Bird song - AbsoluteAstronomy.com

Bird vocalization includes both bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology

Ornithology

Ornithology is a branch of zoology that concerns the study of birds. Several aspects of ornithology differ from related disciplines, due partly to the high visibility and the aesthetic appeal of birds...

and birding, (relatively complex) songs are distinguished by function from (relatively simple) calls.

Definition

The distinction between songs and calls is based upon complexity, length, and context. Songs are longer and more complex and are associated with courtship and mating, while calls tend to serve such functions as alarms or keeping members of a flock

Herd

Herd refers to a social grouping of certain animals of the same species, either wild or domestic, and also to the form of collective animal behavior associated with this or as a verb, to herd, to its control by another species such as humans or dogs.The term herd is generally applied to mammals,...

in contact. Other authorities such as Howell and Webb (1995) make the distinction based on function, so that short vocalizations such as those of pigeons and even non-vocal sounds such as the drumming of woodpecker

Woodpecker

Woodpeckers are near passerine birds of the order Piciformes. They are one subfamily in the family Picidae, which also includes the piculets and wrynecks. They are found worldwide and include about 180 species....

s and the "winnowing" of snipe

Snipe

A snipe is any of about 25 wading bird species in three genera in the family Scolopacidae. They are characterized by a very long, slender bill and crypsis plumage. The Gallinago snipes have a nearly worldwide distribution, the Lymnocryptes Jack Snipe is restricted to Asia and Europe and the...

s' wings in display flight are considered songs. Still others require song to have syllabic diversity and temporal regularity akin to the repetitive and transformative patterns which define music

Music

Music is an art form whose medium is sound and silence. Its common elements are pitch , rhythm , dynamics, and the sonic qualities of timbre and texture...

. It is generally agreed upon in birding and ornithology which sounds are songs and which are calls, and a good field guide will differentiate between the two.

Bird song is best developed in the order

Order (biology)

In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

Passeriformes

Passerine

A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...

. Most song is emitted by male rather than female birds. Song is usually delivered from prominent perches although some species may sing when flying. Some groups are nearly voiceless, producing only percussive and rhythm

Rhythm

Rhythm may be generally defined as a "movement marked by the regulated succession of strong and weak elements, or of opposite or different conditions." This general meaning of regular recurrence or pattern in time may be applied to a wide variety of cyclical natural phenomena having a periodicity or...

ic sounds, such as the stork

Stork

Storks are large, long-legged, long-necked wading birds with long, stout bills. They belong to the family Ciconiidae. They are the only family in the biological order Ciconiiformes, which was once much larger and held a number of families....

s, which clatter their bills. In some manakins (Pipridae), the males have evolved several mechanisms for mechanical sound production, including mechanisms for stridulation

Stridulation

Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fishes, snakes and spiders...

not unlike those found in some insects.

The production of sounds by mechanical means as opposed to the use of the syrinx

Syrinx (biology)

Syrinx is the name for the vocal organ of birds. Located at the base of a bird's trachea, it produces sounds without the vocal cords of mammals. The sound is produced by vibrations of some or all of the membrana tympaniformis and the pessulus caused by air flowing through the syrinx...

has been termed variously instrumental music by Charles Darwin

Charles Darwin

Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...

, mechanical sounds and more recently sonation
Sonation
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...

. The term sonate has been defined as the act of producing non-vocal sounds that are intentionally modulated communicative signals, produced using non-syringeal structures such as the bill, wings, tail, feet and body feathers.

Anatomy

The avian vocal organ is called the syrinx

Syrinx (biology)

; it is a bony structure at the bottom of the trachea

Vertebrate trachea

In tetrapod anatomy the trachea, or windpipe, is a tube that connects the pharynx or larynx to the lungs, allowing the passage of air. It is lined with pseudostratified ciliated columnar epithelium cells with goblet cells that produce mucus...

(unlike the larynx

Larynx

The larynx , commonly called the voice box, is an organ in the neck of amphibians, reptiles and mammals involved in breathing, sound production, and protecting the trachea against food aspiration. It manipulates pitch and volume...

at the top of the mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

ian trachea). The syrinx and sometimes a surrounding air sac resonate to sound waves that are made by membranes past which the bird forces air. The bird controls the pitch by changing the tension on the membranes and controls both pitch and volume by changing the force of exhalation. It can control the two sides of the trachea independently, which is how some species can produce two notes at once.

Function

Scientists hypothesize that bird song has evolved through sexual selection

Sexual selection

Sexual selection, a concept introduced by Charles Darwin in his 1859 book On the Origin of Species, is a significant element of his theory of natural selection...

, and experiments suggest that the quality of bird song may be a good indicator of fitness. Experiments also suggest that parasites and diseases may directly affect song characteristics such as song rate, which thereby act as reliable indicators of health. The song repertoire also appears to indicate fitness in some species. The ability of male birds to hold and advertise territories using song also demonstrates their fitness.

Communication through bird calls can be between individuals of the same species or even across species. Birds communicate alarm through vocalizations and movements that are specific to the threat, and bird alarms can be understood by other animal species, including other birds, in order to identify and protect against the specific threat.
Mobbing calls are used to recruit individuals in an area where an owl or other predator may be present. These calls are characterized by wide frequency spectra, sharp onset and termination, and repetitiveness which are common across species and are believed to be helpful to other potential "mobbers" by being easy to locate. The alarm calls of most species, on the other hand, are characteristically high-pitched making the caller difficult to locate.

