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Whale song

2007 Schools Wikipedia Selection. Related subjects: Mammals

   Humpback whales are well known for their songs
   Enlarge
   Humpback whales are well known for their songs

   Whale song is the sound made by whales to communicate. The word " song"
   is used in particular to describe the pattern of regular and
   predictable sounds made by some species of whales (notably the
   humpback) in a way that is reminiscent of human singing.

   The mechanisms used to produce sound vary from one family of cetaceans
   to another. Marine mammals, such as whales, dolphins, and porpoises,
   are much more dependent on sound for communication and sensation than
   land mammals are (excluding humans), as other senses are of limited
   effectiveness in water. Sight is limited for marine mammals because of
   the way water absorbs light. Smell is also limited, as molecules
   diffuse more slowly in water than air, which makes smelling less
   effective. In addition, the speed of sound in water is roughly four
   times that in the atmosphere at sea level. Because sea-mammals are so
   dependent on hearing to communicate and feed, environmentalists and
   cetologists are concerned that they are being harmed by the increased
   ambient noise in the world's oceans caused by ships and marine seismic
   surveys.

Production of sound

   Humans produce sound by expelling air through the larynx. The vocal
   cords within the larynx open and close as necessary to separate the
   stream of air into discrete pockets of air. These pockets are shaped by
   the throat, tongue, and lips into the desired sound.

   Cetacean sound production differs markedly from this mechanism. The
   precise mechanism differs in the two major suborders of
   cetaceans: the Odontoceti ( toothed whales—including dolphins) and the
   Mysticeti ( baleen whales—including the largest whales, such as the
   Blue Whale).

Toothed whale sound production

   Idealized dolphin head showing the regions involved in sound
   production. This image was redrawn from Cranford (2000).
   Enlarge
   Idealized dolphin head showing the regions involved in sound
   production. This image was redrawn from Cranford (2000).

   Toothed whales do not make the long, low-frequency sounds known as the
   whale song. Instead they produce rapid bursts of high-frequency clicks
   and whistles. Single clicks are generally used for echolocation whereas
   collections of clicks and whistles are used for communication. Though a
   large pod of dolphins will make a veritable cacophony of different
   noises, very little is known about the meaning of the sound. Frankell
   quotes one researcher characterizing listening to such a school as like
   listening to a group of children at a playground.

   The multiple sounds themselves are produced by passing air through a
   structure in the head rather like the human nasal passage called the
   phonic lips. As the air passes through this narrow passage, the phonic
   lip membranes are sucked together, causing the surrounding tissue to
   vibrate. These vibrations can, as with the vibrations in the human
   larynx, be consciously controlled with great sensitivity. The
   vibrations pass through the tissue of the head to the melon, which
   shapes and directs the sound into a beam of sound for echolocation.
   Every toothed whale except the sperm whale has two sets of phonic lips
   and is thus capable of making two sounds independently. Once the air
   has passed the phonic lips it enters the vestibular sac. From there the
   air may be recycled back into the lower part of the nasal complex,
   ready to be used for sound creation again, or passed out through the
   blowhole.

   The French name for phonic lips—museau de singe—translates to "monkey
   lips," which the phonic lip structure is supposed to resemble. New
   cranial analysis using computed axial and single photon emission
   computed tomography scans in 2004 showed that, at least in the case of
   bottlenose dolphins, air may be supplied to the nasal complex from the
   lungs by the palatopharyngeal sphincter, enabling the sound creation
   process to continue for as long as the dolphin is able to hold their
   breath .

Baleen whale sound production

   Baleen whales do not have phonic lip structure. Instead they have a
   larynx that appears to play a role in sound production, but it lacks
   vocal chords and scientists remain uncertain as to the exact mechanism.
   The process, however, cannot be completely analogous to humans because
   whales do not have to exhale in order to produce sound. It is likely
   that they recycle air around the body for this purpose. Cranial sinuses
   may also be used to create the sounds, but again researchers are
   currently unclear how.

