Differences Between Terrestrial And Aquatic Mammals

Terrestrial and aquatic mammals, although from different taxa and completely different environments, communicate over long distance in similar ways, but of course have differences since they evolved from different ancestors. Specific to this paper, elephants and whales are discussed; the way their ears, external or internal, are structures and how each section of their ears function to aid in the process of hearing frequencies from conspecifics. Elephants not only use their large ears to capture frequencies of sound, but they also use fatty cushions in the feet pads to detect vibrations by bone conductions. Whales abandoned their external ears to be able to swim faster, but they have also enhanced their hearing due to the exceptional way …show more content…
They have large ears that function in many ways, specifically in the detection of vibrations and seismic cues due to their ear structure that have three essential parts: the outer ear which captures sounds, a middle ear which filters and amplifies sound, and the cochlea (the inner ear) which is a band-pass filter and transducer of sound into neural impulses (Ketten 1994). Another important functional aspect of the middle ear is that the quantity of sound energy captured by the pinnae and tympanic membrane increases as the size of the membrane increases, so the ossicles in the middle ear endure the vibrations (Nummela 1995). They also use their ears in succession with the fatty pads of their feet to aid in the ability to hear sounds over long distances. The sounds they are able to hear are defined by the terms of the limits to human hearing; lower, infrasound frequencies, which travel over longer distances, than upper, ultrasound frequencies (Garstang 2004). There are two sides to communication, the receiving of sound and the projecting of sound. Elephants verbally communicate through low frequency sounds such as rumbling, clicks, and roars, known as call …show more content…
Seismic communication is more beneficial to use than airborne communication when airborne circumstances are not fitting to the atmospheric conditions of the environment (O’Connell-Rodwell 2007). Elephants have the largest cerebral cortex of all terrestrial animals, so they can process subtle signals from incoming sound. Vibrational signal energy is most dependent on the muscular size of the one producing the sound, and seismic cues are formed through acoustic waves when percussed on the earth’s surface; the percussion sounds can produce short distance, as well as long distance seismic cues, which are most important to the communication in elephants (O’Connell-Rodwell 2007). Bone conduction is detected through seismic cues and elephants are well equipped for this kind of communication detection. Bone conduction detects seismic signals due to the enlarged ossicles that are found in the middle ear, which facilitate independent oscillations of the middle ear bone relative to the skull. Another way elephants detect seismic cues are through certain behaviors known as freezing behavior. Elephant feet are well suited to detect vibrations due to the dense, fatty cushion in their foot pads. This increases their sensitivity to vibrations and when an elephant places more weight on its larger front