Individual birds may be sensitive enough to identify each other through their calls. Many birds that nest in colonies can locate their chicks using their calls. Calls are sometimes distinctive enough for individual identification even by human researchers in ecological studies.

Many birds engage in duet calls. In some cases the duets are so perfectly timed as to appear almost as one call. This kind of calling is termed antiphonal duetting. Such duetting is noted in a wide range of families including quails, bushshrike

Bushshrike

The bushshrikes are smallish passerine bird species. They were formerly classed with the true shrikes in the family Laniidae, but are now considered sufficiently distinctive to be separated from that group as the family Malaconotidae....

s, babbler

Old World babbler

The Old World babblers or timaliids are a large family of mostly Old World passerine birds. They are rather diverse in size and coloration, but are characterised by soft fluffy plumage. These are birds of tropical areas, with the greatest variety in Southeast Asia and the Indian Subcontinent...

s such as the scimitar babbler

Scimitar babbler

The scimitar-babblers are birds in the genera Pomatorhinus, Xiphirhynchus and Jabouilleia of the large Old World babbler family of passerines. These are birds of tropical Asia, with the greatest number of species occurring in hills of the Himalayas.Scimitar-babblers are rangy, medium-sized,...

s, some owls and parrots. In territorial songbirds, birds are more likely to countersing when they have been aroused by simulated intrusion into their territory. This implies a role in intraspecies aggressive competition.

Some birds are excellent vocal mimics. In some tropical species, mimics such as the drongo

Drongo

The drongos are a family of small passerine birds of the Old World tropics, the Dicruridae. This family was sometimes much enlarged to include a number of largely Australasian groups, such as the Australasian fantails, monarchs and paradise flycatchers...

s may have a role in the formation of mixed-species foraging flocks

Mixed-species feeding flock

A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species, that join each other and move together while foraging...

. Vocal mimicry can include conspecifics, other species or even man-made sounds. Many hypotheses have been made on the functions of vocal mimicry including suggestions that they may be involved in sexual selection by acting as an indicator of fitness, help brood parasites, protect against predation but strong support is lacking for any function. Many birds, and especially those that nest in cavities, are known to produce a snake like hissing sound that may help deter predators at close range.

Some cave-dwelling species, including Oilbird

Oilbird

The Oilbird , also known as Guácharo, is a bird found in the northern areas of South America . They are nocturnal feeders on the fruits of the Oil Palm and tropical laurels, and are the only nocturnal fruit eating birds in the world...

and Swiftlets (Collocalia
Collocalia
Collocalia is a genus of swifts, containing some of the smaller species termed "swiftlets". Formerly a catch-all genus for these, a number of its erstwhile members are now normally placed in Aerodramus....

and Aerodramus
Aerodramus
Aerodramus is a genus of small, dark, cave-nesting birds in the Collocaliini tribe of the swift family. Its members are confined to tropical and subtropical regions in southern Asia, Oceania and northeastern Australia...

spp.), use audible sound (with the majority of sonic location occurring between 2 and 5 kHz) to echolocate

Animal echolocation

Echolocation, also called biosonar, is the biological sonar used by several kinds of animals.Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects...

in the darkness of caves. The only bird known to make use of infrasound

Infrasound

Infrasound is sound that is lower in frequency than 20 Hz or cycles per second, the "normal" limit of human hearing. Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high...

(at about 20 Hz) is the western capercaillie.

The hearing range of birds is from below 50 Hz (infrasound) to above 20 kHz (ultrasound) with maximum sensitivity between 1 and 5 kHz. The range of frequencies at which birds call in an environment varies with the quality of habitat and the ambient sounds. It has been suggested that narrow bandwidths, low frequencies, low-frequency modulations, and long elements and inter-element intervals should be found in habitats with complex vegetation structures (which would absorb and muffle sounds) while high frequencies, broad bandwidth, high-frequency modulations (trills), and short elements and inter-elements may be expected in habitats with herbaceous cover.
It has been hypothesized that the available frequency range is partitioned and birds call so that overlap between different species in frequency and time is reduced. This idea has been termed the "acoustic niche". Birds sing louder and at a higher pitch in urban areas, where there is ambient low-frequency noise.

Bird Language

The language of the birds

Language of the birds

In mythology, medieval literature and occultism, the language of the birds is postulated as a mystical, perfect divine language, green language, adamic language, enochian language, angelic language or a mythical or magical language used by birds to communicate with the initiated.-History:In...

has long been a topic for anecdote and speculation. That calls have meanings that are interpreted by their listeners has been well demonstrated. Domestic chicken

Chicken

The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...

s have distinctive alarm calls for aerial and ground predators, and they respond to these alarm calls appropriately. However a language

Language

Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...

has, in addition to words, structures and rules. Studies to demonstrate the existence of language have been difficult due to the range of possible interpretations. Research on parrot

Parrot

Parrots, also known as psittacines , are birds of the roughly 372 species in 86 genera that make up the order Psittaciformes, found in most tropical and subtropical regions. The order is subdivided into three families: the Psittacidae , the Cacatuidae and the Strigopidae...

s by Irene Pepperberg is claimed to demonstrate the innate ability for grammatical structures, including the existence of concepts such as nouns, adjectives and verbs. Studies on starling

Starling

Starlings are small to medium-sized passerine birds in the family Sturnidae. The name "Sturnidae" comes from the Latin word for starling, sturnus. Many Asian species, particularly the larger ones, are called mynas, and many African species are known as glossy starlings because of their iridescent...

vocalizations have also suggested that they may have recursive structures.