Purpose of whale-created sounds

   While the complex and haunting sounds of the Humpback Whale (and some
   Blue Whales) are believed to be primarily used in sexual selection (see
   section below), the simpler sounds of other whales have a year-round
   use. While toothed dolphins (including the Orca) are capable of using
   echolocation (essentially the emission of ultra-sonic beams of sound
   waves) to detect the size and nature of objects very precisely, baleen
   whales do not have this capability. Further, unlike some fish such as
   sharks, a whale's sense of smell is not highly developed. Thus given
   the poor visibility of aquatic environments and the fact that sound
   travels so well in water, human-audible sounds play a role in such
   whales' navigation. For instance, the depth of water or the existence
   of a large obstruction ahead may be detected by loud noises made by
   baleen whales.

The song of the Humpback Whale

   Humpback Whale song spectrogram,— Play audio (OGG format, 57 kB)
   Enlarge
   Humpback Whale song spectrogram,
   — Play audio (OGG format, 57 kB)

   Two groups of whales, the Humpback Whale and the subspecies of Blue
   Whale found in the Indian Ocean, are known to produce the repetitious
   sounds at varying frequencies known as whale song. Marine biologist
   Philip Clapham describes the song as "probably the most complex [songs]
   in the animal kingdom" .

   Male Humpback Whales perform these vocalizations only during the mating
   season, and so it is surmised the purpose of songs is to aid sexual
   selection. Whether the songs are a competitive behavior between males
   seeking the same mate, a means of defining territory or a "flirting"
   behaviour from a male to a female is not known and the subject of
   on-going research. Males have been observed singing while
   simultaneously acting as an "escort" whale in the immediate vicinity of
   a female. Singing has also been recorded in competitive groups of
   whales that are composed of one female and multiple males.

   Interest in whale song was aroused by researchers Roger Payne and Scott
   McVay, who analysed the songs in 1971. The songs follow a distinct
   hierarchical structure. The base units of the song (sometimes loosely
   called the " notes") are single uninterrupted emissions of sound that
   last up to a few seconds. These sounds vary in frequency from 20 Hz to
   10 kHz (the typical human range of hearing is 20 Hz to 20 kHz). The
   units may be frequency modulated (i.e., the pitch of the sound may go
   up, down, or stay the same during the note) or amplitude modulated (get
   louder or quieter). However the adjustment of bandwidth on a
   spectrogram representation of the song reveals the essentially pulsed
   nature of the FM sounds.

   A collection of four or six units is known as a sub- phrase, lasting
   perhaps ten seconds (see also phrase (music)). A collection of two
   sub-phrases is a phrase. A whale will typically repeat the same phrase
   over and over for two to four minutes. This is known as a theme. A
   collection of themes is known as a song. The whale will repeat the same
   song, which last up to 30 or so minutes, over and over again over the
   course of hours or even days. This " Russian doll" hierarchy of sounds
   has captured the imagination of scientists.

   All the whales in an area sing virtually the same song at any point in
   time and the song is constantly and slowly evolving over time. For
   example, over the course of a month a particular unit that started as
   an "upsweep" (increasing in frequency) may slowly flatten to become a
   constant note. Another unit may get steadily louder. The pace of
   evolution of a whale's song also changes—some years the song may change
   quite rapidly, whereas in other years little variation may be recorded.
   Idealized schematic of the song of a Humpback Whale.Redrawn from Payne,
   et al. (1983)
   Enlarge
   Idealized schematic of the song of a Humpback Whale.
   Redrawn from Payne, et al. (1983)

   Whales occupying the same geographical areas (which can be as large as
   entire ocean basins) tend to sing similar songs, with only slight
   variations. Whales from non-overlapping regions sing entirely different
   songs.

   As the song evolves it appears that old patterns are not revisited. An
   analysis of 19 years of whale songs found that while general patterns
   in song could be spotted, the same combinations never recurred.

   Humpback Whales may also make stand-alone sounds that do not form part
   of a song, particularly during courtship rituals. Finally, Humpbacks
   make a third class of sound called the feeding call. This is a long
   sound (5 to 10 s duration) of near constant frequency. Humpbacks
   generally feed cooperatively by gathering in groups, swimming
   underneath shoals of fish and all lunging up vertically through the
   fish and out of the water together. Prior to these lunges, whales make
   their feeding call. The exact purpose of the call is not known, but
   research suggests that fish do know what it means. When the sound was
   played back to them, a group of herring responded to the sound by
   moving away from the call, even though no whale was present.

   Some scientists have proposed that humpback whale song may serve an
   echolocative purpose , but has been subject to disagreement .

