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Owl are birds from the order Strigiformes^[1] (/ˈstrɪdʒəfɔːrmiːz/), which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers adapted for silent flight. Exceptions include the diurnal northern hawk-owl and the gregarious burrowing owl.

Owls are divided into two families: the true (or typical) owl family, Strigidae, and the barn owl and bay owl family, Tytonidae.^[2] Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish. They are found in all regions of the Earth except the polar ice caps and some remote islands.

A group of owls is called a “parliament”.^[3]

Anatomy

Owls possess large, forward-facing eyes and ear-holes, a hawk-like beak, a flat face, and usually a conspicuous circle of feathers, a facial disc, around each eye. The feathers making up this disc can be adjusted to sharply focus sounds from varying distances onto the owls’ asymmetrically placed ear cavities. Most birds of prey have eyes on the sides of their heads, but the stereoscopic nature of the owl’s forward-facing eyes permits the greater sense of depth perception necessary for low-light hunting. Owls have binocular vision, but they must rotate their entire heads to change the focus of their view because, like most birds, their eyes are fixed in their sockets. Owls are farsighted and cannot clearly see anything nearer than a few centimetres of their eyes. Caught prey can be felt by owls with the use of filoplumes—hairlike feathers on the beak and feet that act as “feelers”. Their far vision, particularly in low light, is exceptionally good.

Owls can rotate their heads and necks as much as 270°. Owls have 14 neck vertebrae — humans have only seven — and their vertebral circulatory systems are adapted to allow them to rotate their heads without cutting off blood to the brain. Specifically, the foramina in their vertebrae through which the vertebral arteries pass are about ten times the diameter of the artery, instead of about the same size as the artery, as is the case in humans; the vertebral arteries enter the cervical vertebrae higher than in other birds, giving the vessels some slack, and the carotid arteries unite in a very large anastomosis or junction, the largest of any bird’s, preventing blood supply from being cut off while they rotate their necks. Other anastomoses between the carotid and vertebral arteries support this effect.^[4][5]

The smallest owl—weighing as little as 31 g (1+³⁄₃₂ oz) and measuring some 13.5 cm (5+¹⁄₄ in)—is the elf owl (Micrathene whitneyi).^[6] Around the same diminutive length, although slightly heavier, are the lesser known long-whiskered owlet (Xenoglaux loweryi) and Tamaulipas pygmy owl (Glaucidium sanchezi).^[6] The largest owls are two similarly sized eagle owls; the Eurasian eagle-owl (Bubo bubo) and Blakiston’s fish owl (Bubo blakistoni). The largest females of these species are 71 cm (28 in) long, have a 190 cm (75 in) wing span, and weigh 4.2 kg (9+¹⁄₄ lb).^{[6][7][8][9][10]}

Different species of owls produce different sounds; this distribution of calls aids owls in finding mates or announcing their presence to potential competitors, and also aids ornithologists and birders in locating these birds and distinguishing species. As noted above, their facial discs help owls to funnel the sound of prey to their ears. In many species, these discs are placed asymmetrically, for better directional location.

Owl plumage is generally cryptic, although several species have facial and head markings, including face masks, ear tufts, and brightly colored irises. These markings are generally more common in species inhabiting open habitats, and are thought to be used in signaling with other owls in low-light conditions.^[11]

Sexual dimorphism

Sexual dimorphism is a physical difference between males and females of a species. Female owls are typically larger than the males.^[12] The degree of size dimorphism varies across multiple populations and species, and is measured through various traits, such as wing span and body mass.^[12]

One theory suggests that selection has led males to be smaller because it allows them to be efficient foragers. The ability to obtain more food is advantageous during breeding season. In some species, female owls stay at their nest with their eggs while it is the responsibility of the male to bring back food to the nest.^[13] If food is scarce, the male first feeds himself before feeding the female.^[14] Small birds, which are agile, are an important source of food for owls. Male burrowing owls have been observed to have longer wing chords than females, despite being smaller than females.^[14] Furthermore, owls have been observed to be roughly the same size as their prey.^[14] This has also been observed in other predatory birds,^[13] which suggests that owls with smaller bodies and long wing chords have been selected for because of the increased agility and speed that allows them to catch their prey.^{[citation needed]}

Another popular theory suggests that females have not been selected to be smaller like male owls because of their sexual roles. In many species, female owls may not leave the nest. Therefore, females may have a larger mass to allow them to go for a longer period of time without starving. For example, one hypothesized sexual role is that larger females are more capable of dismembering prey and feeding it to their young, hence female owls are larger than their male counterparts.^[12]

A different theory suggests that the size difference between male and females is due to sexual selection: since large females can choose their mate and may violently reject a male’s sexual advances, smaller male owls that have the ability to escape unreceptive females are more likely to have been selected.^[14]

If the character is stable, there can be different optimums for both sexes. Selection operates on both sexes at the same time; therefore it is necessary to explain not only why one of the sexes is relatively bigger, but also why the other sex is smaller.^[15] If owls are still evolving toward smaller bodies and longer wing chords, according to V. Geodakyan’s Evolutionary Theory of Sex, males should be more advanced on these characters. Males are viewed as an evolutionary vanguard of a population, and sexual dimorphism on the character, as an evolutionary “distance” between the sexes. “Phylogenetic rule of sexual dimorphism” states that if there exists a sexual dimorphism on any character, then the evolution of this trait goes from the female form toward the male one.^[16]

Hunting adaptations

All owls are carnivorous birds of prey and live on diets of insects, small rodents and lagomorphs. Some owls are also specifically adapted to hunt fish. They are very adept in hunting in their respective environments. Since owls can be found in nearly all parts of the world and across a multitude of ecosystems, their hunting skills and characteristics vary slightly from species to species, though most characteristics are shared among all species.^[17]

Flight and feathers

External videos
Experiment! How Does An Owl Fly So Silently?, from BBC Earth

Most owls share an innate ability to fly almost silently and also more slowly in comparison to other birds of prey. Most owls live a mainly nocturnal lifestyle and being able to fly without making any noise gives them a strong advantage over prey alert to the slightest sound in the night. A silent, slow flight is not as necessary for diurnal and crepuscular owls given that prey can usually see an owl approaching. Owls’ feathers are generally larger than the average birds’ feathers, have fewer radiates, longer pennulum, and achieve smooth edges with different rachis structures.^[18] Serrated edges along the owl’s remiges bring the flapping of the wing down to a nearly silent mechanism. The serrations are more likely reducing aerodynamic disturbances, rather than simply reducing noise.^[19] The surface of the flight feathers is covered with a velvety structure that absorbs the sound of the wing moving. These unique structures reduce noise frequencies above 2 kHz,^[20] making the sound level emitted drop below the typical hearing spectrum of the owl’s usual prey^[20][21] and also within the owl’s own best hearing range.^[22][23] This optimizes the owl’s ability to silently fly to capture prey without the prey hearing the owl first as it flies, and to hear any noise the prey makes. It also allows the owl to monitor the sound output from its flight pattern.

The disadvantage of such feather adaptations for barn owls is that their feathers are not waterproof.^[24] The adaptations mean that barn owls do not use the uropygial gland, informally the “preen” or “oil” gland, as most birds do, to spread oils across their plumage through preening.^[25] This makes them highly vulnerable to heavy rain when they are unable to hunt.^[26] Historically, they would switch to hunting indoors in wet weather, using barns and other agricultural buildings, but the decline in the numbers of these structures in the 20th and 21st centuries has reduced such opportunities.^[24] The lack of waterproofing means that barn owls are also susceptible to drowning, in drinking troughs and other structures with smooth sides. The Barn Owl Trust provides advice on how this can be mitigated, by the installation of floats.^[27]

Vision

Eyesight is a particular characteristic of the owl that aids in nocturnal prey capture. Owls are part of a small group of birds that live nocturnally, but do not use echolocation to guide them in flight in low-light situations. Owls are known for their disproportionally large eyes in comparison to their skulls. An apparent consequence of the evolution of an absolutely large eye in a relatively small skull is that the eye of the owl has become tubular in shape. This shape is found in other so-called nocturnal eyes, such as the eyes of strepsirrhine primates and bathypelagic fishes.^[28] Since the eyes are fixed into these sclerotic tubes, they are unable to move the eyes in any direction.^[29] Instead of moving their eyes, owls swivel their heads to view their surroundings. Owls’ heads are capable of swiveling through an angle of roughly 270°, easily enabling them to see behind them without relocating the torso.^[29] This ability keeps bodily movement at a minimum, thus reduces the amount of sound the owl makes as it waits for its prey. Owls are regarded as having the most frontally placed eyes among all avian groups, which gives them some of the largest binocular fields of vision. Owls are farsighted and cannot focus on objects within a few centimetres of their eyes.^[28][30] These mechanisms are only able to function due to the large-sized retinal image.^[31] Thus, the primary nocturnal function in the vision of the owl is due to its large posterior nodal distance; retinal image brightness is only maximized to the owl within secondary neural functions.^[31] These attributes of the owl cause its nocturnal eyesight to be far superior to that of its average prey.^[31]