The term "bird language" may also more informally refer to patterns in bird vocalizations that communicate information to other birds or other animals in general. Wilderness Awareness School groups bird vocalizations into five different classes, sometimes called "voices," each of which communicates different information. Song has been discussed at length in this article. Companion calling is a short vocalization made between mates, parent and young, or members of a flock to maintain contact when out of visual range. Juvenile begging is a strident, loud vocalization often made by young to a parent when begging for food. Intraspecific aggression can consist of loud, alarmed-sounding vocalizations or of energetic song, and may be heard when members of the same species behave aggressively toward each other. Alarm may be heard when birds are startled, frightened, or terrified for their lives, and can take many forms. Mobbing is one example of alarm, while a high-pitched alarm call is another.

Of the five voices of the birds, four of them communicate the message that the bird feels safe. Birds that engage in song, companion calling, juvenile begging, and intraspecific aggression all display what Jon Young calls "baseline" behavior, or a relaxed state free of the fear of predation. Alarm communicates the presence of a predator, or an influence that the bird may see as predatory such as a human hiker. Alarms have distinct sounds and shapes, each of which is specific to the source of the disturbance. For example, raven

Raven

Raven is the common name given to several larger-bodied members of the genus Corvus—but in Europe and North America the Common Raven is normally implied...

s mobbing a hawk or owl in a tree will clump around the predator in a loose ball, calling and diving. If the ravens rise off the tree and fly higher, the predator was a hawk and has flown up to escape, as is typical of hawks. If the ravens drop out of the tree and fly low and away, the predator was an owl and has dropped low off its perch to escape, as is typical of owls.

Neurophysiology

The main brain areas involved in bird song are:

Anterior forebrain pathway (vocal learning
Vocal learning
Vocal learning is the ability of animals to modify vocal signals in form as a result of experience with those of other individuals. This can lead to signals that are either similar or dissimilar to the model...

): composed of the lateral part of the magnocellular
Magnocellular neurosecretory cell
Magnocellular neurosecretory cells are large cells within the supraoptic nucleus and paraventricular nucleus of the hypothalamus. They are also found in smaller numbers in accessory cell groups between these two nuclei, the largest one being the nucleus circularis...

nucleus of anterior neostriatum (LMAN), which is a homologue to mammalian basal ganglia
Basal ganglia
The basal ganglia are a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit. They are situated at the base of the forebrain and are strongly connected with the cerebral cortex, thalamus and other brain areas...

); Area X, which is part of the basal ganglia; and the Dorso-Lateral division of the Medial thalamus (DLM).
Song production pathway: composed of the HVC
High vocal center
The HVC is a nucleus in the brain of the songbirds necessary for both the learning and the production of bird song...

(sometimes, inaccurately, called the hyperstriatum ventrale, pars caudalis); robust nucleus of the arcopallium (RA); and the tracheosyringeal part of the hypoglossal nucleus (nXIIts).

Both pathways show sexual dimorphism

Sexual dimorphism

Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

, with the male producing song most of the time. It has been noted that injecting testosterone

Testosterone

Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands...

in non-singing female birds can induce growth of the HVC and thus production of song.

Birdsong production is generally thought to start at the nucleus uvaeformis of the thalamus

Thalamus

The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...

with signals emanating along a pathway that terminates at the syrinx. The pathway from the thalamus leads to the interfacial nucleus of the nidopallium to the HVC, and then to RA, the dorso-lateral division of the medial thalamus and to the tracheosyringeal nerve.

The gene FOXP2

FOXP2

Forkhead box protein P2 also known as FOXP2 is a protein that in humans is encoded by the FOXP2 gene, located on human chromosome 7 . FOXP2 orthologs have also been identified in all mammals for which complete genome data are available...

, defects of which affect both speech and comprehension of language in humans, becomes more active in the striatal region of songbirds during the time of song learning.

Recent research in birdsong learning has focused on the Ventral Tegmental Area

Ventral tegmentum

The ventral tegmentum , better known as the ventral tegmental area , is a group of neurons located close to the midline on the floor of the midbrain...

(VTA), which sends a dopamine

Dopamine

Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...

input to the para-olfactory lobe and Area X, LMAN and the ventrolateral medulla. Other researchers have explored the possibility that HVc

High vocal center

The HVC is a nucleus in the brain of the songbirds necessary for both the learning and the production of bird song...

is responsible for syllable production, while the robust nucleus of the arcopallium, the primary song output nucleus, may be responsible for syllable sequencing and production of notes within a syllable.

Learning

The songs of different species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

of birds vary, and are more or less characteristic of the species. In modern-day biology

Biology

Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

, bird song is typically analysed using acoustic spectroscopy

Spectrogram

A spectrogram is a time-varying spectral representation that shows how the spectral density of a signal varies with time. Also known as spectral waterfalls, sonograms, voiceprints, or voicegrams, spectrograms are used to identify phonetic sounds, to analyse the cries of animals; they were also...

. Species vary greatly in the complexity of their songs and in the number of distinct kinds of song they sing (up to 3000 in the Brown Thrasher

Brown Thrasher

The Brown Thrasher , sometimes erroneously called the Brown Thrush, is a bird in the Mimidae family, a group that also includes the New World catbirds and mockingbirds.-Description:...