Other whale sounds

   Most baleen whales make sounds at about 15–20 Hertz. However, marine
   biologists at the Woods Hole Oceanographic Institution reported in the
   New Scientist in December 2004 that they had been tracking a whale in
   the North Pacific for 12 years that was "singing" at 52 Hz. The
   scientists are currently unable to explain this dramatic difference
   from the norm; however, they are sure the whale is a baleen and
   extremely unlikely to be a new species, suggesting that currently known
   species may have a wider vocal range than previously thought.

   Most other whales and dolphins produce sounds of varying degrees of
   complexity. Of particular interest is the Beluga (the "sea canary")
   which produces an immense variety of whistles, clicks and pulses.

Human interaction

   Voyager Golden Records carried whale songs into outer space with other
   sounds representing planet Earth.
   Enlarge
   Voyager Golden Records carried whale songs into outer space with other
   sounds representing planet Earth.

   Though some observers suggest that undue fascination has been placed on
   the whales' songs simply because the animals are under the sea, most
   marine mammal scientists believe that sound plays a particularly vital
   role in the development and well-being of cetaceans. It may be argued
   those against whaling have anthropomorphized the behaviour in an
   attempt to bolster their case. Conversely pro-whaling nations are
   perhaps disposed to downplay the meaning of the sounds, noting for
   example that little account is taken of the "moo" of cattle.

   Researchers use hydrophones (often adapted from their original military
   use in tracking submarines) to ascertain the exact location of the
   origin of whale noises. Their methods allow them also to detect how far
   through an ocean a sound travels. Research by Dr Christopher Clark of
   Cornell University conducted using thirty years worth of military data
   showed that whale noises travel up to 3,000 km. As well as providing
   information about song production, the data allows researchers to
   follow the migratory path of whales throughout the "singing" (mating)
   season.

   Prior to the introduction of human noise production, Clark says the
   noises may have travelled right from one side of an ocean to the other.
   His research indicates that ambient noise from boats is doubling each
   decade. This has the effect of halving the range of whale noises. Those
   who believe that whale songs are significant to the continued
   well-being of whale populations are particularly concerned by this
   increase in ambient noise. Other research has shown that increased boat
   traffic in, for example, the waters off Vancouver, has caused some Orca
   to change the frequency and increase the amplitude of their sounds, in
   an apparent attempt to make themselves heard. Environmentalists fear
   that such boat activity is putting undue stress on the animals as well
   as making it difficult to find a mate.

Whale song in fiction

     * The song of Humpback Whales was a significant plot element of the
       film Star Trek IV: The Voyage Home.
     * In the animated film Finding Nemo, the (fish) character Dory
       believed she could "speak whale", which she performed entirely in
       English with a whale's sing-song voice.
     * In the 2003 Whale Song (novel) by Cheryl Kaye Tardif, killer whales
       and their vocalization play a key role in the story.
     * Whale song was the main plot device in the book Fluke, or, I Know
       Why the Winged Whale Sings by Christopher Moore.
     * Whale song is also a factor in the worldview of uplifted dolphins
       in David Brin's Uplift and Uplift Storm trilogies, comprising
       elements of religion, philosophy, cosmology and poetry.

Selected discography

     * Songs of the Humpback Whale (SWR 118) was originally released in
       1970 by CRM Records from recordings made by Roger Payne and others.
       The LP was later re-released by Capitol Records, and released on CD
       by BGO-Beat Goes On in 2001.
     * Deep Voices: The Second Whale Record (Capitol Records ST-11598) was
       released on LP in 1977 from additional recordings made by Roger
       Payne, and re-released on CD in 1995 by Living Music. It includes
       recordings of humpbacks, blues, and rights.
     * Northern Whales (MGE 19) was released by Music Gallery Editions
       from recordings made by Pierre Ouellet, John Ford, and others
       affiliated with Interspecies Music and Communication Research. It
       includes recordings of belugas, narwhals, orca, and bearded seals.
     * Sounds of the Earth: Humpback Whales (Oreade Music) was released on
       CD in 1999.
     * Rapture of the Deep: Humpback Whale Singing (Compass Recordings)
       was released on CD in 2001.

Listening

     * Whale Songs at the Avant Garde Project has FLAC files made from
       high-quality LP transcriptions available for free download.


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