Hearing

Further information: Sound localization in owls

Owls exhibit specialized hearing functions and ear shapes that also aid in hunting. They are noted for asymmetrical ear placements on the skull in some genera. Owls can have either internal or external ears, both of which are asymmetrical. Asymmetry has not been reported to extend to the middle or internal ear of the owl. Asymmetrical ear placement on the skull allows the owl to pinpoint the location of its prey. This is especially true for strictly nocturnal species such as the barn owls Tyto or Tengmalm’s owl.^[29] With ears set at different places on its skull, an owl is able to determine the direction from which the sound is coming by the minute difference in time that it takes for the sound waves to penetrate the left and right ears.^[32] The owl turns its head until the sound reaches both ears at the same time, at which point it is directly facing the source of the sound. This time difference between ears is about 30 microseconds. Behind the ear openings are modified, dense feathers, densely packed to form a facial ruff, which creates an anterior-facing, concave wall that cups the sound into the ear structure.^[33] This facial ruff is poorly defined in some species, and prominent, nearly encircling the face, in other species. The facial disk also acts to direct sound into the ears, and a downward-facing, sharply triangular beak minimizes sound reflection away from the face. The shape of the facial disk is adjustable at will to focus sounds more effectively.^[29]

The prominences above a great horned owl’s head are commonly mistaken as its ears. This is not the case; they are merely feather tufts. The ears are on the sides of the head in the usual location (in two different locations as described above).

Talons

While the auditory and visual capabilities of the owl allow it to locate and pursue its prey, the talons and beak of the owl do the final work. The owl kills its prey using these talons to crush the skull and knead the body.^[29] The crushing power of an owl’s talons varies according to prey size and type, and by the size of the owl. The burrowing owl (Athene cunicularia), a small, partly insectivorous owl, has a release force of only 5 N. The larger barn owl (Tyto alba) needs a force of 30 N to release its prey, and one of the largest owls, the great horned owl (Bubo virginianus), needs a force over 130 N to release prey in its talons.^[34] An owl’s talons, like those of most birds of prey, can seem massive in comparison to the body size outside of flight. The Tasmanian masked owl has some of the proportionally longest talons of any bird of prey; they appear enormous in comparison to the body when fully extended to grasp prey.^[35] An owl’s claws are sharp and curved. The family Tytonidae has inner and central toes of about equal length, while the family Strigidae has an inner toe that is distinctly shorter than the central one.^[34] These different morphologies allow efficiency in capturing prey specific to the different environments they inhabit.

Beak

The beak of the owl is short, curved, and downward-facing, and typically hooked at the tip for gripping and tearing its prey. Once prey is captured, the scissor motion of the top and lower bill is used to tear the tissue and kill. The sharp lower edge of the upper bill works in coordination with the sharp upper edge of the lower bill to deliver this motion. The downward-facing beak allows the owl’s field of vision to be clear, as well as directing sound into the ears without deflecting sound waves away from the face.^[36]

Camouflage

The coloration of the owl’s plumage plays a key role in its ability to sit still and blend into the environment, making it nearly invisible to prey. Owls tend to mimic the coloration and sometimes the texture patterns of their surroundings, the barn owl being an exception. The snowy owl (Bubo scandiacus) appears nearly bleach-white in color with a few flecks of black, mimicking their snowy surroundings perfectly, while the speckled brown plumage of the tawny owl (Strix aluco) allows it to lie in wait among the deciduous woodland it prefers for its habitat. Likewise, the mottled wood owl (Strix ocellata) displays shades of brown, tan, and black, making the owl nearly invisible in the surrounding trees, especially from behind. Usually, the only tell-tale sign of a perched owl is its vocalizations or its vividly colored eyes.

Behavior

Most owls are nocturnal, actively hunting their prey in darkness. Several types of owls are crepuscular—active during the twilight hours of dawn and dusk; one example is the pygmy owl (Glaucidium). A few owls are active during the day, also; examples are the burrowing owl (Speotyto cunicularia) and the short-eared owl (Asio flammeus).

Much of the owls’ hunting strategy depends on stealth and surprise. Owls have at least two adaptations that aid them in achieving stealth. First, the dull coloration of their feathers can render them almost invisible under certain conditions. Secondly, serrated edges on the leading edge of owls’ remiges muffle an owl’s wing beats, allowing an owl’s flight to be practically silent. Some fish-eating owls, for which silence has no evolutionary advantage, lack this adaptation.

An owl’s sharp beak and powerful talons allow it to kill its prey before swallowing it whole (if it is not too big). Scientists studying the diets of owls are helped by their habit of regurgitating the indigestible parts of their prey (such as bones, scales, and fur) in the form of pellets. These “owl pellets” are plentiful and easy to interpret, and are often sold by companies to schools for dissection by students as a lesson in biology and ecology.^[37]

Breeding and reproduction

Owl eggs typically have a white color and an almost spherical shape, and range in number from a few to a dozen, depending on species and the particular season; for most, three or four is the more common number. In at least one species, female owls do not mate with the same male for a lifetime. Female burrowing owls commonly travel and find other mates, while the male stays in his territory and mates with other females.^[38]

Evolution and systematics

Recent phylogenetic studies place owls within the clade Telluraves, most closely related to the Accipitrimorphae and the Coraciimorphae,^[39][40] although the exact placement within Telluraves is disputed.^[41][42]

See below cladogram:

Telluraves

AccipitrimorphaeCathartiformes (New World vultures)Accipitriformes (hawks and relatives)Strigiformes (owls)CoraciimorphaeColiiformes (mouse birds)CavitavesLeptosomiformes (cuckoo roller)Trogoniformes (trogons and quetzals)PicocoraciaeBucerotiformes (hornbills and relatives)PicodynastornithesCoraciiformes (kingfishers and relatives)Piciformes (woodpeckers and relatives)AustralavesCariamiformes (seriemas)EufalconimorphaeFalconiformes (falcons)PsittacopasseraePsittaciformes (parrots)Passeriformes (passerines)

Cladogram of Telluraves relationships based on Braun & Kimball (2021)^[43]

Some 220 to 225 extant species of owls are known, subdivided into two families: 1. true owls or typical owls family (Strigidae) and 2. barn-owls family (Tytonidae). Some entirely extinct families have also been erected based on fossil remains; these differ much from modern owls in being less specialized or specialized in a very different way (such as the terrestrial Sophiornithidae). The Paleocene genera Berruornis and Ogygoptynx show that owls were already present as a distinct lineage some 60–57 million years ago (Mya), hence, possibly also some 5 million years earlier, at the extinction of the non-avian dinosaurs. This makes them one of the oldest known groups of non-Galloanserae landbirds. The supposed “Cretaceous owls” Bradycneme and Heptasteornis are apparently non-avialan maniraptors.^[44]

During the Paleogene, the Strigiformes radiated into ecological niches now mostly filled by other groups of birds. ^{[clarification needed]} The owls as known today, though, evolved their characteristic morphology and adaptations during that time, too. By the early Neogene, the other lineages had been displaced by other bird orders, leaving only barn owls and typical owls. The latter at that time was usually a fairly generic type of (probably earless) owl similar to today’s North American spotted owl or the European tawny owl; the diversity in size and ecology found in typical owls today developed only subsequently.

Around the Paleogene-Neogene boundary (some 25 Mya), barn owls were the dominant group of owls in southern Europe and adjacent Asia at least; the distribution of fossil and present-day owl lineages indicates that their decline is contemporary with the evolution of the different major lineages of true owls, which for the most part seems to have taken place in Eurasia. In the Americas, rather, an expansion of immigrant lineages of ancestral typical owls occurred.