); in some species, individuals vary in the same way. In a few species such as starling

Starling

s and mockingbird

Mockingbird

Mockingbirds are a group of New World passerine birds from the Mimidae family. They are best known for the habit of some species mimicking the songs of other birds and the sounds of insects and amphibians, often loudly and in rapid succession. There are about 17 species in three genera...

s, songs imbed arbitrary elements learned in the individual's lifetime, a form of mimicry (though maybe better called "appropriation" [Ehrlich et al.], as the bird does not pass for another species). As early as 1773 it was established that birds learnt calls and cross-fostering

Cross-fostering

Cross-fostering is a technique used in animal husbandry, animal science, genetic and nature versus nurture studies, and conservation, whereby offspring are removed from their biological parents at birth and raised by surrogates. This can also occasionally occur in nature.-Animal...

experiments were able to force a Linnet Acanthis cannabina to learn the song of a skylark Alauda arvensis. In many species it appears that although the basic song is the same for all members of the species, young birds learn some details of their songs from their fathers, and these variations build up over generations to form dialect

Dialect

The term dialect is used in two distinct ways, even by linguists. One usage refers to a variety of a language that is a characteristic of a particular group of the language's speakers. The term is applied most often to regional speech patterns, but a dialect may also be defined by other factors,...

s.

Birds learn songs early in life with sub-vocalizations that develop into renditions of adult songs. Zebra Finch

Zebra Finch

The Zebra Finch, Taeniopygia guttata, is the most common and familiar estrildid finch of Central Australia and ranges over most of the continent, avoiding only the cool moist south and the tropical far north. It also can be found natively in Indonesia and East Timor...

es, the most popular species for birdsong research, develop a version of a familiar adult's song after 20 or more days from hatch. By around 35 days, the chick will have learned the adult song. The early song is "plastic" or variable and it takes the young bird two or three months to perfect the "crystallized" song (which is less variable) of sexually mature birds.

Research indicates birds' acquisition of song is a form of motor learning

Motor learning

Motor learning is a “relatively permanent” change, resulting from practice or a novel experience, in the capability for responding...

that involves regions of the basal ganglia

Basal ganglia

The basal ganglia are a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit. They are situated at the base of the forebrain and are strongly connected with the cerebral cortex, thalamus and other brain areas...

. Models of bird-song motor learning are sometimes used as models for how humans learn speech. In some species such as zebra finches, learning of song is limited to the first year; they are termed 'age-limited' or 'close-ended' learners. Other species such as the canaries

Domestic Canary

The Domestic Canary, often simply known as the canary, is a domesticated form of the wild Canary, a small songbird in the finch family originating from the Macaronesian Islands ....

can develop new songs even as sexually mature adults; these are termed 'open-ended' learners.

Researchers have hypothesized that learned songs allow the development of more complex songs through cultural interaction, thus allowing intraspecies dialects that help birds stay with their own kind within a species, and it allows birds to adapt their songs to different acoustic environments.

Auditory feedback in bird song learning

Early experiments by Thorpe

William Homan Thorpe

William Homan Thorpe FRS was Professor of Animal Ethology at the University of Cambridge, and a significant British zoologist, ethologist and ornithologist....

in 1954 showed the importance of a bird being able to hear a tutor's song. When birds are raised in isolation, away from the influence of conspecific males, they still sing. While the song they produce resembles the song of a wild bird, it lacks the complexity and sounds distinctly different. The importance of the bird being able to hear himself sing in the sensorimotor

Theory of cognitive development

Piaget's theory of cognitive development is a comprehensive theory about the nature and development of human intelligence first developed by Jean Piaget. It is primarily known as a developmental stage theory, but in fact, it deals with the nature of knowledge itself and how humans come gradually to...

period was later discovered by Konishi. Birds deafened before the song crystallization period went on to produce very different songs from the wild type

Wild type

Wild type refers to the phenotype of the typical form of a species as it occurs in nature. Originally, the wild type was conceptualized as a product of the standard, "normal" allele at a locus, in contrast to that produced by a non-standard, "mutant" allele...

. These findings led scientists to believe there could be a specific part of the brain dedicated to this specific type of learning.

The main focus in the search for the neuronal aspect of bird song learning was guided by the song template hypothesis. This hypothesis is the idea that when a bird is young he memorizes the song of his tutor. Later, during the development phase as an adult, he matches his own trial vocalizations using auditory feedback to an acoustic template in the brain. Based on this information, he adjusts his song if needed. To find this "song template," experimenters lesion

Lesion

A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :...

ed certain parts of the brain and observed the effects.

Lesioning the song production pathway (RA, xXII or HVc) in the brain creates serious effects on song production in all birds.

Lesions parts of the anterior forebrain pathway, or vocal learning pathway, DLM and area X, result in deficits in learning in all birds.

Lesioning LMAN, located in the anterior forebrain pathway in young birds disrupts song production.

Lesioning LMAN on an adult bird shows no effect.

Lesioning LMAN on an adult canary (an "open-ended learner" species, which can learn songs later in life) shows a progressive deterioration of song.

These results show that the area known as LMAN is the only brain area in the pathway that shows some plasticity

Neuroplasticity

Neuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment. Plasticity occurs on a variety of levels, ranging from cellular changes involved in...

and further studies have shown that this area of the brain responds best to the bird's own song. This neuroplasticity is vital for a bird being able to learn a song. The ability to make small adjustments based on auditory feedback is needed for the complexity of these beautiful songs. Just like any musician, birds need to practice and be able to evaluate what their song sounds like and what it's supposed to sound like in order to get it right.

