bushbabies and (some) bats, can function only at night. Many nocturnal creatures including tarsiers and some owls have large eyes in comparison with their body size to compensate for the lower light levels at night. More specifically, they have been found to have a larger cornea relative to their eye size than diurnal creatures to increase their visual sensitivity: in the low-light conditions. Nocturnality helps wasps, such as Apoica flavissima, avoid hunting in intense sunlight.

The Star of Ishtar or Star of Inanna is a Mesopotamian symbol of the ancient Sumerian goddess Inanna and her East Semitic counterpart Ishtar. The owl was also one of Ishtar's primary symbols. Ishtar is mostly associated with the planet Venus, which is also known as the morning star.

Tyto is a genus of owls in the family Tytonidae. Depending on the species and the locality, common names include barn owl, common barn owl, grass owl, sooty owl, masked owl, field owl or simply owl. It is the most widely distributed genus of owls in the world and one of the most widespread of all genera of birds, living almost everywhere except for polar and desert regions, Asia north of the Himalayas, some Indonesian islands and some Pacific Islands.

The genus comprises three widespread continental species and many island species including the extinct island species. The widespread species comprise: western barn owl of Europe, western Asia and Africa, the eastern barn owl of Southeast Asia and Australasia, and the American barn owl of the Americas. However, some taxonomic authorities classify barn owls differently, and unify all continental barn owls in to one species. Further research is needed clarify the taxonomies.

The red owl (Tyto soumagnei) is an owl in the barn owl family Tytonidae. It is also known as the Madagascar red owl, Madagascar grass-owl, Soumagne's owl or lesser grass-owl. It is a rare resident of Madagascar that was virtually unknown from its discovery in 1876 to its rediscovery by researchers from the World Wide Fund for Nature in 1993. It is currently listed as vulnerable because of habitat loss, but recent studies have determined it may have a wider range than first believed, though further research in distribution and ecology is required. It has possibly been overlooked because of its close resemblance to the closely related barn owl.

The red owl resembles the cosmopolitan barn owl but is smaller (27–30 cm) and has rich orange plumage with small black spots. It is known to live in humid evergreen forest and dry deciduous forest in the east of the island, being found in primary forest and in disturbed secondary forest (possibly even human altered open areas). It feeds on native small-mammals like tenrecs (Tenrecidae) and tufted-tailed rats (as opposed to the barn owl, which feeds on introduced species). It nests and roosts in tree cavities and along cliffs with dense vegetation.

Flight feathers (Pennae volatus) are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (/ˈrɛmɪdʒiːz/), singular remex (/ˈriːmɛks/), while those on the tail are called rectrices (/ˈrɛktrɪsiːz/ or /rɛkˈtraɪsiːz/), singular rectrix (/ˈrɛktrɪks/). The primary function of the flight feathers is to aid in the generation of both thrust and lift, thereby enabling flight. The flight feathers of some birds perform additional functions, generally associated with territorial displays, courtship rituals or feeding methods. In some species, these feathers have developed into long showy plumes used in visual courtship displays, while in others they create a sound during display flights. Tiny serrations on the leading edge of their remiges help owls to fly silently (and therefore hunt more successfully), while the extra-stiff rectrices of woodpeckers help them to brace against tree trunks as they hammer on them. Even flightless birds still retain flight feathers, though sometimes in radically modified forms.

The remiges are divided into primary and secondary feathers based on their position along the wing. There are typically 11 primaries attached to the manus (six attached to the metacarpus and five to the phalanges), but the outermost primary, called the remicle, is often rudimentary or absent; certain birds, notably the flamingos, grebes, and storks, have seven primaries attached to the metacarpus and 12 in all. Secondary feathers are attached to the ulna. The fifth secondary remex (numbered inwards from the carpal joint) was formerly thought to be absent in some species, but the modern view of this diastataxy is that there is a gap between the fourth and fifth secondaries. Tertiary feathers growing upon the adjoining portion of the brachium are not considered true remiges.

A hypercarnivore is an animal that has a diet that is more than 70% meat, either via active predation or by scavenging. The remaining non-meat diet may consist of non-animal foods such as fungi, fruits or other plant material. Some extant examples of hypercarnivorous animals include crocodilians, owls, shrikes, eagles, vultures, felids, some wild canids, polar bear, odontocetid cetaceans (toothed whales), snakes, spiders, scorpions, mantises, marlins, groupers, piranhas and most sharks. Every species in the family Felidae, including the domesticated cat, is a hypercarnivore in its natural state. Additionally, this term is also used in paleobiology to describe taxa of animals which have an increased slicing component of their dentition relative to the grinding component. In domestic settings, e.g. cats may have a diet derived from only plant and synthetic sources using modern processing methods. Feeding farmed animals such as alligators and crocodiles mostly or fully plant-based feed is sometimes done to save costs or as an environmentally friendly alternative. Hypercarnivores are not necessarily apex predators. For example, salmon are exclusively carnivorous, yet they are prey at all stages of life for a variety of organisms.

