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Nature

Sound

Ceatacean species have a sophisticated range of sounds, that can be well above the limit of human hearing. Baleen whales produce sounds with subsonic frequencies, rarely above 5kHz , while toothed whales have great range of sound for communication and echolocation use. The sound frequency used in echolocation are clicks at very high frequencies.

The sound is produced in the nasal passage. The sounds are then reflected towards the melon, a fatty mass in the forehead, which seems to function as an acoustic lens, focusing the sound into the directional beam as they leave the head.
Very little is known of the function of sound however sound can be defined into three categories: Tonal whistles, pulsed sounds of very short duration used in echolocation, and pulsed sounds such as cries, grunts, and barks.

Communication

Certain odontocete sound could serve as Acoustic communication as most whistling species are very social and assemble in herds or dozens to thousands of individuals. These social interactions include mating and sexual activity, play, dominance interactions, and maternal behaviour. Non whistling species are generally found alone or in small groups. Most toothed whales are gregarious, they are vocally very active and feed in groups. A Possible explanation of the function of toothed whale sound might well be the use of sound among each other to co-ordinate the activity. Another explanation of the function might well be the use of sound as a so-called signature call. Signature calls are believed to identify the sender of the call.

Echolocation

Odontocete cetaceans use echolocation sounds to detect, localize, and characterize underwater objects. This includes obstacles, prey, and navigation. Echolocation sounds consist of pulsed sound of very short duration. These clicks are demonstrated in several species of odontocetes like Killer whales, dolphins and Sperm whales. Sound produced by the animals larynx are focused by a structure in the head called the melon. When the sounds strikes a target they are reflected as echoes. The echoes are picked up by teh animal’s lower jaw and transmitted to the inner ear. The vibrations received by the inner ear are then converted into signals that can be carried by the nerves to the brain for interpretation.

The Dolphin’s laynx does not have a vocal cord but instead has a ring of muscles that acts as a valve, enabling the animal to control the air flow through the organ. Air under pressure circulates through the animal’s nasal passage, producing clicks and other characteristic sounds. The sounds are directed by being focused in the melon. An oval mass of fatty, waxy material that is located between the blowhole and the end of the head. The sounds are directed towards objects in front of the animal.

Sperm whales produce an almost continual cacophony of clicks. Which are produced by the valvular “lipps of the Museau” de singe as air passes from the right nasal passage into the vestibular sac. Passing down through the left nasal passage and returning up the right passage recycles the air. The spermaceti organ is a reverberation chamber, and the vestibular frontal sacs, at its anterior and paterior ends, receptively, function as acoustic mirror.

Distibution

Cetacean can be found from clear coastal tropical waters to muddy coastal shallows. The habitat has important but predictable influence on their lifestyle from breeding to feeding and their geographical distributions. The Killer whale, Orcinus orca, is the most abundant whale species, distributed from warm tropical waters to cold arctic waters. The Killer whale is also the fastest cetacean swimmers as reach speeds up to 48 kilometres per hour. The largest whale species, probably largest species ever lived is the Blue whale. The Blue whale can reach up to 32 meter.
Migration occurs in respond to seasonal changes in water temperature and availability of prey. However not all whale species migrate, The Humpack whale and the Gray whale travel thousands of kilometres through open ocean or along coastlines.
They have their feeding grounds in the cold arctic or ataractic waters during the short polar summers. Whales migrate from their summer feeding grounds to the warmer tropical waters once autumn has set in. The warmer tropical waters are their breeding grounds and pregnant females give bird to their offspring. The Males also migrate and mate once the female has given birth. When the Polar summer sets in the whales migrate back to their summer feeding grounds.

Feeding

Toothed whales feed on schools fish, squid and crustaceans. Some whales like killer whales might also feed on warm-blooded prey like seals, sharks and penguins. Baleen whales feed on krill and other zooplankton, schooling fish or small squid depending on the size.