The supposed fossil herons “Ardea” perplexa (Middle Miocene of Sansan, France) and “Ardea” lignitum (Late Pliocene of Germany) were more probably owls; the latter was apparently close to the modern genus Bubo. Judging from this, the Late Miocene remains from France described as “Ardea” aureliensis should also be restudied.^[45] The Messelasturidae, some of which were initially believed to be basal Strigiformes, are now generally accepted to be diurnal birds of prey showing some convergent evolution toward owls. The taxa often united under Strigogyps^[46] were formerly placed in part with the owls, specifically the Sophiornithidae; they appear to be Ameghinornithidae instead.^[47][48][49]

For fossil species and paleosubspecies of extant taxa, see the genus and species articles. For a full list of extant and recently extinct owls, see the article List of owl species.

Unresolved and basal forms (all fossil)

• Berruornis (Late Paleocene of France) basal? Sophornithidae?
• Strigiformes gen. et sp. indet. (Late Paleocene of Zhylga, Kazakhstan)^[50]
• Primoptynx (Early Eocene of Wyoming, U.S.)^[51]
• Palaeoglaux (Middle-Late Eocene of West-Central Europe) own family Palaeoglaucidae or Strigidae?
• Palaeobyas (Late Eocene/Early Oligocene of Quercy, France) Tytonidae? Sophiornithidae?^{[citation needed]}
• Palaeotyto (Late Eocene/Early Oligocene of Quercy, France) Tytonidae? Sophiornithidae?^{[citation needed]}
• Strigiformes gen. et spp. indet. (Early Oligocene of Wyoming, U.S.)^[45]
• Ypresiglaux (Early Eocene of Essex, United Kingdom and Virginia, U.S.)^[52]

Ogygoptyngidae

• Ogygoptynx (Middle/Late Paleocene of Colorado, U.S.)

Protostrigidae

• Eostrix (Early Eocene of United States, Europe, and Mongolia). E. gulottai is the smallest known fossil (or living) owl.^[53]
• Minerva (Middle – Late Eocene of western U.S.) formerly Protostrix, includes “Aquila” ferox, “Aquila” lydekkeri, and “Bubo” leptosteus
• Oligostrix (mid-Oligocene of Saxony, Germany)

Sophiornithidae

• Sophiornis

Tytonidae

• Genus Tyto – the barn owls, grass owls, and masked owls, stand up to 500 mm (20 in) tall; some 15 extant species and possibly one recently extinct
• Genus Phodilus – the bay owls, two to three extant species and possibly one recently extinct

Fossil genera

• Nocturnavis (Late Eocene/Early Oligocene) includes “Bubo” incertus
• Selenornis (Late Eocene/Early Oligocene) – includes “Asio” henrici
• Necrobyas (Late Eocene/Early Oligocene – Late Miocene) includes “Bubo” arvernensis and Paratyto
• Prosybris (Early Oligocene? – Early Miocene)

Placement unresolved

• Tytonidae gen. et sp. indet. “TMT 164” (Middle Miocene) – Prosybris?

Strigidae

• Genus Aegolius – the saw-whet owls, four species
• Genus Asio – the eared owls, eight species
• Genus Athene – two to four species (depending on whether the genera Speotyto and Heteroglaux are included or not)
• Genus Bubo – the horned owls, eagle-owls and fish-owls; paraphyletic with the genera Nyctea, Ketupa, and Scotopelia, some 25 species
• Genus Glaucidium – the pygmy owls, about 30–35 species
• Genus Gymnasio – the Puerto Rican owl
• Genus Gymnoglaux – the bare-legged owl or Cuban screech-owl
• Genus Lophostrix – the crested owl
• Genus Jubula – the maned owl
• Genus Megascops – the screech owls, some 20 species
• Genus Micrathene – the elf owl
• Genus Ninox – the Australasian hawk-owls or boobooks, some 20 species
• Genus Otus – the scops owls; probably paraphyletic, about 45 species
• Genus Pseudoscops – the Jamaican owl
• Genus Psiloscops – the flammulated owl
• Genus Ptilopsis – the white-faced owls, two species
• Genus Pulsatrix – the spectacled owls, three species
• Genus Strix – the earless owls, about 15 species, including four previously assigned to Ciccaba
• Genus Surnia – the northern hawk-owl
• Genus Taenioptynx – the collared owlet
• Genus Uroglaux – the Papuan hawk-owl
• Genus Xenoglaux – the long-whiskered owlet

Extinct genera

• Genus Grallistrix – the stilt-owls, four species; prehistoric
• Genus Ornimegalonyx – the Caribbean giant owls, one to two species; prehistoric

Fossil genera

• Mioglaux (Late Oligocene? – Early Miocene of West-Central Europe) – includes “Bubo” poirreiri
• Intutula (Early/Middle – ?Late Miocene of Central Europe) – includes “Strix/Ninox” brevis
• Alasio (Middle Miocene of Vieux-Collonges, France) – includes “Strix” collongensis
• Oraristrix – the Brea owl (Late Pleistocene)

Placement unresolved

• “Otus/Strix” wintershofensis: fossil (Early/Middle Miocene of Wintershof West, Germany) – may be close to extant genus Ninox^[45]
• “Strix” edwardsi – fossil (Middle/Late? Miocene)
• “Asio” pygmaeus – fossil (Early Pliocene of Odesa, Ukraine)
• Strigidae gen. et sp. indet. UMMP V31030 (Late Pliocene) – Strix/Bubo?
• the Ibizan owl, Strigidae gen. et sp. indet. – prehistoric^[54]

Symbolism and mythology

Among the Kikuyu of Kenya, it was believed that owls were harbingers of death. If one saw an owl or heard its hoot, someone was going to die. In general, owls are viewed as harbingers of bad luck, ill health, or death. The belief is widespread even today.^[55]

In Hinduism, an owl is the vahana (mount) of the goddess Lakshmi, especially in the eastern region of India.^[56] Owls are considered a symbol of wealth, prosperity, wisdom, good luck, and fortune. This is the reason why Owls are seen with Lakshmi, who is also the goddess of fortune, wealth, and prosperity. At the same time, owls are also associated with evil times in Hinduism. At times, Chamunda (fearsome form of Chandi) is depicted seated on an owl, her vahana (mount or vehicle). Hindus believe that owls are messengers of death.^{[57][better source needed]} In China, owls were traditionally considered to be omens of evil or misfortune. In Japan, owls are regarded as lucky,^[58] although in ancient times they were associated with death.^[59]

In Sumerian, Akkadian, and Babylonian culture, the owl was associated with Lilith.^[60]

The modern West generally associates owls with wisdom and vigilance. This link goes back at least as far as Ancient Greece, where Athens, noted for art and scholarship, and Athena, Athens’ patron goddess and the goddess of wisdom, had the owl as a symbol.^[61] Marija Gimbutas traces veneration of the owl as a goddess, among other birds, to the culture of Old Europe, long pre-dating Indo-European cultures.^[62]

In medieval Europe, the owl was often used with more negative symbolism. The bird was associated with darkness, uncleanliness, and mourning. The bird was linked to the bubonic plague. Owls were even used as anti-Semetic caricatures of Jews.^[63][64]

T. F. Thiselton-Dyer, in his 1883 Folk-lore of Shakespeare, says that

from the earliest period it has been considered a bird of ill-omen,” and Pliny tells us how, on one occasion, even Rome itself underwent a lustration, because one of them strayed into the Capitol. He represents it also as a funereal bird, a monster of the night, the very abomination of humankind. Virgil describes its death howl from the top of the temple by night, a circumstance introduced as a precursor of Dido‘s death. Ovid, too, constantly speaks of this bird’s presence as an evil omen; and indeed the same notions respecting it may be found among the writings of most of the ancient poets.^[65]

Native American cultures

People often allude to the reputation of owls as bearers of supernatural danger when they tell misbehaving children, “the owls will get you”,^[66] and in most Native American folklore, owls are a symbol of death.

