Whale vocalization

While the complex sounds of the humpback whale (and some blue whales) are believed to be primarily used in sexual selection, there are simpler sounds that are created by other species of whales that have an alternative use and are used all year round. Whale watchers have watched mother whales lift their young towards the surface in a playful motion, while making a noise that resembles cooing in humans. This cooing-like noise made by whales seems designed to relax their young Each sound a whale makes could mean something different. The clicking noises whales make are used for navigation. Song of the humpback whale of humpback whale vocalizations. Detail is shown for the first 24 seconds of the 37-second recording below. Interest in whale song was aroused by researchers Katy and Roger Payne as well as Scott McVay after the songs were brought to their attention by a Bermudian named Frank Watlington who was working for the US government at the SOFAR station listening for Russian submarines with underwater hydrophones off the coast of the island. The Paynes released the best-selling Songs of the Humpback Whale in 1970, and the whale songs were quickly incorporated into human music by, among others, singer Judy Collins, as well as George Crumb, Paul Winter, and David Rothenberg. The humpback whale produces a series of repetitious sounds at varying frequencies known as whale song. Marine biologist Philip Clapham describes the song as "probably the most complex in the animal kingdom." Male humpback whales perform these vocalizations often during the mating season, and so it was initially believed the purpose of songs is to aid mate selection. that is more human-like in its complexity than other forms of animal communication like bird songs, which have only linear structure. 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) might slowly flatten to become a constant note. 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. Some scientists have proposed that humpback whale songs may serve an echolocative purpose, but this has been subject to disagreement. Other whale sounds Humpback whales have also been found to make a range of other social sounds to communicate such as "grunts", "groans", "thwops", "snorts" and "barks". In 2009, researchers found that blue whale song has been deepening in its tonal frequency since the 1960s. While noise pollution has increased ambient ocean noise by over 12 decibels since the mid-20th century, researcher Mark McDonald indicated that higher pitches would be expected if the whales were straining to be heard. Killer whales have been observed to produce long range calls that are stereotyped and high frequency travelling distances from as well as short range calls that can travel distances from . Short range calls are reported during social and resting periods while long range are more commonly reported during foraging and feeding. Most other whales and dolphins produce sounds of varying degrees of complexity. Of particular interest are beluga whales, commonly called "sea canaries", which produce an immense variety of whistles, clicks and pulses. One captive male beluga named NOC (pronounced "no-see") was documented spontaneously imitating the vocal patterns of adult male human speech, which are far lower pitched than normal belugas vocalizations; to achieve these frequencies he deliberately overinflated his vestibular sac, which belugas typically use to keep water out of the blowhole, to control the pressure in his nasal tract. It was previously thought that most baleen whales make sounds at about 15–20 hertz. However, a team of marine biologists, led by Mary Ann Daher of the Woods Hole Oceanographic Institution, reported in 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. Scientists have been unable to explain this phenomenon. For humans 52 Hz is a very low sound; it is audible through human ears as a low moaning sound, while normal whales are inaudibly low. It was not expected that this whale was a new species, more so this whale indicated that a currently known species potentially has a much wider vocal range than previously thought. There is disagreement in the scientific community regarding the uniqueness of the whale's vocalization and whether it is a member of a hybrid whale such as the well documented blue and fin whale hybrids. == Mechanisms of sound production ==