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56-451: Sonation is the sound produced by birds, using mechanisms other than the syrinx . The term sonate is described as the deliberate production of sounds, not from the throat, but rather from structures such as the bill, wings, tail, feet and body feathers, or by the use of tools. Examples are the tonal sound produced by the tail-feathers of the Anna's hummingbird Calypte anna , the drumming of

112-425: A duller bill. The subspecies differ in size, in the pattern of wattles on the head and in the glossiness of the plumage. A 2020 study found that the subspecies G. religiosa miotera likely represents a distinct species and was likely driven to extinction in the wild in the late 2010s due unsustainable collecting for the wildlife trade . The paper recommends rescuing the last genetically pure captive individuals for

168-405: A gap that produces the fluttering sound. Syrinx (biology) Unlike the larynx in mammals, the syrinx is located where the trachea forks into the lungs. Thus, lateralization is possible, with muscles on the left and right branch modulating vibrations independently so that some songbirds can produce more than one sound at a time. Some species of birds, such as New World vultures , lack

224-413: A lab setting, vocal pressures must have been central to the morphological shift. Though these experiments do not account for the role of the syrinx in more metabolically challenging behaviors, such as flight, Reide et al. put forth a compelling theory about the selection for the syrinx in response to increased vocal efficiency. This theory involves vocal tract length and the dynamics of airflow. While both

280-416: A large bulla located on the left side of the trachea, and the tracheosyringeal rings that line the trachea are thicker in male mallards than in females. Within the trachea there is a structure called the pessulus that divides the trachea in half where the two bronchus branch out. The pessulus is ossified, and lined with tympaniform membranes that influence the sound production depending on its thickness when

336-419: A larger frequency range or longer or louder calls than an alligator-like larynx, which would have potentially increased fitness. While the evidence is limited, selection for non-acoustic characteristics, such as structural support and respiratory function, may have contributed to the evolution of a syrinx-like structure at the tracheobronchial juncture. Due to airway bifurcation, the tracheobronchial juncture

392-407: A median dorsoventral structure, the pessulus, may be developed to varying extents. The pessulus is bony in passerines and provides attachment to membranes, anteriorly to the semilunar membranes. The membrane that forms part of the first three bronchial rings is responsible for vibrating and producing the sound in most passerines. These membranes may also be attached to the pessulus. In some species like

448-539: A nest in a hole in a tree. The usual clutch is two or three eggs . There is no sexual dimorphism in these birds, which results in a limited possibility of choosing the sex to work with for mating. The hill mynas are popular cage birds, renowned for their ability to imitate speech. The widely distributed common hill myna is the one most frequently seen in aviculture . Demand outstrips captive breeding capacity, so they are rarely found in pet stores and usually purchased directly from breeders or importers who can certify

504-419: A repertoire of three to 13 such call types, which may be shared with some near neighbours of the same sex, being learned when young. Dialects change rapidly with distance, such that birds living more than 15 km apart have no call-types in common with one another. Unlike some other birds, such as the greater racket-tailed drongo ( Dicrurus paradiseus ), the common hill myna does not imitate other birds in

560-406: A selective advantage for crown birds, but the causes for this shift remain unknown. To complicate matters, the syrinx falls into an unusual category of functional evolution: arising from ancestors with a larynx-based sound source, the syrinx contains significant functional overlap with the structure it replaced. In fact, there is no evidence that an original, simplified syrinx could produce calls with

616-557: A simplified airway conducted by Kingsley et al. (2018), fluctuations in flow patterns led to localized wall shear stress, with the highest stress during exhalation at the tracheobronchial juncture. Localized stress may have provided selective pressure for an airway support located at the tracheobronchial juncture to maintain airway patency. Understanding whether these forces would have favored the evolution of soft tissue or cartilage requires further experimentation. Continuous breathing alone, however, would not have provided enough pressure for

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672-452: A syrinx and communicate through throaty hisses. Birds do have a larynx, but unlike in mammals, it does not vocalize. The position of the syrinx, structure and musculature varies widely across bird groups. In some groups the syrinx covers the lower end of the trachea and the upper parts of the bronchi in which case the syrinx is said to be tracheobronchial, the most frequent form and the one found in all songbirds. The syrinx may be restricted to

