Interesting article and makes me wonder why bats have such good eyesight if it is not used to capture insects (food). This article seems to show that bats which use echo-location for finding food use it exclusively and if it is jammed they do not get the food. What purpose do the eyes function as? Seeing as bats spend most of their lives in low light level conditions, are their eyes working in a different spectrum or frequency range that that used in conditions of white light? Do they have a spectrum of eyesight that allows navigating narrow spaces in total darkness? Yeah, I know my mind works in strange ways but I have to question why something such as eyesight (which takes up a large part of the brain to process) is provided if it is not used for some type of survival technique such as finding food. Ken
Life isn't about waiting for the storm to pass - It's about dancing in the rain. Date: Tue, 30 Dec 2014 21:59:35 +0000 From: dirt...@comcast.net To: s...@caver.net; Texascavers@texascavers.com; tag-...@hiddenworld.net Subject: [SWR] It's bat vs. bat in aerial jamming wars It's bat vs. bat in aerial jamming wars https://www.sciencenews.org/article/its-bat-vs-bat-aerial-jamming-wars?mode=magazine&context=189468&tgt=nr It's bat vs. bat in aerial jamming warsSpecial wavering call sabotages aimBy Susan Milius10:00am, December 19, 2014 SONAR WARS Of the 15 known kinds of squeaks and chirps that a Mexican free-tailed bat makes, one looks like aerial sabotage. Magazine issue: Vol. 186 No. 13, December 27, 2014 In nighttime flying duels, Mexican free-tailed bats make short, wavering sirenlike waaoo-waaoo sounds that jam each other’s sonar. These “amazing aerial battles” mark the first examples of echolocating animals routinely sabotaging the sonar signals of their own kind, says Aaron Corcoran of Wake Forest University in Winston-Salem, N.C. Many bats, like dolphins, several cave-dwelling birds and some other animals, locate prey and landscape features by pinging out sounds and listening for echoes. Some prey, such as tiger moths, detect an incoming attack and make frenzied noises that can jam bat echolocation, Corcoran and his colleagues showed in 2009 (SN: 1/31/09, p. 10). And hawkmoths under attack make squeaks with their genitals in what also may be defensive jamming (SN Online: 7/3/13). But Corcoran didn’t expect bat-on-bat ultrasonic warfare. Mexican free-tailed bats fight sonar wars, jamming each other’s echolocation signals in competitions to snatch moths out of the night sky. Nickolay HristovHe was studying moths dodging bats in Arizona’s Chiricahua Mountains when his equipment picked up a feeding buzz high in the night sky. A free-tailed bat was sending faster and faster echolocation calls to refine the target position during the final second of an attack. (Bats, the only mammals known with superfast muscles, can emit more than 150 sounds a second.) Then another free-tailed bat gave a slip-sliding call. Corcoran, in a grad student frenzy of seeing his thesis topic as relevant to everything, thought the call would be a fine way to jam a buzz. “Then I totally told myself that’s impossible — that’s too good to be true.” Five years later he concluded he wasn’t just hearing things. He and William Conner, also of Wake Forest, report in the Nov. 7 Science that the up-and-down call can cut capture success by about 70 percent. Using multiple microphones, he found that one bat jams another, swoops toward the moth and gets jammed itself. Corcoran says that neighborly sabotage could be especially valuable for the highly sociable Mexican free-taileds (Tadarida brasiliensis). “If you live in a cave with a million bats,” he says, “you have to go out and find food — and compete with a million bats.” JAMMED SIGNAL Three video clips filmed outdoors at night show Mexican free-tailed bats (the larger white shapes) hunting tethered insects (smaller white shapes). The first clip shows a successful midair catch, and the rest show how jamming calls foil the attempts. Credit: A.J. Corcoran et al./Science 2014. DirtDoc _______________________________________________ SWR mailing list s...@caver.net http://lists.caver.net/cgi-bin/mailman/listinfo/swr _______________________________________________ This list is provided free as a courtesy of CAVERNET. Remember when you are replying to a message, you are replying to ALL on this list. This a default setting. If you want to reply to the individual sender then click reply, go delete the name out of the To: field and insert who you want to reply to. Of course, you have to know the email address of the person you are wanting to reply to.
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