In Episode 25 of the APS podcast, Life Lines, the Stanford University professor updates her research from the APS journal Physiology, explaining how elephant vocalizations travel through the ground for great distances, and how other elephants can understand them, just as they understand acoustic sound, which travels through the air. The study in Physiology can be found by clicking here or by following the full link at the end of the release.
Dr. O’Connell-Rodwell is the author of The Elephant’s Secret Sense. You can see videos of some of the elephant communication experiments she describes in the podcast on her Utopia Scientific site. The links to the videos are on this page: http://utopiascientific.org/Research/mushara.html.Discovers seismic communication
At other times, she also noticed a more puzzling behavior: Several elephants would freeze simultaneously, sometimes in mid-stride, and would press their front feet into the ground. They might also roll a foot forward so that only their toes touched the ground. At other times, they would lift a front leg. The behavior reminded her of the behavior she saw in insects that communicate seismically.
She began a series of experiments that eventually found that:
• Low-frequency elephant vocalizations, which are below the threshold of human hearing, travel through the ground in the same waveform as they do in the air. The ground vocalization can travel faster or more slowly than acoustic sound, depending on soil conditions, but has the potential of travelling further as there is no outer limit to how far sounds can travel through the earth.
• When she played a recorded elephant vocalization through the ground only (not through the air), other elephants detected the vocalization.
• Elephants understood the ground-borne vocalizations. For example, they responded appropriately to an alarm call from another elephant by assuming their defensive posture of bunching and freezing. They also responded only to alarm calls of elephants living in the area rather than those made from elephants elsewhere.
Further research revealed that there are two ways elephants ‘hear’ sound waves traveling through the ground:
Somatosensory pathway. Elephants feel the sound wave through their feet and trunks using the somatosensory pathway. Their feet and trunks have a large number of pacinian corpuscles -- cells that detect vibrations. The cells help transmit these vibrations to the brain.
Bone conduction pathway. Elephants detect ground-borne sound waves through their toenails. The vibration travels up the bone and into the middle ear where it vibrates the middle ear bones, just as an acoustic sound would.
Elephants also have anatomical adaptations to help them ‘hear’ these ground-borne vocalizations:
• They have an enlarged malleus, a middle ear bone that plays an important role in hearing. Animals that communicate seismically often have an enlarged malleus as it also facilitates bone conducted detection of vibrations.
• Elephants can close their middle ear canal, forming a closed acoustic tube which enhances bone conduction and blocks out acoustic sound, helping the elephant focus on the vibration pathway.
• They have an acoustically designed foot, with a thick fat pad that perhaps helps in the transmission or conduction of vibrations.
You can find the podcast interview at http://lifelines.libsyn.com/index.php?post_id=524100 and an article on the research in the journal Physiology: http://physiologyonline.physiology.org/cgi/search?sortspec=relevance&author1=O%27Connell-Rodwell&fulltext=&pubdate_year=&volume=&firstpage=.
For more information, please contact Christine Guilfoy at email@example.com or at 301.634.7253.
Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society (APS) has been an integral part of this scientific discovery process since it was established in 1887.
Christine Guilfoy | Newswise Science News
O2 stable hydrogenases for applications
23.07.2018 | Max-Planck-Institut für Chemische Energiekonversion
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
23.07.2018 | Science Education
23.07.2018 | Health and Medicine
23.07.2018 | Life Sciences