728-408: A tube where the lowest resonant frequency of a vibrating object (i.e. the syrinx) is four times longer than the length of the tube. A shorter tube would be less efficient; a longer tube would cause wave-form skewing. In most mammalian species and their therapsid ancestors, tracheal length was not sufficient to facilitate a boost in vocal efficiency. With bolstered vocal efficiency due to longer necks,

784-466: Is significant given that sexing birds is difficult at younger stages. Birds that exhibit sexual dimorphism in the syrinx can present itself at around 10 days in Pekin ducks ( Anas platyrhynchos domestica ) . Male ducks have a large tracheal bulla (bulla syringealis) , whereas females have a smaller sized bulla. There are multiple key differences that distinguishes a male's syrinx from a female's. Males have

840-401: Is the avian equivalent of arthropod stridulation . Adult male red-billed streamertail hummingbirds ( Trochilus polytmus ) have long tail streamers, but these do not produce their distinctive whirring flight sound. Evidence points to the wings instead – the whirring is synchronised with the wingbeats and video footage shows primary feather eight (P8) bending with each downstroke, creating

896-539: The Enggano hill myna ( Gracula enganensis ) and the Tenggara hill myna ( Gracula venerata ) have all been classified as subspecies. This is a stocky jet-black myna , with bright orange-yellow patches of naked skin and fleshy wattles on the side of its head and nape. At about 29 cm length, it is somewhat larger than the common myna ( Acridotheres tristis ). It is overall green-glossed black plumage , purple-tinged on

952-531: The Otididae include foot-stamping in their mating displays. Studies have revealed at least four sonations employed by two manakin genera Manacus and Pipra  – wing-against-wing claps carried out above the back, wing-against-body claps, wing-into-air flicks and wing-against-tail feathers. Video footage of male club-winged manakins, Machaeropterus deliciosus , shows them producing sustained harmonics derived from vibrating secondary wing feathers. This mechanism

1008-560: The hill myna or myna bird , is the myna most commonly sighted in aviculture , where it is often simply referred to by the latter two names. It is a member of the starling family (Sturnidae), resident in hill regions of South Asia and Southeast Asia . The Sri Lanka hill myna , a former subspecies of G. religiosa , is now generally accepted as a separate species G. ptilogenys . The Enggano hill myna ( G. enganensis ) and Nias hill myna ( G. robusta ) are also widely accepted as specifically distinct, and many authors favor treating

1064-588: The southern hill myna ( G. indica ) from the Nilgiris and elsewhere in the Western Ghats of India as a separate species. The common hill myna is a popular talking bird . Its specific name religiosa may allude to the practice of teaching mynas to repeat prayers. The common hill myna was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae under

1120-543: The Cenozoic, these structures have not been recovered from Mesozoic archosaurs. This might be a product of weak mineralization in the bronchi and trachea of Mesozoic archosaurs, a condition which would inhibit preservation potential . Thus, a shift towards a mineralized structure may have been preceded by many key avian adaptations, including respiratory shifts, increases in metabolic rates, and feather ornamentation. The archosaurian shift from larynx to syrinx must have conferred

1176-582: The Philippines, the species was uplisted to CITES Appendix II . The Andaman and Nicobar Islands subspecies G. r. andamanensis and (if valid) G. r. halibrecta , described as "exceedingly common" in 1874, qualified as Near Threatened in 1991. The former is not at all common anymore in the Nicobar Islands and the latter—if distinct—has a very limited range. Elsewhere, such as on the Philippines and in Laos ,

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1232-464: The air runs past the pessulus, causing vibrations. The membranes in males are thick and nontransparent, but the females have thinner, sheer membranes. The nature of the sounds produced by males and females are different due to these differences in the syrinx. Females have a louder call because the space inside their bulla is not lined with a lot of fat or connective tissue, and the thinner tympaniform membrane takes less effort to vibrate. This decreases

1288-504: The attachment of the first muscles to the trachea to clear the airway for respiratory function. Therefore, the two pairs of extrinsic muscles present in the ancestral syrinx were likely selected to ensure that the airway did not collapse during non-vocal respiration. Further fossil data and taxonomical comparisons will be necessary to determine whether structural modifications of the syrinx unrelated to sound, such as respiratory support during continuous breathing or in flight, were exapted in