According to the Apache and Seminole tribes, hearing owls hooting is considered the subject of numerous “bogeyman” stories told to warn children to remain indoors at night or not to cry too much, otherwise the owl may carry them away.^[67][68] In some tribal legends, owls are associated with spirits of the dead, and the bony circles around an owl’s eyes are said to comprise the fingernails of apparitional humans. Sometimes owls are said to carry messages from beyond the grave or deliver supernatural warnings to people who have broken tribal taboos.^[69]

The Aztecs and the Maya, along with other natives of Mesoamerica, considered the owl a symbol of death and destruction. In fact, the Aztec god of death, Mictlantecuhtli, was often depicted with owls.^[70] There is an old saying in Mexico that is still in use:^[71] Cuando el tecolote canta, el indio muere (“When the owl cries/sings, the Indian dies”). The Popol Vuh, a Mayan religious text, describes owls as messengers of Xibalba (the Mayan “Place of Fright”).^[72]

The belief that owls are messengers and harbingers of the dark powers is also found among the Hočągara (Winnebago) of Wisconsin.^[73] When in earlier days the Hočągara committed the sin of killing enemies while they were within the sanctuary of the chief’s lodge, an owl appeared and spoke to them in the voice of a human, saying, “From now on, the Hočągara will have no luck.” This marked the beginning of the decline of their tribe.^[74] An owl appeared to Glory of the Morning, the only female chief of the Hočąk nation, and uttered her name. Soon after, she died.^[75][76]

According to the culture of the Hopi, a Uto-Aztec tribe, taboos surround owls, which are associated with sorcery and other evils.^{[citation needed]}

The Ojibwe tribes, as well as their Aboriginal Canadian counterparts, used an owl as a symbol for both evil and death. In addition, they used owls as a symbol of very high status of spiritual leaders of their spirituality.^[77]

The Pawnee tribes viewed owls as the symbol of protection from any danger within their realms.^[77]

The Puebloan peoples associated owls with Skeleton Man, the god of death and the spirit of fertility.^[77]

The Yakama tribes use an owl as a totem, to guide where and how forests and natural resources are useful with management.^[77]

Rodent control

Encouraging natural predators to control rodent population is a natural form of pest control, along with excluding food sources for rodents. Placing a nest box for owls on a property can help control rodent populations (one family of hungry barn owls can consume more than 3,000 rodents in a nesting season) while maintaining the naturally balanced food chain.^[78]

Conservation issues

See also: List of Strigiformes by population

Almost all owls are listed in Appendix II of the international CITES treaty (the Convention on Illegal Trade in Endangered Species of Wild Fauna and Flora) with four species listed in Appendix I. Although owls have long been hunted, a 2008 news story from Malaysia indicates that the magnitude of owl poaching may be on the rise. In November 2008, TRAFFIC reported the seizure of 900 plucked and “oven-ready” owls in Peninsular Malaysia. Said Chris Shepherd, Senior Programme Officer for TRAFFIC’s Southeast Asia office, “This is the first time we know of where ‘ready-prepared’ owls have been seized in Malaysia, and it may mark the start of a new trend in wild meat from the region. We will be monitoring developments closely.” TRAFFIC commended the Department of Wildlife and National Parks in Malaysia for the raid that exposed the huge haul of owls. Included in the seizure were dead and plucked barn owls, spotted wood owls, crested serpent eagles, barred eagles, and brown wood owls, as well as 7,000 live lizards.^[81]

In addition to hunting, other threats to owl populations are habitat loss, pesticides, viruses, and vehicle collisions.^[82][83]

Parrot (Psittaciformes), also known as psittacines (/ˈsɪtəsaɪnz/),^[1][2] are birds with a strong curved beak, upright stance, and clawed feet.^[a] They are classified in four families that contain roughly 410 species in 101 genera, found mostly in tropical and subtropical regions. The four families are the Psittaculidae (Old World parrots), Psittacidae (African and New World parrots), Cacatuidae (cockatoos), and Strigopidae (New Zealand parrots). One-third of all parrot species are threatened by extinction, with a higher aggregate extinction risk (IUCN Red List Index) than any other comparable bird group.^[3] Parrots have a generally pantropical distribution with several species inhabiting temperate regions as well. The greatest diversity of parrots is in South America^[4] and Australasia.^[5]

Parrots—along with ravens, crows, jays, and magpies—are among the most intelligent birds, and the ability of some species to imitate human speech enhances their popularity as pets. They form the most variably sized bird order in terms of length; many are vividly coloured and some, multi-coloured. Most parrots exhibit little or no sexual dimorphism in the visual spectrum.

The most important components of most parrots’ diets are seeds, nuts, fruit, buds, and other plant material. A few species sometimes eat animals and carrion, while the lories and lorikeets are specialised for feeding on floral nectar and soft fruits. Almost all parrots nest in tree hollows (or nest boxes in captivity), and lay white eggs from which hatch altricial (helpless) young.

Trapping wild parrots for the pet trade, as well as hunting, habitat loss, and competition from invasive species, has diminished wild populations, with parrots being subjected to more exploitation than any other group of wild birds. As of 2021, about 50 million parrots (half of all parrots) live in captivity, with the vast majority of these living as pets in people’s homes.^[6] Measures taken to conserve the habitats of some high-profile charismatic species have also protected many of the less charismatic species living in the same ecosystems.

Parrots are the only creatures that display true tripedalism, using their necks and beaks as limbs with propulsive forces equal to or greater than those forces generated by the forelimbs of primates when climbing vertical surfaces. They can travel with cyclical tripedal gaits when climbing.^[7]

Taxonomy

Origins and evolution

Psittaciform diversity in South America and Australasia suggests that the order may have evolved in Gondwana, centred in Australasia.^[8] The scarcity of parrots in the fossil record, however, presents difficulties in confirming the hypothesis. There is currently a higher number of fossil remains from the northern hemisphere in the early Cenozoic.^[9] Molecular studies suggest that parrots evolved approximately 59 million years ago (Mya) (range 66–51 Mya) in Gondwana. The Neotropical Parrots are monophyletic, and the three major clades originated about 50 Mya (range 57–41 Mya).^[10]

A single 15 mm (0.6 in) fragment from a large lower bill (UCMP 143274), found in deposits from the Lance Creek Formation in Niobrara County, Wyoming, had been thought to be the oldest parrot fossil and is presumed to have originated from the Late Cretaceous period, which makes it about 70 million years old.^[11] However, other studies suggest that this fossil is not from a bird, but from a caenagnathid oviraptorosaur (a non-avian dinosaur with a birdlike beak), as several details of the fossil used to support its identity as a parrot are not actually exclusive to parrots, and it is dissimilar to the earliest-known unequivocal parrot fossils.^[12][13]

It is generally assumed that the Psittaciformes were present during the Cretaceous–Paleogene extinction event (K-Pg extinction), 66 mya. They were probably generalised arboreal birds, and did not have the specialised crushing bills of modern species.^[9][14] Genomic analysis provides strong evidence that parrots are the sister group of passerines, forming the clade Psittacopasserae, which is the sister group of the falcons.^[15]

The first uncontroversial parrot fossils date to tropical Eocene Europe around 50 mya. Initially, a neoavian named Mopsitta tanta, uncovered in Denmark’s Early Eocene Fur Formation and dated to 54 mya, was assigned to the Psittaciformes. However, the rather nondescript bone is not unequivocally psittaciform, and it may rather belong to the ibis genus Rhynchaeites, whose fossil legs were found in the same deposits.^[16]

Several fairly complete skeletons of parrot-like birds have been found in England and Germany.^[17] These are probably not transitional fossils between ancestral and modern parrots, but rather lineages that evolved parallel to true parrots and cockatoos:^[18]

• Psittacopes
• Serudaptus
• Halcyornithidae
  • Cyrilavis
  • Halcyornis
  • Pulchrapollia
  • Pseudasturides
• Vastanavidae
  • Vastanavis
• Quercypsittidae
  • Quercypsitta
• Messelasturidae^[19]
  • Messelastur
  • Tynskya

The earliest records of modern parrots date to around 23–20 mya.^[20] The fossil record—mainly from Europe—consists of bones clearly recognisable as belonging to anatomically modern parrots.^[21] The Southern Hemisphere contains no known parrot-like remains earlier than the Early Miocene around 20 mya.^[20]

Etymology

The name ‘Psittaciformes’ comes from the ancient Greek for parrot, ψιττακός (‘Psittacus’), whose origin is unclear. Ctesias (5th century BCE) recorded the name Psittacus after the Indian name for a bird, most likely a parakeet (now placed in the genus Psittacula). Pliny the Elder (23/24–79 CE) in his Natural History (book 10, chapter 58) noted that the Indians called the bird “siptaces”; however, no matching Indian name has been traced.^[22][23] Popinjay is an older term for parrots, first used in English in the 1500s.^[24]

