Inglkes
Páginas: 3 (576 palabras)
Publicado: 7 de mayo de 2012
WHALES HAVE SONAR "BEAM" FOR TARGETING PREY
Toothed whales target quickly moving prey with a constantly shifting, tightly focused sonar beam, a new study says.
All toothed whales and dolphinsecholocate, clicking loudly via special nasal structures and listening for echoes bouncing off objects. This skill is especially crucial in the dark ocean, where the mammals' vision is of little use.Newexperiments show that whales can focus their clicks into a type of sonar beam to efficiently track fast-moving prey.
"The bottom line is echolocation is how these animals make their living," said studyleader Laura Kloepper, a zoologist at the University of Hawaii in Honululu."Not only do they have to locate fish, they have to discriminate fish and figure out what kind of fish it is—it's this constantunderwater dance between predator and prey."It makes sense [that] of course there has to be focusing going on." (See "Killer Whales Target Favorite Fish With Sonar?")
Mischievous Whale
For theirexperiments, the team worked with Kina, a false killer whale at the University of Hawaii with decades of training—and a penchant for mischievously splashing Kloepper. "After a few days I learned to carryan umbrella to protect my equipment," Kloepper said. Kina "got a kick out of watching me scramble."
In the first experiment, a trainer instructed Kina to swim into an underwater hoop up to herpectoral fins. Then, a soundproof door lowered and she echolocated on a target—a hollow cylinder that looks like a toilet paper tube.Kina had previously been trained to recognize the thickness of thisparticular cylinder and to signal this by touching a button with her snout, which earned her a fish reward.
The whale was also trained to stay still when shown other cylinders of varyingthicknesses.Kloepper and colleagues then presented Kina with two other types of cylinders to test her echolocation skills: one with much thicker walls, which she could detect easily, and another with only slightly...
Toothed whales target quickly moving prey with a constantly shifting, tightly focused sonar beam, a new study says.
All toothed whales and dolphinsecholocate, clicking loudly via special nasal structures and listening for echoes bouncing off objects. This skill is especially crucial in the dark ocean, where the mammals' vision is of little use.Newexperiments show that whales can focus their clicks into a type of sonar beam to efficiently track fast-moving prey.
"The bottom line is echolocation is how these animals make their living," said studyleader Laura Kloepper, a zoologist at the University of Hawaii in Honululu."Not only do they have to locate fish, they have to discriminate fish and figure out what kind of fish it is—it's this constantunderwater dance between predator and prey."It makes sense [that] of course there has to be focusing going on." (See "Killer Whales Target Favorite Fish With Sonar?")
Mischievous Whale
For theirexperiments, the team worked with Kina, a false killer whale at the University of Hawaii with decades of training—and a penchant for mischievously splashing Kloepper. "After a few days I learned to carryan umbrella to protect my equipment," Kloepper said. Kina "got a kick out of watching me scramble."
In the first experiment, a trainer instructed Kina to swim into an underwater hoop up to herpectoral fins. Then, a soundproof door lowered and she echolocated on a target—a hollow cylinder that looks like a toilet paper tube.Kina had previously been trained to recognize the thickness of thisparticular cylinder and to signal this by touching a button with her snout, which earned her a fish reward.
The whale was also trained to stay still when shown other cylinders of varyingthicknesses.Kloepper and colleagues then presented Kina with two other types of cylinders to test her echolocation skills: one with much thicker walls, which she could detect easily, and another with only slightly...
Leer documento completo
Regístrate para leer el documento completo.