Whale song
As whale song is acoustic communication of whales called. The term "song" (in the English language whale song ) was chosen by whale researchers because a number of whales, especially the baleen whales , communicate with predictable and repetitive stanzas . In this respect the song resembles the bird or human song .
Because of their life in the water, whales and other marine mammals are very dependent on acoustic communication, especially since the optical sense is severely impaired due to the high light absorption and the sense of smell due to the relatively slow distribution of substances in the water.
Whale song is rarely recorded as structure-borne sound of a single whale by contact microphone , but mostly as water- borne sound by an underwater microphone , with which the sound of several whales is received, the louder the closer an individual is to the microphone.
Origin of the song
Humans produce sound by allowing air to flow through the larynx , usually upwards. The opening and closing of the vocal folds creates air packets. Throat , tongue and lips use them to create different sounds or words. The whales produce sound in a completely different way, with the two main groups of whales, the baleen and toothed whales , being clearly different.
Tone formation of toothed whales
The sound spectrum of the toothed whales consists mainly of short, high- frequency clicks and whistles; the long-lasting tone sequences that are classically known as whale singing are less pronounced with them. Single click sounds are mostly used for echolocation , while tone sequences are used for communication. In large dolphin schools there is often a tangle of noises that is sometimes compared to the background noise of children in a playground. However, very little is known about the meaning of the individual tone sequences.
The tones themselves are created when air passes through a spatial structure in the head that corresponds to the human nasal cavity and is known as phonic lips . These phonic lips lie between several air sacs in which the air is stored. All toothed whales, with the exception of the sperm whale, have two pairs of these “lips”, which allows them to independently produce two tones at the same time. The vibration generated by the phonic lips is passed on to the whale's melon . Here the sound is shaped and directed in the right direction to be used for echolocation.
Sound formation of the baleen whales
Baleen whales do not have such phonic lips . Instead, they have a larynx, which obviously plays a role in sound production, but has no vocal cords. To date, the exact mechanism of sound formation has not been clarified, but it must be clearly different from that of humans. Whales don't have to exhale to produce the sounds.
Song of the humpback whales
The stanza-like whale song mentioned at the beginning is characteristic of the humpback whale .
Male humpback whales typically sing during mating season , on which the assumption is based that verse singing is used to select mates . It is not known whether it is behavior towards the rival (acoustic rivalry) or whether it should be impressive towards the female.
Researchers Roger Payne and Scott McVay carried out the first scientific investigations into whale song in 1971. They could see a hierarchical structure of the tones. The basic units of the song are therefore individual, uninterrupted tone sequences that last for several seconds.
Four to six of these basic units form a partial stanza, two partial stanzas in turn represent a stanza. A whale normally repeats the same stanza over a period of two to four minutes. This part is known as the " topic ". Several of these "themes" in a row make up the "singing", which lasts about 20 minutes. The same “song” is sung over and over for hours or even days. This hierarchy was referred to as " doll in doll " ( russian doll ) .
Every whale song develops over a period of time. For example, a stanza that begins with a heightened tone ("upsweep") can be rearranged over the course of a month so that this area is replaced by a constant tone. Other parts get a little louder or quieter over time. The speed of these changes also varies. There are years in which the whales constantly vary their songs, while in other years they remain constant over a longer period of time.
Humpback whales, which live in the same regions, usually have very similar songs with only very slight differences. In contrast, whales from geographically completely separate areas have very different songs. Old verses are not re-recorded as the chants are developed. A study over a period of 19 years was able to show that although general parts keep recurring, they are never in the same combination.
In addition to the songs, humpback whales also produce sounds that are not structured like stanzas, for example to delimit territorial areas. A third group of humpback whale tones are the so-called feeding calls . This is a continuous tone of between five and ten seconds with approximately the same frequency . This is used when hunting together, in which several whales stay below schools of fish and constrict them into a bubble curtain by blowing out air, and then appear in the school from below with their mouths open. Before they build up the bubble carpet, this tone sounds. Obviously the fish also react to the sound. It has been proven that when the noise is heard, individual fish flee the main school, regardless of whether there are whales nearby.
Due to the good sound conductivity of the water and the low frequency of the sound waves emitted, the chants can still be heard from a great distance. Several hundred to several thousand kilometers are specified as the possible distance between the singing animal and the recipient.
Other kinds
Most other whales produce sounds of varying degrees of complexity. The beluga in particular is characterized by an immense spectrum of tones, which gave it the name Sea Canary ( canary of the sea).
In blue whales , it has been observed that the pitch of their songs has dropped significantly since the 1960s. The reason for this is unclear; It is believed that the whales have to communicate over less great distances than in the 1960s, as the population density increased as a result of the discontinuation of commercial hunting. A deep song of the male whales also signals a large volume of lungs and body, which is why female whales may prefer larger animals when choosing a partner.
