Birds evolve to dodge trafficSly swallows fly on little

wings, study finds

Does a new study offer a bird's-eyeiew into evolution?Fewer cliff swallows are being

illed by moving vehicles because ofvolution, says a study published todaythe journal Current Biology,"These birds have been exposed to

ehicles and roads for 30-plus years,"aid Charles Brown, the study's leaduthor. "During that time, they havevolved to avoid being killed by traffic.volution can happen very rapidly, andorne animals can adapt to urban envi-onments very rapidly."The decrease in road deaths is likely

ecause these birds have shorter wing-pans, making them more agile fliersr they are learning to avoid vehicles,rown said. .An estimated 80million birds are

illed by colliding with vehicles onU.S.oads each year, according to a 2005.S. Forest Service report. .In the western U.S., cliff swallows,hich live in colonies, have nestsound highway bridges, overpassesd road culverts. They sit on roads to·ck up gravel for their gizzards to help·gest food and to sunbathe.The road kill index decreased fromout 20 cliff swallows a year at theart of the study in 1983in Nebraska toestimated two birds a year. by the.

udy's end in 2012.' .This is only an estimate of thoseled because more died but were notund,The drop can't be explained by de-. es in the bird population or in traf-, the study suggests. The birds thatntinue to die on the roads have longer· gspans. Wing lengtbs vary between~--------~~~--------------~--~----~~~'-.----

By Cathy PayneUSA Today.

Cliffswallows sit at their nest inNebraska. The birds have become lesslikelyto get hit by cars, USA TODAY

WILY CRITTERSCharles Brown, the study's lead author, saidcliff swallows do learn from watching othersso some' may figure out how to avoid on-coming traffic. "Birds that have the ability tolearn are more likely to survive and producemore babies," he said. "Overtime, the pop-ulation will have smarter birds."

4.1 inches and 4.5 inches, Brown said."Longer-winged swallows sitting on

a road probably can't take off as quick-ly,or gain altitude as quickly as shorter-winged birds, and thus the former aremore likely to collide with an oncomingvehicle," said Brown, a professor ofbiological sciences at the University ofThlsa.

Geoff LeBaron, an ornithologistwith the National Audubon Society,says shorter wingspan would allowcliff swallows to turn more quickly toavoid being hit by vehicles. "If the long-er-winged birds are the ones beingclobbered, then the shorter-winged.birds are the ones passing on genes tothe next generation;" said LeBaron, thesociety's Christmas Bird Count direc-tor, who was not involved in the study.

The study also found that the aver-age wing length is shorter. In the 1980s,. the average was 4.3 inches; it droppedto 4.1 inches in the late 2000s, Brown'said.

Sim~n's.4-teens-only mallpolicy Isn't the solution

. T~e recent decision by the I ~.:~l~~Metropolitan Police Dep~rt~~ntgroup~~~~~~~~Z to~rUfe~~~reak upC.astlet~n ~quare Mall is ridicul~~~sa~ddI~~pPofmtmg.In a city. that offers nofo~IOns or teens to gather with theirrtends the m 11' h .th '. a ISt e only place withe ex~eptlOn of a school or a pla~e of

worshIp, th~t young people are able tomeet up. This new policy will alate an th . so ere-o er opportumty for prOfiling ofyoung people. Willmall security break~fr~~~~tPofbfivewell-behaved whitemall :will ~1e °bYSgO.toa I?ovie at the

, ey e split up into twor{~ffl~i~KLs~curityif they want to go tome.d The real issue that should be ad-

y~~~~~~~a~~~~~f;t~~~~,~i~~Se~~ft~r~ssue at the mall, more security guardsl·ho~ld be p~es~nt. A policy that further~I s o~ kIds. options for enjoyment

SO':I. setting and increases theprol;>abIlIty~f racial and gender profil-~~~~~~~l~g. There is a rational waythe mall I hIf1creased safety issues atJ

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F' - Ire more security.u Ie oreanCarmel

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