“It is alright that we are blind, because we have internal compass!”

The Blind Mole Rat

Blind mole rats (Spalax ehrenbergi), as the name suggested, they are totally blinded. Not only does this animal lack of eyesight, they dig and inhabit in their own tunnel system which has no above ground exits. What so special about these creatures is that they possess a rare talent, that is they are able to use the Earth’s magnetic field on long journeys, much like a compass, to continuously monitor and maintain its course.

To forage for food, these creatures have to dig over a great distance; hence they are not able to afford to make navigational mistakes. While, sighted animals like us are able to make use of the visual landmarks to alter our directions, the blind mole rats make use of magnetic field to change their navigational strategy accordingly.
In the experiments done by Talikimchi and Joseph Terkel, results shown that these creatures were less likely to lost their way under the altered magnetic field when they had to travel short distances. This result indicates that the blind mole rats will switch to using the Earth’s magnetic field as a reference point when navigating over long distances.
Another interesting research found by Talikimchi and Joseph Terkel published in the November 2003 issue of the science journal Animal Behaviour, shows that blind mole rats have another special ability that is that they are able to detect dangers before they encounter it. During the study, the creature’s tunnels were being blocked. However, they were able to dig another shortest route around the obstacles to reconnect them. Amazingly, these creatures left a safe margin of 10 to 20 cm. when an obstacle was placed asymmetrically across the tunnel, the mole rats always detoured it on the shorter side. The scientists believe that these creatures are able to detect dangers by using seismic waves that was generated by banging their heads against the earth.
I was really amazed by the blind mole rats’ ability to direct their way using magnetic field, and most importantly, they are able to predict dangers ahead and thus avoid them.

References:

1) Magnetic Compass Orientation in the blind mole rat (Spalax Ehrenbergi). By Talikimchi and Joseph Terkel. Department of Zoology, George S. Wise Faculty of Life Sciences. Accepted 21 November 2000; published on 1 February 2001. URL: http://www.britannica.com/bps/additionalcontent/18/12261107/How-blind-mole-rats-find-their-way-home

2) Subterranean Rodents: News from Underground. By Sabine Begall, Hynek Burda and Cristian E. Schleich . Publisher Springer Berlin Heidelberg. ISBN 978-3-540-69275-1 (Print) 978-3-540-69276-8 (Online). Page 3-9. (Accessed: 6 Apr 2010)

3) “Rat Radar: Rodent Uses Natural “GPS”” by John Pickrell in England. National Geographic News. January 29, 2004. URL: http://news.nationalgeographic.com/news/2004/01/0129_040129_blindmolerat.html (Accessed: 6 Apr 2010)

4) “Internal Compass Helps Blind Mole Rat Find Its Way” by Sarah Graham January 20, 2004. URL: http://www.scientificamerican.com/article.cfm?id=internal-compass-helps-bl ( Accessed: 6 Apr 2010)

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