To complete the picture on bird song learning, experimenters needed to discover the true plasticity of the brain. While deafening and creating auditory isolation were good techniques for discovering basic characteristics about the brain, a reversible procedure was needed to investigate further. The solution was found in disruption of the auditory feedback, or what a bird hears. A computer is able to capture the song of a singing bird and play back portions of its song, or selectively play back a certain syllable while the bird is singing. The computer is basically playing the age old trick of repeating whatever the bird sings, the "stop copying me" game. This creates such a disruption that an adult bird will start to decrystallize its song, which includes a loss of spectral and temporal rigidity characteristic of adult song. It reverts back to the song it started singing with, before any learning took place. Furthermore, when the feedback was stopped, the birds slowly recovered their original song, something that was unheard of. These results show that there is a fair amount of plasticity retained in the brain, even for close-ended learners. This new found plasticity in adult birds and the results on the plasticity of LMAN (shown above) combine into a model for bird song learning (diagram coming soon).

Mirror neurons and vocal learning

A mirror neuron

Mirror neuron

A mirror neuron is a neuron that fires both when an animal acts and when the animal observes the same action performed by another. Thus, the neuron "mirrors" the behaviour of the other, as though the observer were itself acting. Such neurons have been directly observed in primate and other...

is a neuron

Neuron

A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...

that discharges both when an individual performs an action, and when he perceives that same action being performed by another. These neurons were first discovered in macaque

Macaque

The macaques constitute a genus of Old World monkeys of the subfamily Cercopithecinae. - Description :Aside from humans , the macaques are the most widespread primate genus, ranging from Japan to Afghanistan and, in the case of the barbary macaque, to North Africa...

monkeys, but recent research suggests that mirror neuron systems may be present in other animals including humans.

Mirror neurons have the following characteristics:

They are located the premotor cortex
Premotor cortex
The premotor cortex is an area of motor cortex lying within the frontal lobe of the brain. It extends 3 mm anterior to the primary motor cortex, near the Sylvian fissure, before narrowing to approximately 1 mm near the medial longitudinal fissure, which serves as the posterior border for...
They exhibit both sensory and motor properties
They are action-specific – mirror neurons are only active when an individual is performing or observing a certain type of action (e.g.: grasping an object).

Because mirror neurons exhibit both sensory

Sensory neuron

Sensory neurons are typically classified as the neurons responsible for converting external stimuli from the environment into internal stimuli. They are activated by sensory input , and send projections into the central nervous system that convey sensory information to the brain or spinal cord...

and motor

Motor neuron

In vertebrates, the term motor neuron classically applies to neurons located in the central nervous system that project their axons outside the CNS and directly or indirectly control muscles...

activity, some researchers have suggested that mirror neurons may serve to map sensory experience onto motor structures. This has implications for birdsong learning– many birds rely on auditory feedback to acquire and maintain their songs. Mirror neurons may be mediating this comparison of what the bird hears and what he produces.

In search of these auditory-motor neurons, Jonathan Prather and other researchers at Duke University recorded the activity of single neurons in the HVCs

High vocal center

The HVC is a nucleus in the brain of the songbirds necessary for both the learning and the production of bird song...

of swamp sparrow

Swamp Sparrow

The Swamp Sparrow is a medium-sized sparrow related to the Song Sparrow.Adults have streaked rusty, buff and black upperparts with a gray breast, light belly and a white throat. The wings are strikingly rusty. Most males and a few females have a rust-colored caps. Their face is gray with a dark...

s. They discovered that the neurons that project from the HVC to Area X (HVC_X neurons) are highly responsive when the bird is hearing a playback of his own song. These neurons also fire in similar patterns when the bird is singing that same song. Swamp sparrows employ 3-5 different song types, and the neural activity differs depending on which song is heard or sung. The HVC_X neurons only fire in response to the presentation (or singing) of one of the songs, the primary song type. They are also temporally selective, firing at a precise phase in the song syllable.

Because the timing of the neural response is identical regardless of whether the bird was listening or singing, how can we be sure that the bird isn’t just hearing himself? Prather et al. found that during the short period of time before and after the bird sings, his HVC_X neurons become insensitive to auditory

Sound

Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...

input. In other words, the bird becomes "deaf" to his own song. This suggests that these neurons are producing a corollary discharge, which would allow for direct comparison of motor output and auditory input. This may be the mechanism underlying learning via auditory feedback.

Overall, the HVC_X auditory-motor neurons in swamp sparrows are very similar to the visual-motor mirror neurons discovered in primates. Like mirror neurons, the HVC_X neurons:

Are located in a premotor brain area
Exhibit both sensory and motor properties
Are action-specific – a response is only triggered by the ‘primary song type’

The function of the mirror neuron system is still unclear. Some scientists speculate that mirror neurons may play a role in understanding the actions of others, imitation

Imitation

Imitation is an advanced behavior whereby an individual observes and replicates another's. The word can be applied in many contexts, ranging from animal training to international politics.-Anthropology and social sciences:...

, theory of mind

Theory of mind

Theory of mind is the ability to attribute mental states—beliefs, intents, desires, pretending, knowledge, etc.—to oneself and others and to understand that others have beliefs, desires and intentions that are different from one's own...

and language acquisition

Language acquisition

Language acquisition is the process by which humans acquire the capacity to perceive, produce and use words to understand and communicate. This capacity involves the picking up of diverse capacities including syntax, phonetics, and an extensive vocabulary. This language might be vocal as with...