Phylogeny

Molecular phylogenetic studies have shown that Psittaciformes form a monophyletic clade that is sister to the Passeriformes:^[25][26] The time calibrated phylogeny indicates that the Australaves diverged around 65 Ma (million years ago) and the Psittaciformes diverged from the Passeriformes around 62 Ma.^[26]

Australaves	Cariamiformes – seriemasFalconiformes – falconsPasseriformes – songbirdsPsittaciformes – parrots

Most taxonomists now divide Psittaciformes into four families: Strigopidae (New Zealand parrots), Cacatuidae (Cockatoos), Psittacidae (African and New World parrots) and Psittaculidae (Old World parrots).^[27] In 2012, Leo Joseph and collaborators proposed that the parrots should be divided into six families. The New Zealand parrots in the genus Nestor were placed in a separate family Nestoridae and the two basal genera in the family Psittaculidae (Psittrichas and Coracopsis) were placed in a separate family Psittrichasiidae.^[28] The two additional families have not been recognised by taxonomists involved in curating lists of world birds and instead only four families are recognised.^{[27][29][30][31]}

The following cladogram shows the phylogenetic relationships between the four families. The species numbers are taken from the list maintained by Frank Gill, Pamela Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC), now the International Ornithologists’ Union.^[27][32]

Psittaciformes	Strigopidae – New Zealand parrots (4 species)Cacatuidae – Cockatoos (22 species)Psittacidae – African and New World parrots (179 species)Psittaculidae – Old World parrots (203 species)

The Psittaciformes comprise three main lineages: Strigopoidea, Psittacoidea and Cacatuoidea.^[28] The Strigopoidea were considered part of the Psittacoidea, but the former is now placed at the base of the parrot tree next to the remaining members of the Psittacoidea, as well as all members of the Cacatuoidea.^[8][33][34] The Cacatuoidea are quite distinct, having a movable head crest, a different arrangement of the carotid arteries, a gall bladder, differences in the skull bones, and lack the Dyck texture feathers that—in the Psittacidae—scatter light to produce the vibrant colours of so many parrots. Colourful feathers with high levels of psittacofulvin resist the feather-degrading bacterium Bacillus licheniformis better than white ones.^[35] Lorikeets were previously regarded as a third family, Loriidae,^[36]: 45 but are now considered a tribe (Loriini) within the subfamily Loriinae, family Psittaculidae. The two other tribes in the subfamily are the closely related fig parrots (two genera in the tribe Cyclopsittini) and budgerigar (tribe Melopsittacini).^[8][33][34]

PsittaciformesStrigopoideaStrigopidaeCacatuoideaCacatuidaePsittacoideaPsittacidaeNeotropical parrotsPsittacinaePsittaculidaePsittrichasinaePsittrichasCoracopsisPsittaculinaeBroad-tailed parrotsFig parrotsBudgerigarLories and LorikeetsBolbopsittacusHanging parrotsLovebirdsPsittacella

Phylogenetic relations between parrots[8]

Systematics

Main article: List of parrots

The order Psittaciformes consists of four families containing roughly 410 species belonging to 101 genera.^[27][28]

Superfamily Strigopoidea: New Zealand parrots

• Family Strigopidae
  • Subamily Nestorinae: two genera with two living (kea and New Zealand kākā) and several extinct species of the New Zealand region
  • Subfamily Strigopinae: the flightless, critically endangered kākāpō of New Zealand

Superfamily Cacatuoidea: cockatoos

• Family Cacatuidae
  • Subfamily Nymphicinae: one genus with one species, the cockatiel.
  • Subfamily Calyptorhynchinae: the black cockatoos
  • Subfamily Cacatuinae
    • Tribe Microglossini: one genus with one species, the black palm cockatoo
    • Tribe Cacatuini: four genera of white, pink, and grey species

Superfamily Psittacoidea: true parrots

• Family Psittacidae
  • Subfamily Psittacinae: two African genera, Psittacus and Poicephalus
  • Subfamily Arinae
    • Tribe Arini: 18 genera
    • Tribe Androglossini: seven genera.
• Family Psittaculidae
  • Subfamily Psittrichasinae: two genera, Psittrichas (Pesquet’s parrot), Coracopsis
  • Subfamily Platycercinae
    • Tribe Pezoporini: ground parrots and allies
    • Tribe Platycercini: broad-tailed parrots
  • Subfamily Psittacellinae: one genus (Psittacella) with several species
  • Subfamily Loriinae
    • Tribe Loriini: lories and lorikeets
    • Tribe Melopsittacini: one genus with one species, the budgerigar
    • Tribe Cyclopsittini: fig parrots
  • Subfamily Agapornithinae: three genera
  • Subfamily Psittaculinae
    • Tribe Polytelini: three genera
    • Tribe Psittaculini: Asian psittacines
    • Tribe Micropsittini: pygmy parrots

Morphology

Skeletons

Kākāpō (critically endangered)

Paradise parrot (extinct)

Glaucous macaw (extinct)

Living species range in size from the buff-faced pygmy parrot, at under 10 g (0.4 oz) in weight and 8 cm (3.1 in) in length,^[36]: 149 to the hyacinth macaw, at 1 m (3.3 ft) in length,^[37] and the kākāpō, at 4.0 kg (8.8 lb) in weight.^[38] Among the superfamilies, the three extant Strigopoidea species are all large parrots, and the cockatoos tend to be large birds, as well. The Psittacoidea parrots are far more variable, ranging the full spectrum of sizes shown by the family.^[38]

The most obvious physical characteristic is the strong, curved, broad bill. The upper mandible is prominent, curves downward, and comes to a point. It is not fused to the skull, which allows it to move independently, and contributes to the tremendous biting pressure the birds are able to exert. A large macaw, for example, has a bite force of 35 kg/cm² (500 lb/sq in), close to that of a large dog.^[39] The lower mandible is shorter, with a sharp, upward-facing cutting edge, which moves against the flat part of the upper mandible in an anvil-like fashion. Touch receptors occur along the inner edges of the keratinised bill, which are collectively known as the “bill tip organ“, allowing for highly dexterous manipulations. Seed-eating parrots have a strong tongue (containing similar touch receptors to those in the bill tip organ), which helps to manipulate seeds or position nuts in the bill so that the mandibles can apply an appropriate cracking force. The head is large, with eyes positioned high and laterally in the skull, so the visual field of parrots is unlike any other birds. Without turning its head, a parrot can see from just below its bill tip, all above its head, and quite far behind its head. Parrots also have quite a wide frontal binocular field for a bird, although this is nowhere near as large as primate binocular visual fields.^[40] Unlike humans, the vision of parrots is also sensitive to ultraviolet light.^[41]

Parrots have strong zygodactyl feet (two toes facing forward and two back) with sharp, elongated claws, which are used for climbing and swinging. Most species are capable of using their feet to manipulate food and other objects with a high degree of dexterity, in a similar manner to a human using their hands. A study conducted with Australian parrots has demonstrated that they exhibit “handedness“, a distinct preference with regards to the foot used to pick up food, with adult parrots being almost exclusively “left-footed” or “right-footed”, and with the prevalence of each preference within the population varying by species.^[42]

Cockatoo species have a mobile crest of feathers on the top of their heads, which they can raise for display, and retract.^[43] No other parrots can do so, but the Pacific lorikeets in the genera Vini and Phigys can ruffle the feathers of the crown and nape, and the red-fan parrot (or hawk-headed parrot) has a prominent feather neck frill that it can raise and lower at will. The predominant colour of plumage in parrots is green, though most species have some red or another colour in small quantities. Cockatoos, however, are predominately black or white with some red, pink, or yellow.^[44]

Strong sexual dimorphism in plumage is not typical among parrots, with some notable exceptions, the most striking being the eclectus parrot.^{[36]: 202–207} However, it has been shown that some parrot species exhibit sexually dimorphic plumage in the ultraviolet spectrum, normally invisible to humans.^[45][46]