Many prehistoric mammals of the clade Carnivoramorpha (Carnivora and Miacoidea without Creodonta), along with the early order Creodonta, and some mammals of the even earlier order Cimolesta, were hypercarnivores. The earliest carnivorous mammal is considered to be Cimolestes, which existed during the Late Cretaceous and early Paleogene periods in North America about 66 million years ago. Many theropod dinosaurs such as Tyrannosaurus rex that existed during the late Cretaceous, although not mammals, were obligate carnivores.

Telluraves, also known as land birds or core landbirds is a recently defined clade of birds defined by their arboreality. Based on most recent genetic studies, the clade unites a variety of bird groups, including the australavians (passerines, parrots, seriemas, and falcons) as well as the afroavians (including the Accipitrimorphae – eagles, hawks, buzzards, vultures etc. – owls and woodpeckers, among others). This grouping was defined in the PhyloCode by George Sangster and colleagues in 2022 as "the least inclusive crown clade containing Accipiter nisus and Passer domesticus". They appear to be the sister group of the Phaethoquornithes.

Based on phylogenetic relationships among lineages of the Afroaves and the Australaves, it has been suggested that the last common ancestor of all Telluraves may have been an apex predator, and possibly also a bird of prey. Other researchers are skeptical of this assessment, citing the herbivorous cariamiform Strigogyps as evidence to the contrary.

The burrowing owl (Athene cunicularia), also called the shoco, is a small, long-legged, primarily terrestrial—though not flightless—species of owl native to the open landscapes of North and South America. They are typically found in grasslands, rangelands, agricultural areas, deserts, or any other open, dry area with low vegetation. They nest and roost in burrows, and, despite their common name, do not often construct these dwellings themselves, rather repurposing disused burrows or tunnels previously excavated and inhabited by other species, such as American badgers (Taxidea taxus), foxes (Vulpes sp.), ground squirrels or prairie dogs (Cynomys spp.), among others.

Unlike most owls, burrowing owls are often active during the day, although they tend to avoid the heat of midday. But, similar to many other species of owls, they are mostly crepuscular hunters, as they can utilize their night vision and attuned hearing to maximum potential during sunrise and sunset. Having evolved to live on open grasslands and prairie habitat (as well as badlands, chaparral and desert ecosystems), as opposed to dense forest, the burrowing owl has developed longer legs than other owls, a trait which enables it to sprint when pursuing its prey, not dissimilarly to the greater roadrunner, as well as providing momentum when taking flight; however, burrowing owls typically only become airborne for short bursts, such as when fleeing threats, and typically do not fly very high off of the ground.

The barn owls, owls in the genus Tyto, are the most widely distributed genus of owls in the world. They are medium-sized owls with large heads and characteristic heart-shaped faces. They have long, strong legs with powerful talons. The term may be used to describe:

• The whole family Tytonidae, though this also includes the bay owls in the genus Phodilus
  • Tyto, the largest genus of birds in Tytonidae, and particularly these species in that genus:
    • Three species that are sometimes considered to be a single species known as barn owl or common barn owl:
      • Western barn owl Tyto alba, from Europe, Africa, and the Middle East
      • American barn owl Tyto furcata, from the Americas
      • Eastern barn owl Tyto javanica, from southeast Asia and Australasia
    • Andaman masked owl Tyto deroepstorffi endemic to the southern Andaman Islands
    • New Caledonian barn owl Tyto letocarti, extinct, from the island of New Caledonia in Melanesia

The American (North and South America) horned owls and the Old World eagle-owls make up the genus Bubo, at least as traditionally described. The genus name Bubo is Latin for owl.

This genus contains 10 species that are found in many parts of the world. Some of the largest living Strigiformes are in Bubo. Traditionally, only owls with ear-tufts were included in this genus, but that is no longer the case.

The trogons and quetzals are birds in the order Trogoniformes /troʊˈɡɒnɪfɔːrmiːz/ which contains only one family, the Trogonidae. The family Trogonidae contains 49 species in seven genera. The fossil record of the trogons dates back 49 million years to the Early Eocene. They might constitute a member of the basal radiation of the order Coraciiformes and order Passeriformes or be closely related to mousebirds and owls. The word trogon is Greek for "nibbling" and refers to the fact that these birds gnaw holes in trees to make their nests.

Trogons are residents of tropical forests worldwide. The greatest diversity is in the Neotropics, where four genera, containing 34 species, occur. The genus Apaloderma contains the three African species. The genera Harpactes and Apalharpactes, containing twelve species, are found in southeast Asia.