From: Megan Mansell Williams & Kathleen M. Wong, California Academy of Sciences
Published September 23, 2004 12:00 AM

Owls Use Dung to Fish for Beetles and Other Stories

Owls Use Dung to Fish for Beetles


Owls are tool-users, a new study finds. Douglas Levey and his colleaguesat the University of Florida in Gainesville suspected burrowing owls (Athenecuniculari) of collecting dung to lure in their favorite food: dung beetles. After all, their front stoops were coated in the feces of local mammals, andthe owls' own droppings were full of beetle parts.


But to test theirhypothesis, the researchers cleared the underground nests and surroundingareas of all foul traces, replacing fresh waste at some while leaving othersbare. By comparing owl diets over a four-day period, Levey and his teamfound that owls with dung-covered doorsteps ate 10 times more dung beetlesthan those with more sanitary digs, suggesting the pile-ups are no accident.


Their research, reported in the journal Nature, is the first study toquantify the advantages of tools use in wild animals. But calling owls wisebased on these results would be an overstatement. The swivel-necked birds ofprey probably aren't consciously baiting beetles. More likely, theirbehavior represents an adaptive trait that evolved via natural selection.


Parrots' Speech in Tongues


ADVERTISEMENT

Parrots can mimic human voices with startling accuracy. Now the mechanicsbehind their speech is being revealed. Gabriel Beckers of Leiden Universityin the Netherlands and colleagues knew that human speech consists of soundproduced in the voice box that is modulated by the throat, tongue, mouth, andnose. Flicks and rolls of the tongue can rapidly shift these tones further.


To see if the technique holds true for parrots, the researchers studiedSouth American monk parakeets killed as part of a program to rid theinvasive species from Florida. They inserted tiny speakers into the lifelessbirds to produce sound, then moved the birds' tongues ever so slightly assound reached their mouths.


In the journal Current Biology, the team reportsthat even tongue motions of less than a millimeter altered vocalfrequencies. In some cases, the shift was even more substantial than thedifference between English-speakers pronouncing an "A" versus an "O." Whetherlive parakeets use their tongues to adapt their voices remains to be seen,but the findings suggest good mimics may require similar equipment.


Signals from ET


Radio signals picked up on three separate occasions from the same area ofthe sky could be a signal from alien life, scientists say. The Search forExtraterrestrial Intelligence Institute (SETI) in Mountain View, California,scans the universe for patterned radio waves coming from unknown sources.Now, after six years of searching, the Institute says it may have found alive one.


The weak signal, collected three times by the Arecibo radiotelescope in Puerto Rico last year, comes from somewhere between theconstellations of Pisces and Aries. The signal was emitted at a frequencysome call extraterrestrial-friendly; the most common element in theuniverse, hydrogen, absorbs and gives off energy at the same frequency.


But this promising lead was observed for only a total of one minute. And somescientists think the alien-hunters are looking for an intergalactic messagein the wrong place. A new report in the journal Nature posits that we shouldexpect physical objects — the equivalent of a message in a bottle — fromaliens, not radio waves. Slow-moving but solid objects can hold moreinformation, and their data doesn't weaken or diminish with distance. Fornow, though, SETI is still scanning the airwaves.


Related Links


Owls Use Dung to Fish for Beetles: Nature News / National Geographic / Scientific American
Parrots' Speech in Tongues: New Scientist
Signals from ET: New York Times / National Geographic / New Scientist


Source: California Academy of Sciences


Terms of Use | Privacy Policy

2014©. Copyright Environmental News Network