Distribution and habitat

See also: List of Psittaciformes by population

Parrots are found on all tropical and subtropical continents and regions including Australia and Oceania,^[5] South Asia, Southeast Asia, Central America, South America,^[4] and Africa.^[47] Some Caribbean and Pacific islands are home to endemic species.^[48] By far the greatest number of parrot species come from Australasia and South America.^[49] The lories and lorikeets range from Sulawesi and the Philippines in the north to Australia and across the Pacific as far as French Polynesia, with the greatest diversity being found in and around New Guinea.^[48] The subfamily Arinae encompasses all the neotropical parrots, including the amazons, macaws, and conures, and ranges from northern Mexico and the Bahamas to Tierra del Fuego in the southern tip of South America.^[50] The pygmy parrots, tribe Micropsittini, form a small genus restricted to New Guinea and the Solomon Islands.^[51] The superfamily Strigopoidea contains three living species of aberrant parrots from New Zealand.^[52] The broad-tailed parrots, subfamily Platycercinae, are restricted to Australia, New Zealand, and the Pacific islands as far eastwards as Fiji.^[53] The true parrot superfamily, Psittacoidea, includes a range of species from Australia and New Guinea to South Asia and Africa.^[48] The centre of cockatoo biodiversity is Australia and New Guinea, although some species reach the Solomon Islands (and one formerly occurred in New Caledonia),^[54] Wallacea and the Philippines.^[55]

Several parrots inhabit the cool, temperate regions of South America and New Zealand. Three species—the thick-billed parrot, the green parakeet, and the now-extinct Carolina parakeet—have lived as far north as the southern United States. Many parrots, especially monk parakeets, have been introduced to areas with temperate climates, and have established stable populations in parts of the United States (including New York City),^[56] the United Kingdom,^[57] Belgium,^[58] Spain,^[59][60] and Greece.^[61] These birds can be quite successful in introduced areas, such as the non-native population of red-crowned amazons in the U.S. which may rival that of their native Mexico.^[62] The only parrot to inhabit alpine climates is the kea, which is endemic to the Southern Alps mountain range on New Zealand’s South Island.^[63]

Few parrots are wholly sedentary or fully migratory. Most fall somewhere between the two extremes, making poorly understood regional movements, with some adopting an entirely nomadic lifestyle.^[64] Only three species are migratory – the orange-bellied, blue-winged and swift parrots.^[65]

Behaviour

Numerous challenges are found in studying wild parrots, as they are difficult to catch and once caught, they are difficult to mark. Most wild bird studies rely on banding or wing tagging, but parrots chew off such attachments.^[64] Parrots also tend to range widely, and consequently many gaps occur in knowledge of their behaviour. Some parrots have a strong, direct flight. Most species spend much of their time perched or climbing in tree canopies. They often use their bills for climbing by gripping or hooking on branches and other supports. Researchers at the New York Institute of Technology published findings that showed parrots used their beaks as a “third limb” to propel themselves.^[66] On the ground, parrots often walk with a rolling gait.^[40]

Diet

A yellow-tailed black cockatoo using its strong bill to search for grubs

The diet of parrots consists of seeds, fruit, nectar, pollen, buds, and sometimes arthropods and other animal prey. The most important of these for most true parrots and cockatoos are seeds; the large and powerful bill has evolved to open and consume tough seeds. All true parrots, except the Pesquet’s parrot, employ the same method to obtain the seed from the husk; the seed is held between the mandibles and the lower mandible crushes the husk, whereupon the seed is rotated in the bill and the remaining husk is removed.^[64] They may use their foot sometimes to hold large seeds in place. Parrots are granivores rather than seed dispersers, and in many cases where they are seen consuming fruit, they are only eating the fruit to get at the seed. As seeds often have poisons that protect them, parrots carefully remove seed coats and other chemically defended fruit parts prior to ingestion. Many species in the Americas, Africa, and Papua New Guinea consume clay, which releases minerals and absorbs toxic compounds from the gut.^[67]

Geographical range and body size predominantly explains the diet composition of Neotropical parrots rather than phylogeny.^[68]

Lories, lorikeets, hanging parrots, and swift parrots are primarily nectar and pollen consumers, and have tongues with brush tips to collect it, as well as some specialised gut adaptations. Many other species also consume nectar when it becomes available.^[69][70]

Some parrot species prey on animals, especially invertebrate larvae. Golden-winged parakeets prey on water snails,^[71] the New Zealand kea can, though uncommonly, hunt adult sheep,^[72] and the Antipodes parakeet, another New Zealand parrot, enters the burrows of nesting grey-backed storm petrels and kills the incubating adults.^[73] Some cockatoos and the New Zealand kākā excavate branches and wood to feed on grubs; the bulk of the yellow-tailed black cockatoo‘s diet is made up of insects.^[74]

Some extinct parrots had carnivorous diets. Pseudasturids were probably cuckoo– or puffbird-like insectivores, while messelasturids were raptor-like carnivores.^[19]

Breeding

With few exceptions, parrots are monogamous breeders who nest in cavities and hold no territories other than their nesting sites.^[64][75] The pair bonds of the parrots and cockatoos are strong and a pair remains close during the nonbreeding season, even if they join larger flocks. As with many birds, pair bond formation is preceded by courtship displays; these are relatively simple in the case of cockatoos. In Psittacidae parrots’ common breeding displays, usually undertaken by the male, include slow, deliberate steps known as a “parade” or “stately walk” and the “eye-blaze“, where the pupil of the eye constricts to reveal the edge of the iris.^[64] Allopreening is used by the pair to help maintain the bond. Cooperative breeding, where birds other than the breeding pair help raise the young and is common in some bird families, is extremely rare in parrots, and has only unambiguously been demonstrated in the El Oro parakeet and the golden parakeet (which may also exhibit polygamous, or group breeding, behaviour with multiple females contributing to the clutch).^[76]

Only the monk parakeet and five species of lovebirds build nests in trees,^[77] and three Australian and New Zealand ground parrots nest on the ground. All other parrots and cockatoos nest in cavities, either tree hollows or cavities dug into cliffs, banks, or the ground. The use of holes in cliffs is more common in the Americas. Many species use termite nests, possibly to reduce the conspicuousness of the nesting site or to create a favourable microclimate.^[78] In most cases, both parents participate in nest excavation. The length of the burrow varies with species, but is usually between 0.5 and 2 m (1.6 and 6.6 ft) in length. The nests of cockatoos are often lined with sticks, wood chips, and other plant material. In the larger species of parrots and cockatoos, the availability of nesting hollows may be limited, leading to intense competition for them both within the species and between species, as well as with other bird families. The intensity of this competition can limit breeding success in some cases.^[79][80] Hollows created artificially by arborists have proven successful in boosting breeding rates in these areas.^[81] Some species are colonial, with the burrowing parrot nesting in colonies up to 70,000 strong.^[82] Coloniality is not as common in parrots as might be expected, possibly because most species adopt old cavities rather than excavate their own.^[83]

The eggs of parrots are white. In most species, the female undertakes all the incubation, although incubation is shared in cockatoos, the blue lorikeet, and the vernal hanging parrot. The female remains in the nest for almost all of the incubation period and is fed both by the male and during short breaks. Incubation varies from 17 to 35 days, with larger species having longer incubation periods. The newly born young are altricial, either lacking feathers or with sparse white down. The young spend three weeks to four months in the nest, depending on species, and may receive parental care for several months thereafter.^[84]

As typical of K-selected species, the macaws and other larger parrot species have low reproductive rates. They require several years to reach maturity, produce one or very few young per year, and do not necessarily breed every year.^[85]: 125

Intelligence and learning

See also: Bird intelligence

Some grey parrots have shown an ability to associate words with their meanings and form simple sentences. Along with crows, ravens, and jays (family Corvidae), parrots are considered the most intelligent of birds. The brain-to-body size ratio of psittacines and corvines is comparable to that of higher primates.^[86] Instead of using the cerebral cortex like mammals, birds use the mediorostral HVC for cognition.^{[87][failed verification]} Not only have parrots demonstrated intelligence through scientific testing of their language-using ability, but also some species of parrots, such as the kea, are also highly skilled at using tools and solving puzzles.^[88]

Learning in early life is apparently important to all parrots, and much of that learning is social learning. Social interactions are often practised with siblings, and in several species, crèches are formed with several broods. Foraging behaviour is generally learnt from parents, and can be a very protracted affair. Generalists and specialists generally become independent of their parents much quicker than partly specialised species who may have to learn skills over long periods as various resources become seasonally available. Play forms a large part of learning in parrots; play can be solitary or social. Species may engage in play fights or wild flights to practice predator evasion. An absence of stimuli can delay the development of young birds, as demonstrated by a group of vasa parrots kept in tiny cages with domesticated chickens from the age of three months; at nine months, these birds still behaved in the same way as three-month-olds, but had adopted some chicken behaviour.^[64] In a similar fashion, captive birds in zoo collections or pets can, if deprived of stimuli, develop stereotyped and harmful behaviours like self-plucking. Aviculturists working with parrots have identified the need for environmental enrichment to keep parrots stimulated.^[89]