, though there is currently insufficient neurophysiological

Neurophysiology

Neurophysiology is a part of physiology. Neurophysiology is the study of nervous system function...

evidence in support of these theories. Specifically regarding birds, it is possible that the mirror neuron system serves as a general mechanism underlying vocal learning

Vocal learning

Vocal learning is the ability of animals to modify vocal signals in form as a result of experience with those of other individuals. This can lead to signals that are either similar or dissimilar to the model...

, but further research is needed. In addition to the implications for song learning, the mirror neuron system could also play a role in territorial behaviors such as song-type matching and countersinging.

Identification and systematics

The specificity of bird calls has been used extensively for species identification. The calls of birds have been described using words or nonsense syllables, or line diagrams. Common terms in English include words such as quack, chirp and chirrup. These are subject to imagination and vary greatly; a well-known example is the White-throated Sparrow

White-throated Sparrow

The White-throated Sparrow is a passerine bird of the American sparrow family Emberizidae.-Description:The White-throated Sparrow is a passerine bird of the American sparrow family Emberizidae...

's song, given in Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

as O sweet Canada Canada Canada and in New England

New England

New England is a region in the northeastern corner of the United States consisting of the six states of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut...

as Old Sam Peabody Peabody Peabody (also Where are you Frederick Frederick Frederick?). In addition to nonsense words, grammatically correct phrases have been constructed as likenesses of the vocalizations of birds. For example, the Barred Owl

Barred Owl

The Barred Owl is a large typical owl. It goes by many other names, including eight hooter, rain owl, wood owl, and striped owl, but is probably best known as the hoot owl.-Description:...

produces a motif which some bird guides describe as Who cooks for you? Who cooks for you all? with the emphasis placed on you.

The use of spectrogram

Spectrogram

s to visualize bird song was first introduced by W. H. Thorpe. These visual representations are also called sonograms or sonagrams. Some recent field guides for birds use sonograms to document the calls and songs of birds. The sonogram is objective, unlike descriptive phrases, but proper interpretation requires experience. Sonograms can also be roughly converted back into sound.

Bird song is an integral part of bird courtship and is a pre-zygotic isolation mechanism involved in the process of speciation

Speciation

Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...

. Many allopatric

Allopatric speciation

Allopatric speciation or geographic speciation is speciation that occurs when biological populations of the same species become isolated due to geographical changes such as mountain building or social changes such as emigration...

sub-species show differences in calls. These differences are sometimes minute, often detectable only in the sonograms. Song differences in addition to other taxonomic attributes have been used in the identification of new species. The use of calls has led to proposals for splitting of species complexes such as those of the Mirafra
Mirafra
Mirafra is a genus of lark in the Alaudidae family. Three of its species are sometimes separated in Calendulauda. Some Mirafra species are called "larks", while others are called "bushlarks".-Species list in taxonomic order:Mirafra larks...

Bushlarks.

Recording

The first known recording of birdsong was made in 1889 by Ludwig Koch

Ludwig Karl Koch

Ludwig Karl Koch MBE was a broadcaster and sound recordist. An expert on recording animal sounds, he played a significant part in increasing the British public's appreciation of wildlife....

, who went on to become an eminent wildlife recordist and BBC natural history presenter.

Other notable birdsong recordists include Eric Simms

Eric Simms (ornithologist)

Eric Arthur Simms, DFC was an English ornithologist, naturalist, writer, sound recordist broadcaster and conservationist, as well as a decorated wartime Bomber Command bomb-aimer....

and Chris Watson

Chris Watson (musician)

Christopher Richard Watson is a Sheffield-born musician and sound recordist specialising in natural history. He was a founding member of the musical group Cabaret Voltaire, and Watson's work as a wildlife sound recordist has covered television documentaries and experimental musical collaborations.-...

Bird song and music

Some musicologists believe that birdsong has had a large influence on the development of music. Although the extent of this influence is impossible to gauge, it is sometimes easy to see some of the specific ways composers have integrated birdsong with music.

There seem to be three general ways musicians or composers can be affected by birdsong: they can be influenced or inspired (consciously or unconsciously) by birdsong, they can include intentional imitations of bird song in a composition, or they can incorporate recordings of birds into their works.

In his book 'Why Birds Sing' David Rothernberg claims that birds vocalize traditional scales used in human music, such as the pentatonic scale (e.g. Hermit Thrush) and diatonic scale (e.g. Wood Thrush), providing evidence that birdsong not only sounds like music, but is music in the human sense. This claim has been refuted by Sotorrio ('Tone Spectra') who has shown that birds are not selecting 'scale tones' from a miriad of tonal possibilities, but are 'filtering out' and reinforcing the available set of overtones from the fundamental tones of their vocal chords. This requires "far less musical intelligence and deliberate appropriation" and in this regard, he suggests birdsong has something in common with Mongolian throat-singing and jaw-harp music. Sotorrio also claims that musicians like Rothernberg are deceived by "a perculiar form of Pareidolia" whereby complex tonal information is reduced to human scale concepts due to a "fixation on music as it is written rather than as it sounds". Rothernberg's claims were expored in the BBC documentary 'Why Birds Sing'.

Compositions that imitate or use birdsong

One early example of a composition that imitates birdsong is Janequin's "Le Chant Des Oiseaux", written in the 16th century.