1344-604: The birds are traded legally. This species is widely distributed and locally common, and if adult stocks are safeguarded, it is able to multiply quickly. On a worldwide scale, the IUCN thus considers the common hill myna a Species of Least Concern . But in the 1990s, nearly 20,000 wild-caught birds, mostly adults and juveniles, were brought into trade each year. In the central part of its range, G. r. intermedia populations have declined markedly, especially in Thailand , which supplied much of

1400-604: The bronchi as in some non-passerines, notably the owls , cuckoos and nightjars . The syrinx may also be restricted to the trachea and this is found in a very small number of bird groups that are sometimes known as tracheophonae, a subset of the suboscine passeriformes that include Furnariidae (ovenbirds), Dendrocolaptidae (woodcreepers), Formicariidae (ground antbirds), Thamnophilidae (typical antbirds), Rhinocryptidae (tapaculos), and Conopophagidae (gnateaters). The trachea are covered in partly ossified rings known as tracheal rings. Tracheal rings tend to be complete, while

1456-478: The bronchi in crocodiles and humans, for example, diverge at different angles. Additionally, syrinx musculature was necessarily selected for maintaining respiratory function. Because sound is produced through the interaction of airflow and the self-oscillation of membranes within the trachea, a mechanism is necessary to abduct structures from the airway to allow for non-vocal respiration. Because of this, vibratory tissue precursors must have, at most, briefly predated

1512-409: The bronchial rings are C-shaped and the unossified part has smooth muscles running along them. The trachea are usual circular or oval in cross section in most birds but are flattened in ibises. The trachea is simple and tubular in ducks. The last few tracheal rings and the first few bronchial rings may fuse to form what is called the tympanic box. At the base of the trachea and at the joint of the bronchi

1568-474: The common hill myna, they extend from the eye to the nape, where they join, while the Sri Lanka hill myna has a single wattle across the nape and extending a bit towards the eyes. In the southern hill myna, the wattles are separate and curve towards the top of the head. The Nias and Enggano hill mynas differ in details of the facial wattles, and size, particularly that of the bill. Sexes are similar; juveniles have

1624-518: The current binomial name Gracula religiosa . The type location is the Indonesian island of Java . The genus name is from Latin graculus , an unknown bird sometimes identified as the western jackdaw . The specific epithet religiosa is from Latin religiosus meaning "sacred". Seven subspecies are recognised: The southern hill myna ( Gracula indica ), the Nias hill myna ( Gracula robusta ),

1680-467: The decline has been more localized. It is also becoming increasingly rare in the regions of northeastern India due to capture of fledged birds for the illegal pet trade . In the Garo Hills region, however, the locals make artificial nests of a split- bamboo framework covered with grass, and put them up in accessible positions in tall trees in a forest clearing or at the edge of a small village to entice

1736-479: The development of a vocal organ. Additionally, further research on tetrapod tracheas is necessary to understand potential constraints in the evolution of unique airway morphologies. While a need for structural support may have given rise to an organ at the tracheobronchial juncture, selection for vocal performance likely played a role in syrinx evolution. Riede et al. (2019) argue that because birds with deactivated syringeal muscles can breathe without difficulty within

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1792-658: The development of the novel syrinx. Mammals also respire through continuous breathing, yet they did not evolve the novel structure. Additional structural components must therefore be considered in syrinx evolution. Body size, relative neck length, and larynx position relative to the hyoid apparatus (i.e. the bones that suspend the tongue and larynx) are all known to have changed across Dinosauria evolution. Coupled with respiratory shifts, these characteristics may have favored syrinx evolution in birds. Distinct airway geometries in Mammalia and Archosauria may have also impacted syrinx evolution:

1848-415: The evolution of a simple syrinx may be tied to specific combinations of vocal fold morphology and body size. Before the origin of Aves and during the late Jurassic period, theropod-lineage dinosaurs underwent stature miniaturization and rapid diversification. It is possible that during these changes, certain co mbinations of body-size dependent vocal tract length and sound frequencies favored the evolution of

1904-477: The evolution of avian ancestors. The current fossil record does not provide definitive evidence for whether the function of the larynx was lost before the syrinx was gained. The fossil record does, however, provide clues for the evolutionary timeline of some syringeal elements. For example, increased mineralization at the tracheobronchial juncture is likely a late-arising feature in avian evolution. Despite new discoveries of preserved avian tracheobronchial rings from