It has been observed that the mothers of the northern capers attenuate the volume of their singing in the presence of their young calves. As a possible explanation, the researchers cited camouflage from predators , such as B. Sharks and Orcas . The general social isolation of mothers and their calves was found to be possibly also causal, since communication over long distances is not required during this time.
Bowhead whales sing 24 hours a day from April to November, and their song is highly variable. Researchers managed to distinguish 184 "songs".
People and whale songs
While some observers explain the fascination of whale songs with the fact that the animals are marine animals, many researchers believe that whale song plays an important role in the development and above all for the well-being of the animals and this is also carried over to humans. Opponents of whaling are often accused of using the whale songs for their own cause and to support their position by wanting to bind people emotionally to the whales with the humanized songs. Whaling organizations often downplay the importance of song.
Those who consider whale song and communication to be an important part of whale life are most concerned about the increase in sounds in the oceans and their effects on whales. Studies of killer whales in the Vancouver area showed that the more boat traffic increased, the animals changed the frequency of their calls and also increased the volume in order to still hear the signals. Environmentalists fear a massive increase in stress for the animals from this acoustic pollution. They suspect a connection between whale strandings and the use of military sonars , which disrupt the animals' sense of direction.
The Whalesong project has been taking place on the island of Maui (Hawaii) for several years . Every winter during the whale season, a group including the founder Dan Sythe ensures that a hydrophone is hung from a buoy in the water off the coast of the city of Kihei in southern Maui , from which the local whale songs and noises live 24 hours a day maximum delay of eight seconds can be heard over the Internet.
The sounds on the Voyager Golden Record include whale songs.
Sound samples
| Song of a humpback whale: | |
| Humpback whale song on a windy day: | |
| "Song" of the great killer whale: | |
| Killer whale removed: | |
| Killer whale: |
Other audio material
- Roger Payne : Songs of the Humpback Whale. CRM Records, 1970.
- Wolfgang Tins: Whale voices. Songs and calls from below. Musikverlag Edition Ample, Germering 2000, ISBN 978-3-935329-01-9 .
literature
- Adam S. Frankel: Sound production. In: Encyclopedia of Marine Mammals. Academic Press, San Diego / London 2002, ISBN 0-12-551340-2 , pp. 1126-1137.
Web links
- The Whalesong Project
- The art of singing with syntax (researcher: "The songs of humpback whales have internal structures like human languages")
Individual evidence
- ↑ Compare: Sound generator: The Monkey Lips / Dorsal Bursae Complex (MLDB) Best Dolphin Head Diagram - 1550oldoakroad.com pinterest.com
- ↑ Ted W. Cranford er al .: Observation and analysis of sonar signal generation in the bottlenose dolphin (Tursiops truncatus): Evidence for two sonar sources. In: Journal of Experimental Marine Biology and Ecology. Volume 407, No. 1, 2011, pp. 81-96, doi: 10.1016 / j.jembe.2011.07.010 .
- ↑ George Dvorsky, Levi Gadye: Why Whale Songs Are Still One Of Science's Greatest Mysteries. In: Gizmodo. March 19, 2015, accessed December 21, 2020.
- ↑ THE JAZZ MUSICIANS OF THE SEAS - VERY BEAUTIFUL GROOVY BOWLLAND WHALES. In: mdr knowledge. July 25, 2019, accessed December 21, 2020.
- ↑ a b c Adam S. Frankel: Sound production. In: Encyclopedia of Marine Mammals. Academic Press, San Diego / London 2002, ISBN 0-12-551340-2 , pp. 1126-1137.
- ^ Mark A. McDonald et al .: Worldwide decline in tonal frequencies of blue whale songs. Endangered Species Research, Volume 9, 2009, pp. 13-21, doi: 10.3354 / esr00217 , full text (PDF; 817 kB).
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^ Susan E. Parks et al .: Acoustic crypsis in communication by North Atlantic right whale mother - calf pairs on the calving grounds. In: Biology Letters. Volume 15, No. 10, 2019, doi: 10.1098 / rsbl.2019.0485
Acoustic camouflage: whale mothers whisper to the children. Retrieved October 14, 2019 . - ↑ KM Stafford er al .: Extreme diversity in the songs of Spitsbergen's bowhead whales. In: Biology Letters. Volume 14, No. 4, 2018, doi: 10.1098 / rsbl.2018.0056 .
- ↑ See the report by the Federal Agency for Nature Conservation on the effects on marine species .
- ↑ See also the documentary Sonic Sea from 2016, which assumes 16 whales stranded on the west coast of the Bahamas in 2000 and is justified in the rapid growth of commercial shipping (engines and above all cavitation ), in the use of air cannons (impulse sound) for mapping the sea floor by the oil industry, and the so-called active sonar system of the US Navy. Film website (in English), Sonic Sea on YouTube (in English).
- ↑ Michael Moorstedt: 120 pictures, two dozen songs and a few noises. In: Süddeutsche. September 3, 2017, accessed December 21, 2020.