Other composers who have quoted birds or have used birdsong as a compositional springboard include Vivaldi

Antonio Vivaldi

Antonio Lucio Vivaldi , nicknamed because of his red hair, was an Italian Baroque composer, priest, and virtuoso violinist, born in Venice. Vivaldi is recognized as one of the greatest Baroque composers, and his influence during his lifetime was widespread over Europe...

(Spring from the Four Seasons)), Biber

Heinrich Ignaz Biber

Heinrich Ignaz Franz Biber von Bibern was a Bohemian-Austrian composer and violinist. Born in the small Bohemian town of Wartenberg , Biber worked at Graz and Kroměříž before he illegally left his Kroměříž employer and settled in Salzburg...

(Sonata Representativa), Beethoven (Sixth Symphony), Wagner (Siegfried) and the jazz musicians Paul Winter

Paul Winter

Paul Winter is an American saxophonist , and is a six-time Grammy Award nominee.- Biography :Paul Winter attended Altoona Area High School and graduated in 1957...

(Flyway) and Jeff Silverbush (Grandma Mickey).
The twentieth-century French composer Olivier Messiaen

Olivier Messiaen

Olivier Messiaen was a French composer, organist and ornithologist, one of the major composers of the 20th century. His music is rhythmically complex ; harmonically and melodically it is based on modes of limited transposition, which he abstracted from his early compositions and improvisations...

composed with birdsong extensively. His Catalogue d'Oiseaux is a seven-book set of solo piano pieces based upon birdsong. His orchestral piece Réveil des Oiseaux is composed almost entirely of birdsong. Many of his other compositions, including Quatuor pour la fin du temps
Quatuor pour la fin du temps
Quatuor pour la fin du temps, also known by its English title Quartet for the End of Time, is a piece of chamber music by the French composer Olivier Messiaen. It was premiered in 1941...

, similarly integrate birdsong.

The Italian composer Ottorino Respighi

Ottorino Respighi

Ottorino Respighi was an Italian composer, musicologist and conductor. He is best known for his orchestral "Roman trilogy": Fountains of Rome ; Pines of Rome ; and Roman Festivals...

, with his The Pines of Rome
Pini di Roma
Pines of Rome is a symphonic poem written in 1924 by the Italian composer Ottorino Respighi and, together with Fontane di Roma and Feste Romane, forms what is sometimes loosely referred to as his "Roman trilogy"...

(1923–1924), may have been the first to compose a piece of music that calls for pre-recorded birdsong. A few years later, Respighi wrote Gli Uccelli ("The birds"), based on Baroque pieces imitating birds.

The Finnish composer Einojuhani Rautavaara

Einojuhani Rautavaara

Einojuhani Rautavaara is a Finnish composer of contemporary classical music, and is one of the most notable Finnish composers after Jean Sibelius.-Life:...

in 1972 wrote an orchestral piece of music called Cantus Arcticus
Cantus Arcticus
Cantus Arcticus, Op. 61, is an orchestral composition by the Finnish composer Einojuhani Rautavaara. It was written in 1972, and is probably his best-known work....

(Opus 61, dubbed Concerto for Birds and Orchestra) making extensive use of pre-recorded birdsongs from Arctic regions, such as migrating swan

Swan

Swans, genus Cygnus, are birds of the family Anatidae, which also includes geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe Cygnini. Sometimes, they are considered a distinct subfamily, Cygninae...

s.

The American jazz musician Eric Dolphy

Eric Dolphy

Eric Allan Dolphy was an American jazz alto saxophonist, flutist, and bass clarinetist. On a few occasions he also played the clarinet and baritone saxophone. Dolphy was one of several multi-instrumentalists to gain prominence in the 1960s...

sometimes listened to birds while he practiced flute. He claimed to have incorporated bird song into some of his improvisational music.

In the 1960s and 1970s, many rock bands included sound effects in their recordings. Birds were a popular choice. The English band Pink Floyd

Pink Floyd

Pink Floyd were an English rock band that achieved worldwide success with their progressive and psychedelic rock music. Their work is marked by the use of philosophical lyrics, sonic experimentation, innovative album art, and elaborate live shows. Pink Floyd are one of the most commercially...

included bird sound effects in many of the songs from their 1969 albums Soundtrack from the Film More and Ummagumma
Ummagumma
Ummagumma is a double album by English progressive rock band Pink Floyd, released in 1969 by Harvest and EMI in the United Kingdom and Harvest and Capitol in the United States...

(for example, Grantchester Meadows

Grantchester Meadows (song)

"Grantchester Meadows" is a song from the second half of the experimental Pink Floyd album Ummagumma. It was written and performed entirely by Roger Waters. The song features Waters' lyrics accompanied by an acoustic guitar, while a tape loop of a skylark chirps in the background throughout the...

). Similarly, the English singer Kate Bush

Kate Bush

Kate Bush is an English singer-songwriter, musician and record producer. Her eclectic musical style and idiosyncratic vocal style have made her one of the United Kingdom's most successful solo female performers of the past 30 years.In 1978, at the age of 19, Bush topped the UK Singles Chart...

incorporated bird sound effects into much of the music on her 2005 album, Aerial

Aerial (album)

Aerial is the eighth studio album by British singer-songwriter and musician Kate Bush.-Overview:Aerial is Bush's first double album, and was released after a twelve year absence from the music industry during which Bush devoted her time to family and the rearing of her son, Bertie...

.