1960-505: The force absorbed from the air moving through the syrinx, making a louder, higher pitched sound. On the other hand, males have a lot of fat and connective tissue in their bulla, which absorbs much more power from the moving air. This coupled with their thicker membranes leads to less vibrations and a duller, lower pitched sound. Common hill myna Gracula indica (but see text) The common hill myna ( Gracula religiosa ), sometimes spelled "mynah" and formerly simply known as

2016-529: The fossil record infrequently, making it difficult to determine when the shift in vocal organs occurred. An intact specimen from the late Cretaceous, however, highlights the fossilization potential of the ancestral structure and may indicate that the syrinx is a late-arising feature in avian evolution. There is uncertainty about the relationship between the larynx and syrinx during this morphological shift, but there are two predominant evolutionary possibilities: regimes unrelated to sound production could have led to

2072-414: The head and neck. Its large, white wing patches are obvious in flight, but mostly covered when the bird is sitting. The bill and strong legs are bright yellow, and there are yellow wattles on the nape and under the eye. These differ conspicuously in shape from the naked eye-patch of the common myna and bank myna ( A. ginginianus ), and more subtly vary between the different hill mynas from South Asia : in

2128-405: The hill-myna, Gracula religiosa , there is wide gap between the second and third bronchial semirings where large muscles are attached, allowing the inner diameter to be varied widely. Other muscles are also involved in syringeal control, these can be intrinsic or extrinsic depending on whether they are within the syrinx or attached externally. The extrinsic muscles include the sternotrachealis from

2184-408: The inertance (i.e. the “sluggishness” of air) and the easier it is to produce sound. Inertance must be considered alongside frequency—when a tube is lengthened beyond a quarter wavelength, standing waves interfere with sound production. Thus, acoustic theory predicts that to maximize energy transfer, birds must develop an appropriate length-frequency combination that produces inertance at the input of

2240-409: The larynx and the syrinx produce sound through the interaction of airflow and self-oscillating valves, the syrinx is located deeper in the respiratory tract than the larynx. This is a critical distinction between the structures, as the length of the air column above and below a sound source affects the way energy is conveyed from airflow to oscillating tissue. The longer and narrower the tube, the greater

2296-412: The loss in vocal function of the larynx. A new structure, the syrinx, then arose after selection for acoustic function. Conversely, the larynx could have retained some vocal capabilities, though at a diminished capacity. The syrinx then evolved to supplement sound production, which would have been followed by the loss of the larynx as a sound source. The former scenario would have led to a “silent” period in

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2352-666: The lower Himalayas , terai and foothills up to 2,000 m ASL . Its range continues east through Southeast Asia northeastwards to southern China , and via Thailand southeastwards across northern Indonesia to Palawan in the Philippines . It is virtually extinct in Bangladesh due to habitat destruction and overexploitation for the pet trade . A feral population on Christmas Island has likewise disappeared. Introduced populations exist in Saint Helena , Puerto Rico and perhaps in

2408-459: The mainland United States and possibly elsewhere; feral birds require at least a warm subtropical climate to persist. This myna is almost entirely arboreal, moving in large, noisy groups of half a dozen or so, in tree-tops at the edge of the forest. It hops sideways along the branch, unlike the characteristic jaunty walk of other mynas. Like most starlings, the hill myna is fairly omnivorous , eating fruit , nectar and insects . They build

2464-450: The mynas to breed there. The villagers are thus able to extract the young at the proper time for easy hand-rearing, making common hill myna farming a profitable, small-scale cottage industry . It helps to preserve the environment , because the breeding birds are not removed from the population, while habitat destruction is curtailed because the mynas will desert areas of extensive logging and prefer more natural forest to plantations . As

2520-400: The novel syrinx. Diversification in theropod stature may explain why birds alone capitalized on the efficiency of the novel structure. Importantly, birds generally have longer necks than mammals. This distinction is due to the unidirectional flow of the avian respiratory system, which increases efficiency of gas exchange. Efficiency permits more “dead space” within the avian trachea, allowing