Sound imitation and speech

Main article: Talking bird

See also: Animal languageDuration: 44 seconds.0:44Subtitles available.CCVideo of an orange-winged amazon saying “hello” having been prompted by some humans

Many parrots can imitate human speech or other sounds. A study by scientist Irene Pepperberg suggested a high learning ability in a grey parrot named Alex. Alex was trained to use words to identify objects, describe them, count them, and even answer complex questions such as “How many red squares?” with over 80% accuracy.^[90] N’kisi, another grey parrot, has been shown to have a vocabulary of around a thousand words, and has displayed an ability to invent and use words in context in correct tenses.^[91]

Parrots do not have vocal cords, so sound is accomplished by expelling air across the mouth of the trachea in the organ called the syrinx. Different sounds are produced by changing the depth and shape of the trachea.^[92] Grey parrots are known for their superior ability to imitate sounds and human speech, which has made them popular pets since ancient times.^[93]

Although most parrot species are able to imitate, some of the amazon parrots are generally regarded as the next-best imitators and speakers of the parrot world. The question of why birds imitate remains open, but those that do often score very high on tests designed to measure problem-solving ability. Wild grey parrots have been observed imitating other birds.^[94]

Besides imitation, it is possible that parrots could be trained to use simple communication tools, e.g., to request food or a favourite activity by pushing a button.^[95]

Song

Parrots are unusual among birds due to their learned vocalizations, a trait they share with only hummingbirds and songbirds.^[96] The syrinx (vocal organ) of parrots, which aids in their ability to produce song, is located at the base of the trachea and consists of two complex syringeal muscles that allow for the production of sound vibrations, and a pair of lateral tympaniform membranes that control sound frequency.^[97] The position of the syrinx in birds allows for directed air flow into the interclavicular air sacs according to air sac pressure, which in turn creates a higher and louder tone in birds’ singing.^[96]

Cooperation

A 2011 study stated that some African grey parrots preferred to work alone, while others like to work together.^[98] With two parrots, they know the order of tasks or when they should do something together at once, but they have trouble exchanging roles. With three parrots, one parrot usually prefers to cooperate with one of the other two, but all of them are cooperating to solve the task.^[99]

Longevity

The heightened longevity of parrots appears to involve increased expression of several genomic features including genes employed in cell division, cell cycle regulation, RNA binding/processing, repair of DNA damage and oxidative stress response pathways.^[100]

Relationship with humans

Pets

Further information: Companion parrot

Parrots may not make good pets for most people because of their natural wild instincts such as screaming and chewing. Although parrots can be very affectionate and cute when immature, they often become aggressive when mature (partly due to mishandling and poor training) and may bite, causing serious injury.^[101] For this reason, parrot rescue groups estimate that most parrots are surrendered and rehomed through at least five homes before reaching their permanent destinations or before dying prematurely from unintentional or intentional neglect and abuse. The parrots’ ability to mimic human words and their bright colours and beauty prompt impulse buying from unsuspecting consumers. The domesticated budgerigar, a small parrot, is the most popular of all pet bird species.^[102] In 1992, the newspaper USA Today published that 11 million pet birds were in the United States alone,^[103] many of them parrots. Europeans kept birds matching the description of the rose-ringed parakeet (or called the ring-necked parrot), documented particularly in a first-century account by Pliny the Elder.^[104] As they have been prized for thousands of years for their beauty and ability to talk, they have also often been misunderstood. For example, author Wolfgang de Grahl says in his 1987 book The Grey Parrot that some importers had parrots drink only coffee while they were shipped by boat, believing that pure water was detrimental and that their actions would increase survival rates during shipping.^[105] Nowadays, it is commonly accepted that the caffeine in coffee is toxic to birds.^[106]

Pet parrots may be kept in a cage or aviary; though generally, tame parrots should be allowed out regularly on a stand or gym. Depending on locality, parrots may be either wild-caught or be captive-bred, though in most areas without native parrots, pet parrots are captive-bred. Parrot species that are commonly kept as pets include conures, macaws, amazon parrots, cockatoos, greys, lovebirds, cockatiels, budgerigars, caiques, parakeets, and Eclectus, Pionus, and Poicephalus species. Temperaments and personalities vary even within a species, just as with dog breeds. Grey parrots are thought to be excellent talkers, but not all grey parrots want to talk, though they have the capability to do so. Noise level, talking ability, cuddliness with people, and care needs can sometimes depend on how the bird is cared for and the attention he/she regularly receives.^[107]

Parrots invariably require an enormous amount of attention, care, and intellectual stimulation to thrive, akin to that required by a three-year-old child, which many people find themselves unable to provide in the long term.^[108] Parrots that are bred for pets may be hand-fed or otherwise accustomed to interacting with people from a young age to help ensure they become tame and trusting. However, even when hand fed, parrots revert to biting and aggression during hormonal surges and if mishandled or neglected.^[109] Parrots are not low-maintenance pets; they require feeding, grooming, veterinary care, training, and environmental enrichment through the provision of toys, exercise, and social interaction (with other parrots or humans) for good health.^[110]

Some large parrot species, including large cockatoos, amazons, and macaws, have very long lifespans, with 80 years being reported,^[111] and record ages of over 100.^[112] Small parrots, such as lovebirds, hanging parrots, and budgies, have shorter lifespans up to 15–20 years.^[113] Some parrot species can be quite loud, and many of the larger parrots can be destructive and require a very large cage, and a regular supply of new toys, branches, or other items to chew up.^[107] The intelligence of parrots means they are quick to learn tricks and other behaviours—both good and bad—that get them what they want, such as attention or treats.^[110]

The popularity, longevity, and intelligence of many of the larger kinds of pet parrots and their wild traits such as screaming, has led to many birds needing to be rehomed during the course of their long lifespans. A common problem is that large parrots that are cuddly and gentle as juveniles mature into intelligent, complex, often demanding adults who can outlive their owners, and can also become aggressive or even dangerous. Due to an increasing number of homeless parrots, they are being euthanised like dogs and cats, and parrot adoption centres and sanctuaries are becoming more common.^{[85]: 77–78} Parrots do not often do well in captivity, causing some parrots to go insane and develop repetitive behaviours, such as swaying and screaming, or they become riddled with intense fear. Feather destruction and self-mutilation, although not commonly seen in the wild, occur often in captivity.^[114][115]

Some owners have offered their pet parrots mobile apps for entertainment.^[116] Scientists Rébecca Kleinberger of Northeastern University and Ilyena Hirskyj-Douglas of the University of Glasgow performed a pilot study to tailor apps to parrots’ preferences. The birds tended to use rapid tongue movements to interact with screens, possibly mimicking movements used to manipulate seeds.^[116] To motivate parrots participating in the pilot study, researchers used treats such as peanut butter, yoghurt and pine nuts; one bird responded better to “cheering and praise”.^[116]

Trade

Main article: International parrot trade

The popularity of parrots as pets has led to a thriving—and often illegal—trade in the birds, and some species are now threatened with extinction. A combination of trapping of wild birds and damage to parrot habitats makes survival difficult or even impossible for some species of parrot. Importation of wild-caught parrots into the US and Europe is illegal after the Wild Bird Population Act was passed in 1992.^[119]

The scale of the problem can be seen in the Tony Silva case of 1996, in which a parrot expert and former director at Tenerife‘s Loro Parque (Europe’s largest parrot park) was jailed in the United States for 82 months and fined $100,000 for smuggling hyacinth macaws (such birds command a very high price.)^[120]

Different nations have different methods of handling internal and international trade. Australia has banned the export of its native birds since 1960.^[121] In July 2007, following years of campaigning by NGOs and outbreaks of avian flu, the European Union (EU) halted the importation of all wild birds with a permanent ban on their import.^[122] Prior to an earlier temporary ban started in late October 2005, the EU was importing about two million live birds a year, about 90% of the international market: hundreds of thousands of these were parrots.^[123] No national laws protect feral parrot populations in the U.S.^[124]

Mexico has a licensing system for capturing and selling native birds.^[125] According to a 2007 report, 65,000 to 78,500 parrots are captured annually, but the mortality rate before reaching a buyer is over 75%, meaning around 50,000 to 60,000 will die.^[126]

