Study: Wind farm ‘preda­tor’ harms birds

The Phnom Penh Post - - WORLD -

WIND farms act as a top “preda­tor” in some ecosys­tems, harm­ing birds at the top of the food chain and trig­ger­ing a knock-on ef­fect over­looked by green en­ergy ad­vo­cates, sci­en­tists said on Mon­day.

Wind is the fastest-grow­ing re­new­able en­ergy sec­tor, sup­ply­ing around four per cent of global elec­tric­ity de­mand.

Close to 17 mil­lion hectares – an area roughly the size of Tu­nisia – is cur­rently used for gen­er­at­ing wind en­ergy world­wide, and re­searchers warned that de­vel­op­ers had “greatly un­der­es­ti­mated” the im­pact the tech­nol­ogy has on wildlife.

In new re­sea rch, a n in­ter­nat iona l tea m of sci­ent ist s st ud­ied t he ef fects of wind t urbi ne use i n t he Wester n Ghats, a Unesco-listed range of moun­tains and forest span- ning In­dia’s west coast re­gion a nd a g loba l “hot spot ” of bio­di­ver­sit y.

They found that preda­tory rap­tor birds were four times rarer in ar­eas of plateau where wind tur­bines were pre­sent, a dis­rup­tion that cas­caded down the food chain and rad­i­cally al­tered the den­sity and be­hav­iour of the birds’ prey.

In par t i cu­lar, the team ob­served an ex­plo­sion in the rap­tors’ favourite meal, fan­throated lizards, in ar­eas dom­i­nated by the tur­bines.

Fur­ther­more, they saw sign i f ic a nt cha nges i n l i z a rd be­hav iour a nd ap­pea ra nce, l i v i ng a s t hey were i n a n e s s e nt i a l l y pr e d a t or-f r e e env iron­ment.

“What was re­mark­able to us were the sub­tle changes in be­hav­iour, mor­phol­ogy, and phys­i­ol­ogy of those lizards,” said Maria Thaker, as­sis­tant pro­fes­sor at the In­dian In­sti­tute of Sci­ence’s Cen­tre for Eco­log­i­cal Sciences and lead study author.

As the lev­els of rap­tors fell around the tur­bines, so too did the rate of preda­tory at­tacks the lizards had to deal with.

As a re­sult, the team found that lizards liv­ing in and around wind farms had less­ened their vig­i­lance against pos­si­ble dan­ger.

S i m u l a t i n g “p r e d a t o r at­tacks”, hu­mans in the study could get up to five times closer to a lizard in the wind farm zones than one liv­ing away from the tur­bines be­fore the crea­tures fled.

Af­ter test­ing, the lizards near wind­mills were found to have lower lev­els of a stress hor- mone, some­thing that must have emerged in the two decades since wind farms were built in the Western Ghats.

Wind farms are known to be harm­ful to birds, dis­rupt­ing their mi­gra­tion pat­terns and caus­ing above av­er­age death rates.

Thaker said her re­search, pub­lished in the jour­nal Na­ture Ecol­ogy & Evo­lu­tion, showed that wind farms repli­cated the role of the top preda­tor in the food chain by keep­ing the rap­tors at bay.

“They trig­ger changes to the bal­ance of an­i­mals in an ecosys­tem as if they were top predators,” she said.

“They are the ‘predators’ of rap­tors – not in the sense of killing them, but by re­duc­ing the pres­ence of rap­tors in those ar­eas.”

As man­made car­bon emis­sions con­tinue to rise, Thaker said wind en­ergy was vi­tal in mit­i­gat­ing the ef­fects of cli­mate change.

But with ev idence that the im­pact of wind farms reaches f ur t her i nto Ea r t h’s ecosys­tems than pre­vi­ously thought, she ca lled for greater con­sid­er­a­tion of the env iron­men­tal i mpact of t he v it a l g re en en­erg y source.

“It took decades for sci­en­tists to re­alise that wind tur­bines were neg­a­tively af­fect­ing an­i­mals that fly,” Thaker said.

“We need to be smart about how we de­ploy green en­ergy so­lu­tions.

“Let’s re­duce our foot­print on the planet and put tur­bines in places that are al­ready dis­turbed in some way – on build­ings for ex­am­ple.”

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