Tragus (ear)

Other animals

The tragus is a key feature in many bat species. As a piece of skin in front of the ear canal, it plays an important role in directing sounds into the ear for prey location and navigation via echolocation. Because the tragus tends to be prominent in bats, it is an important feature in identifying bat species. The tragus allows echolocating bat species to vertically discriminate the objects around them, which is key to identifying where prey items and obstacles are in three-dimensional space. In studies where an individual's tragi are temporarily glued out of their normal positions, the bat's navigational acuity is one-fourth as effective as individuals with unmodified tragi. Based on this study, the authors concluded that the tragus's function is to create acoustic cues to determine the direction of a target in the vertical plane. Not all echolocating bats possess tragi, however. Horseshoe bats are one such family; the way in which the outer bottom edge of the ear folds in on itself is thought to function in a similar way to the tragus in other families. File:Brown long-eared bat (Plecotus auritus) - geograph.org.uk - 1415542.jpg| The long tragus of the brown long-eared bat File:Red bat (6022957658).jpg|The curved tragus of the eastern red bat File:Side view of spotted bat -Euderma maculatum- by Paul Cryan.jpg|The blunt tragus of the spotted bat

Additional images

File:Gray908.png|Horizontal section through left ear; upper half of section. File:Slide2COR.JPG|External ear. Right auricle. Lateral view. File:Slide4COR.JPG|External ear. Right auricle. Lateral view.

References

References

1. [http://www.straightdope.com/columns/read/835/why-do-older-men-have-hair-growing-in-their-noses-and-ears "Why do older men have hair growing in their noses and ears?"] from ''[[The Straight Dope]]''
2. Webster. "Tragus : Meanining". Merriam-Webster.
3. "Tragus : Definition". Collins English Dictionary.
4. Muller, Raulf. (2004). "A numerical study of the role of tragus in the big brown bat". Research Gate.
5. "Fistula test". Harley Street E-Clinic.
6. Chiu, C., & Moss, C. F. (2007). The role of the external ear in vertical sound localization in the free flying bat, Eptesicus fuscus. The Journal of the Acoustical Society of America, 121(4), 2227–2235.
7. . (2013). ["Bats of Wisconsin"](http://wiatri.net/Inventory/Bats/AboutBats/images/batsofwisc.pdf).
8. (1982). "Echolocation in bats: the external ear and perception of the vertical positions of targets". Science.
9. (2012). "A natural history of Australian Bats: working the night shift". CSIRO PUBLISHING.