Wikibooks: Sensory Systems/Other Animals/Echolocation Toothed Whales

• Published in: The Anatomical Record
• Format: Book
• Language: English
• Subjects: toothed whales
• Online Access: https://en.wikibooks.org/wiki/Sensory_Systems/Other_Animals/Echolocation_Toothed_Whales

= Toothed Whales Echolocation = = Introduction = Marine mammals such as whales dolphins and porpoises have developed sensing abilities that have allowed them to go into deep sea and spread across the world’s oceans. These mammals belong to the order of Cetacea. Toothed whales (Odontocetes) a parvorder of Cetacea which consists of at least 71 species including sperm whales killer whales porpoises and dolphins have acquired an astonishing type of sensing mechanism called echolocation or bio sonar. It allows them to successfully navigate and hunt prey at places where vision is limited due to great depth or turbulences. Research has shown that it provides them with a three dimensional view of their environment and further gives them the ability to differentiate and recognize characteristics of objects which is a key biological benefit. Nachtigall P.E. 1980 Odontocete echolocation performance on object size shape and material Pages 71 95 in Animal Sonar systems ed. R. G. Busnel and J.F. Fish New York Plenum Press Echolocation has therefore played a major role in the evolutionary success of toothed whales which have emerged 34 million years ago. However it is not only used by toothed whales but can be found in all sorts of other animals as well. Microchiropteran bats for example have a highly developed bio sonar system but also shrews two genera of birds and megachiropteran bats make use of this sensing ability. A.D. Grinnell Echolocation I Behavior In Encyclopedia of Neuroscience edited by Larry R. Squire Academic Press Oxford 2009 Pages 791 800 ISBN 9780080450469 = Echolocation = = Principle of Echolocation = The basic principle of echolocation is to obtain information about the environment from the received echoes of emitted sound waves (see Figure Echolocation). Odontocetes produce pulse like clicking sounds in a high frequency range of 10kHz to 200kHz. These clicks are mostly in the ultrasonic range ( 22.1kHz) and thus not perceivable by humans. The duration frequency interval and source level of the created ...