Culture

Parrots have featured in human writings, story, art, humor, religion, and music for thousands of years, such as Aesop’s fable “The parrot and the cat”,^[127] the mention “The parrot can speak, and yet is nothing more than a bird” in The Book of Rites of Ancient China,^[128] the Masnavi by Rumi of Persia in 1250 “The Merchant and the Parrot”.^[129] Recent books about parrots in human culture include Parrot Culture.^[130]

In ancient times and current, parrot feathers have been used in ceremonies and for decoration.^[131] They also have a long history as pets, stretching back thousands of years, and were often kept as a symbol of royalty or wealth.^[132]

Parrots are used as symbols of nations and nationalism. A parrot is found on the flag of Dominica and two parrots on their coat of arms.^[133] The St. Vincent parrot is the national bird of St. Vincent and the Grenadines, a Caribbean nation.^[134]

Sayings about parrots colour the modern English language. The verb “parrot” in the dictionary means “to repeat by rote”. Also clichés such as the British expression “sick as a parrot” are given; although this refers to extreme disappointment rather than illness, it may originate from the disease of psittacosis, which can be passed to humans.^[135][136] The first occurrence of a related expression is in Aphra Behn‘s 1681 play The False Count.^[137] Fans of Jimmy Buffett are known as parrotheads.^[138] Parrots feature in many media. Magazines are devoted to parrots as pets, and to the conservation of parrots.^[139] Fictional media include Monty Python‘s “Dead Parrot sketch“,^[140] Home Alone 3^[141] and Rio;^[142] and documentaries include The Wild Parrots of Telegraph Hill.^[143]

Parrots have been a food source to several groups. Australian settlers made parrot pies,^[144] while the Maori hunted kakapos for their meat and feathers.

Mythology

As early as the ancient Chinese Shang dynasty (c. 1600 BCE – 1045 BCE), jade artifacts are found crafted in the shape of parrots and were subjected to burning over wood along with other jade objects and livestock, likely as a part of ritual sacrifices known as ‘Liao’ sacrifices (燎祭), generating smoke offerings to the heavens, gods and ancestors. This ritual is believed to have been inherited from previous worship practices and continued into the Zhou dynasty. A jade parrot, among other artifacts, recovered from the tomb of Fu Hao at Yinxu provides significant evidence of this practice.^[145]

In Polynesian legend as current in the Marquesas Islands, the hero Laka/Aka is mentioned as having undertaken a long and dangerous voyage to Aotona in what are now the Cook Islands, to obtain the highly prized feathers of a red parrot as gifts for his son and daughter. On the voyage, 100 of his 140 rowers died of hunger on their way, but the survivors reached Aotona and captured enough parrots to fill 140 bags with their feathers.^[146][147]

Parrots have also been considered sacred. The Moche people of ancient Peru worshipped birds and often depicted parrots in their art.^[148] Parrots are popular in Buddhist scripture and many writings about them exist. For example, Amitābha once changed himself into a parrot to aid in converting people. Another old story tells how after a forest caught fire, the parrot was so concerned, it carried water to try to put out the flames. The ruler of heaven was so moved upon seeing the parrot’s act, he sent rain to put out the fire.^[149] In Chinese Buddhist iconography, a parrot is sometimes depicted hovering on the upper right side Guan Yin clasping a pearl or prayer beads in its beak.^[150]

In Hindu mythology, the parrot is the mount of the god of love, Kamadeva.^[151] The bird is also associated with the goddess Meenakshi and the poet-saint Andal.^[152]

Feral populations

Main article: Feral parrot

Escaped parrots of several species have become established in the wild outside their natural ranges and in some cases outside the natural range of parrots. Among the earliest instances were pet red shining-parrots from Fiji, which established a population on the islands of southern Tonga. These introductions were prehistoric and red-shining parrots were recorded in Tonga by Captain Cook in the 1770s.^[54] Escapees first began breeding in cities in California, Texas, and Florida in the 1950s (with unproven earlier claims dating to the 1920s in Texas and Florida).^[59] They have proved surprisingly hardy in adapting to conditions in Europe and North America. They sometimes even multiply to the point of becoming a nuisance or pest, and a threat to local ecosystems, and control measures have been used on some feral populations.^[153]

Feral parrot flocks can be formed after mass escapes of newly imported, wild-caught parrots from airports or quarantine facilities. Large groups of escapees have the protection of a flock and possess the skills to survive and breed in the wild.^[154] Some feral parakeets may have descended from escaped zoo birds. Escaped or released pets rarely contribute to establishing feral populations, as they usually result in only a few escapees, and most captive-born birds do not possess the necessary survival skills to find food or avoid predators and often do not survive long without human caretakers. However, in areas where there are existing feral parrot populations, escaped pets may sometimes successfully join these flocks.^[154][59] The most common years that feral parrots were released to non-native environments was from the 1890s to the 1940s, during the wild-caught parrot era.^[59] In the “parrot fever” panic of 1930, a city health commissioner urged everyone who owned a parrot to put them down, but some owners abandoned their parrots on the streets.^[155]

Threats and conservation

The principal threats of parrots are habitat loss and degradation, hunting, and, for certain species, the wild-bird trade.^[3] Parrots are persecuted because, in some areas, they are (or have been) hunted for food and feathers, and as agricultural pests. For a time, Argentina offered a bounty on monk parakeets for that reason, resulting in hundreds of thousands of birds being killed, though apparently this did not greatly affect the overall population.^[157]

Parrots, being cavity nesters, are vulnerable to the loss of nesting sites and to competition with introduced species for those sites. The loss of old trees is a particular problem in some areas, particularly in Australia, where suitable nesting trees must be centuries old. Many parrots occur only on islands and are vulnerable to introduced species such as rats and feral cat, as they lack the appropriate antipredator behaviours needed to deal with predators.^[158] Island species, such as the Puerto Rican amazon, which have small populations in restricted habitats, are also vulnerable to natural events, such as hurricanes.^[159] Due to deforestation, the Puerto Rican amazon is one of the world’s rarest birds despite conservation efforts.^[160]

One of the largest parrot conservation groups is the World Parrot Trust,^[161] an international organisation. The group gives assistance to worthwhile projects, as well as producing a magazine (PsittaScene)^[162] and raising funds through donations and memberships, often from pet parrot owners. On a smaller scale, local parrot clubs raise money to donate to a conservation cause. Zoo and wildlife centres usually provide public education, to change habits that cause damage to wild populations. Conservation measures to conserve the habitats of some of the high-profile charismatic parrot species has also protected many of the less charismatic species living in the ecosystem.^[163]: 12 A popular attraction that many zoos employ is a feeding station for lories and lorikeets, where visitors feed them with cups of liquid food. This is usually done in association with educational signs and lectures.^[164] Birdwatching-based ecotourism can be beneficial to economies.^[165]

Several projects aimed specifically at parrot conservation have met with success. Translocation of vulnerable kākāpō, followed by intensive management and supplementary feeding, has increased the population from 50 individuals to 123 in 2010^[166] and 247 in 2024.^[167] In New Caledonia, the Ouvea parakeet was threatened by trapping for the pet trade and loss of habitat. Community-based conservation, which eliminated the threat of poaching, has allowed the population to increase from around 600 birds in 1993 to over 2,000 birds in 2009.^[168]

As of 2009, the IUCN recognises 19 species of parrot as extinct since 1500 (the date used to denote modern extinctions).^[169] This does not include species like the New Caledonian lorikeet, which has not been officially seen for 100 years, yet is still listed as critically endangered.^[170]

Trade, export, and import of all wild-caught parrots is regulated and only permitted under special licensed circumstances in countries party to the Convention on the International Trade in Endangered Species (CITES) which came into force in 1975 to regulate the international trade of all endangered, wild-caught animal and plant species. In 1975, 24 parrot species were included in Appendix I, thus prohibiting commercial international trade in these birds. Since that initial listing, continuing threats from international trade led it to add an additional 32 parrot varieties to Appendix I.^[171] All other parrot species, aside from the rosy-faced lovebird, budgerigar, cockatiel and rose-ringed parakeet (which are not included in the appendices) are protected on Appendix II of CITES.^[172][173] In addition, individual countries may have laws to regulate trade in certain species; for example, the EU has banned parrot trade,^[123] whereas Mexico has a licensing system for capturing parrots.^[125]

World Parrot Day

Every year on 31 May, World Parrot Day is celebrated.^[174]