Whale vocalization
As the whale song acoustic communication of whales is called. The term "singing" ( whale in the English language song) was chosen by Walforschern, as a number of whales, especially baleen whales, communicates with predictable and repetitive verses. This is similar to the singing of the birds or even the human vocals.
Through their lives in the water whales and other marine mammals are highly dependent on the acoustic communication, especially since the optical sense due to the high light absorption and the sense of smell due to the relatively slow distribution of substances in the water are greatly affected.
Can be made more audible to the human whale songs using an underwater microphone that converts the water noise in a sound pressure corresponding electrical voltage.
- 4.1 Whale Song Project
Emergence of song
People produce sounds by letting air flow through the larynx. By opening and closing of the vocal folds caused air packages. Throat, tongue and lips shapes result in different sounds or texts. The sound production of whales being built on entirely different way, where they are clearly different in the two main groups of whales, the baleen and toothed whales.
Tone formation of toothed whales
The sound spectrum of toothed whales consists mainly of short high-frequency clicks and whistling; the long-lasting tone sequences, which are traditionally known as whale song, are less pronounced in them. Single clicking sounds are mostly used for echolocation, sound sequences, however, for communication. In large pods of dolphins so often results in a confusion of noises, which is sometimes compared to the background noise of children on a playground. About the meaning of each tone sequences, however, very little is known.
The sounds arise even during the passage of air through a space structure in the head, corresponding to the human nasal cavity and is called the phonic lips. This phonic lips are between several air sacs in which the air is stored. All toothed whales except the sperm whales have two pairs of these " lips ", allowing them to produce two tones independently at the same time. The vibration that occurs at the phonic lips is passed in the melon of Wales. Here the clay is molded and guided in the right direction to be used for echolocation.
Tone formation of the baleen whales
Baleen whales have no 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 formation of clay is unknown, but he must be clearly distinguished from that of humans. Whales do not have to breathe in order to produce the sounds.
The song of the humpback whale
The aforementioned disaster -like whale song is indicative of the humpback whale.
Male humpback whales sing only during the mating season, what evolution is based on the assumption that the verse vocals mate choice is. It is unknown whether this is a response to the rivals ( acoustic rivals fight ) or to impressive effect against the females.
The first scientific studies of whale song, the researchers Roger Payne and Scott McVay at in 1971. They were able to recognize a hierarchical structure of sounds. The base units of the song are therefore single, continuous tone sequences that last for several seconds.
Four to six of these basic units form a part verse, part two stanzas in turn provide a verse dar. same verse repeated a whale normally continuously over a period of two to four minutes. This portion is called a "theme". Several of these " issues " in a row give the "singing", which lasts about 20 minutes. The same " song " is sung over several hours or even days over again. This hierarchy was referred to as " doll in a doll" ( russian doll ).
Each whale song develops over a period of time. For example, a verse that starts with an increased tone (" upsweep " ), to be converted in the course of a month so that this area is replaced by a constant tone. Other parts are in time a little louder or quieter. The speed of these changes varies. So there are years in which the whales constantly vary their songs while they will remain unchanged in other years a long time.
Humpback whales that live in the same regions, most have very similar songs partly with only very slight differences. In contrast, whales have geographically completely separate areas of very different songs. During the development of the old chants verses will not be recorded again. So but was a study over a period of 19 years show that while general parts recur from time to time, never in the same combination.
In addition to the songs of humpback whales also produce sounds that are not built like a disaster, such as the delineation of district areas. A third group of Buckelwaltöne are the so-called feeding calls (such as "feed - calls "). It is a between five and ten seconds long, continuous tone approximately the same frequency. This is used in the common hunting, in which several whales standing underneath shoals of fish and constrict them by air blown into a bubble curtain, and then emerge from the bottom with open mouth in the swarm. Before they set up the bubble carpet, this tone will sound. Obviously the fish react to the sound. It has been shown that when the noise sounded individual fish to flee the main swarm, regardless of whether whales are nearby.
Owing to the good sound conductivity of the water and the low frequency of the emitted sound waves can still hear the chants from a great distance. Here, several hundred to few thousand kilometers are indicated as a possible distance between a singing animal and receiver.
Other forms
Most other whales produce sounds of varying complexity. Above all, the beluga is characterized by a huge range of tones, the Canary taught him the name Sea ( canary of the sea).
In blue whales has been observed that the pitch of their songs has declined significantly since the 1960s. The reason for this is unclear; is believed that the whales today need to communicate over great distances less than in the 1960s, as the population density had increased as a result of the cessation of commercial hunting. A deep song of the male whales also signaling a large lung volume and body, which is why female whales may prefer larger animals in mate choice.
Human and whale songs
While some observers explain the outgoing of the whale songs fascination with the fact that they are marine animals in the animals, many researchers believe that the vocals on the whales play an important role in the development and especially for the well- being of the animals are and this translates to humans. Often opponents of whaling is alleged to use the whale songs for their cause and to support their position in that they want to bind the people with the humanized singing emotionally to the whales. Interesting in this context is that organizations who work for whaling, the importance of song play down often.
Those who keep the whale song and the communication of whales as an important part in the lives of whales, especially troubled by the increase in the noise in the oceans and their effects on the whales. Studies of killer whales in the Great Vancouver area showed that the animals with increasing boat traffic changed the frequency of their calls and also increased the volume to hear the signals yet. Environmentalists fear a massive increase of stress for the animals by this acoustic pollution. So they suspect a connection between whale strandings and the use of military sonars, which disturb the sense of the animals.
Whale Song Project
The Whale Song Project will take place on the island of Maui ( Hawaii) for several years. Every winter during the whale season, a group including the founder Dan Sythe take care of it, that is hung in the water off the coast of the town of Kihei to the south Maui, a hydrophone to a buoy, from the 24 hours a day live the local whale songs and sounds with may be a part of a maximum delay of eight seconds over the Internet.