2576-529: The purpose of captive breeding . The International Ornithological Congress tentatively recognises it as a subspecies. The common hill myna is often detected by its loud, shrill, descending whistles followed by other calls. It is most vocal at dawn and dusk, when it is found in small groups in forest clearings high in the canopy. Both sexes can produce an extraordinarily wide range of loud calls – whistles, wails, screeches, and gurgles, sometimes melodious and often very human-like in quality. Each individual has

2632-464: The specific acoustic advantage of the ancestral syrinx remains speculative, it is evident from modern avian diversification that sexual selection often drives vocal evolution. Sexual dimorphism leads to different syrinxes in birds, and the degree of differences varies. Some species do not present differences between sexes while others, like the mallard ( Anas platyrhynchos ) , have distinctly different syrinxes between males and females. This difference

2688-454: The sternum. Within the avian stem lineage, the transition from a larynx-based sound source to a tracheobronchial syrinx occurred within Dinosauria, at or before the origin of Aves about 66-68 million years ago. The earliest fossilized record of syringeal remains is from a single specimen of Vegavis iaai from the same epoch. Before this discovery, syringeal components were thought to enter

2744-484: The syrinx may have been retained in Aves by sexual selective forces. Acoustic communication is essential for courtship, territorial defense, and long-range communication, all of which greatly impact an organism's fitness. For example, polygynous birds with leklike mating systems have evolved to use louder sounds and a wider range of frequencies during displays; wood warblers with higher trill performance have higher fitness. While

2800-520: The tail-feathers of the African snipe and common snipe , bill-clattering by storks or the deliberate territorial tapping practised by woodpeckers and certain members of the parrot family, such as palm cockatoos which drum on hollow trees using broken-off sticks. The clapper lark's ( Mirafra apiata ) display flight includes a steep climb with wing rattling. Barn owls produce a clicking snap to show annoyance or fear. Bustards, floricans and korhaans of

2856-457: The thriving Western market. Its neighbor countries, from where exports were often limited due to political or military reasons, nevertheless supplied a burgeoning domestic demand, and demand in the entire region continues to be very high. In 1992, Thailand had the common hill myna put on CITES Appendix III , to safeguard its stocks against collapsing. In 1997, at the request of the Netherlands and

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2912-425: The trachea to lengthen without a subsequent decrease in tracheal diameter. With a longer trachea, the avian vocal system shifted to a range in which an overlap between fundamental frequency and first tracheal resonance was possible. Without the critical tracheal length, mammals were unable to achieve an ideal length-frequency tracheal combination. At this point in avian evolution, it may have become advantageous to move

2968-548: The trachea. In songbirds, this is achieved by matching fundamental frequency with the first vocal tract resonance. Using physical and computational models, Riede et al. discovered that because of the dynamics between inertance and tracheal length, a structure in the syringeal position can be significantly more efficient than a structure in the laryngeal position. Efficiency, however, is influenced significantly by non-linear interactions of trachea length, phonation threshold pressure, and frequency. Riede et al. therefore conclude that

3024-539: The vocal structure upstream to the syringeal position, near the tracheobronchial juncture. Selection for long necks, while highly variable, is often driven by beneficial feeding adaptations. Specifically, long necks facilitate underwater predation, evident in the extant genera Cygnus (swans) and Cormorant (shags). Longer necks likely predisposed Aves for syrinx evolution. Because of the correlation between neck length and tracheal length, birds are considered to have an “acoustically long trachea.” Technically, this refers to

3080-567: The wild, although it is a widely held misconception that they do. On the other hand, in captivity, they are among the most renowned mimics, the only bird, perhaps, on par with the grey parrot ( Psittacus erithacus ). They can learn to reproduce many everyday sounds, particularly the human voice, and even whistled tunes, with astonishing accuracy and clarity. This myna is a resident breeder from Kumaon division in India (80° E longitude ) east through Nepal , Sikkim , Bhutan and Arunachal Pradesh ,

3136-471: Was present at the origin of multiple lungs in tetrapods. In bird-lineage archosaurs with bifurcated airways, the evolution of an increased metabolic rate and continuous breathing exposed airway walls to altered amounts of wall shear stress , a measure of friction between a fluid and a vessel wall. In continuous breathers, such as birds and mammals, the trachea is exposed to fluctuations of wall shear stress during inspiration and expiration. In simulations with

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