The Music hall

Music hall

Music Hall is a type of British theatrical entertainment which was popular between 1850 and 1960. The term can refer to:# A particular form of variety entertainment involving a mixture of popular song, comedy and speciality acts...

artist Ronnie Ronalde

Ronnie Ronalde

Ronnie Ronalde is a British music hall singer and siffleur. Ronalde is famous for his voice, whistling, yodelling, imitations of bird song and stage personality...

has gained notoriety for his whistling imitations of birds and for integrating birdsong with human song. His songs 'In A Monastery Garden' and 'If I Were A Blackbird' include imitations of the blackbird, his "signature bird."

The French composer François-Bernard Mâche

François-Bernard Mâche

François-Bernard Mâche is a French composer of contemporary music. Born into a family of musicians, he is a former student of Émile Passani and Olivier Messiaen and has also received a diploma in Greek archaeology and a teaching certificate...

has been credited with the creation of zoomusicology

Zoomusicology

Zoomusicology is a field of musicology and zoology or more specifically, zoosemiotics. Zoomusicology is the study of the music of animals, or rather the musical aspects of sound or communication produced and received by animals....

, the study of the music of animals. His essay Musique, mythe, nature, ou les Dauphins d'Arion (1983) includes a study of "ornitho-musicology", in which he speaks of "animal musics" and a longing to connect with nature.

The German DJ, techno music producer and naturalist

Naturalist

Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...

Dominik Eulberg

Dominik Eulberg, born in 1978 in Westerwald, Germany is an electronic music artist and DJ who has released numerous singles as well as full-length albums on labels such as Cocoon Recordings and Traum Schallplatten...

is an avid bird watcher, and several tracks by him prominently feature sampled bird sounds and even are titled after his favourite specimens.

The productions of The Jewelled Antler Collective often use field recording

Field recording

Field recording is the term used for an audio recording produced outside of a recording studio. The recording is typically recorded in the same channel format as the desired result, for instance, stereo recording equipment will yield a stereo product...

s featuring birdsong.

In 2007, The CT Collective issed two free albums devoted to music made using bird songs (one with human interaction, one without). The project was co-ordinated by looping musician Nick Robinson

Nick Robinson (origami)

Nick Robinson is a British paperfolder best known for publishing books of paper aeroplanes. He was awarded the Sydney French medal in 2004 by the British Origami Society. He has written over thirty books of origami including Origami for Dummies. His origami designs are usually simple and elegant...

Bird song and poetry

Bird song is a popular subject in poetry. Famous poems inspired by bird song include Percy Bysshe Shelley

Percy Bysshe Shelley

Percy Bysshe Shelley was one of the major English Romantic poets and is critically regarded as among the finest lyric poets in the English language. Shelley was famous for his association with John Keats and Lord Byron...

's To a Skylark ("Hail to thee, blithe Spirit!/Bird thou never wert") and Gerard Manley Hopkins

Gerard Manley Hopkins

Gerard Manley Hopkins, S.J. was an English poet, Roman Catholic convert, and Jesuit priest, whose posthumous 20th-century fame established him among the leading Victorian poets...

' Sea and Skylark. Birdsongs and their relations to Middle-earth

Middle-earth

Middle-earth is the fictional setting of the majority of author J. R. R. Tolkien's fantasy writings. The Hobbit and The Lord of the Rings take place entirely in Middle-earth, as does much of The Silmarillion and Unfinished Tales....

inhabitants are a common motif in J. R. R. Tolkien

J. R. R. Tolkien

John Ronald Reuel Tolkien, CBE was an English writer, poet, philologist, and university professor, best known as the author of the classic high fantasy works The Hobbit, The Lord of the Rings, and The Silmarillion.Tolkien was Rawlinson and Bosworth Professor of Anglo-Saxon at Pembroke College,...

's literary work. The Grateful Dead performed a song called "Bird Song" that Jerry Garcia

Jerry Garcia

Jerome John "Jerry" Garcia was an American musician best known for his lead guitar work, singing and songwriting with the band the Grateful Dead...

wrote and dedicated to Janis Joplin

Janis Joplin

Janis Lyn Joplin was an American singer, songwriter, painter, dancer and music arranger. She rose to prominence in the late 1960s as the lead singer of Big Brother and the Holding Company and later as a solo artist with her backing groups, The Kozmic Blues Band and The Full Tilt Boogie Band...

External links

Bird Language: Exploring the Language of Nature with Jon Young A blog with stories and tips for learning the patterns in bird vocalizations.
Large collection of audio bird calls collected in Arizona from Ask A Biologist
Ask A Biologist
Ask A Biologist is a science outreach program originating from Arizona State University's School of Life Sciences.-About the program:Ask A Biologist is a pre-kindergarten through high school program dedicated to answering questions from students, their teachers, and parents...

.
xeno-canto: Community online database of downloadable bird sounds from around the globe ~90000 recordings of ~7700 species as of Nov 2011.
British Library's archive of bird sounds representing more than 8,000 species.
Listen to Nature includes article "The Language of Birds"
Bird songs in movies: an unnatural history Humor piece on soundtrack errors
How do Birds Sing? The mechanics and anatomy of bird song production
Bioacoustic Research Program at the Cornell Lab of Ornithology distributes a number of different free bird song synthesis & analysis programs.
Macaulay Library at the Cornell Lab of Ornithology is the world's largest collection of animal sounds and associated video.
Male shama songs and mimic of sounds
Audio Pitch Tracer Accurate transcription of clean recordings of bird vocalizations to midi

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.