Mother Na­ture los­ing her tim­ing: study


Lethbridge Herald - - HEADLINE NEWS - Bob We­ber THE CANA­DIAN PRESS

Mother Na­ture is los­ing her tim­ing. A ma­jor study has con­cluded that the del­i­cately chore­ographed in­ter­ac­tions be­tween species that keep food webs func­tion­ing are more and more out of synch. And while the pa­per isn’t con­clu­sive, it casts a sus­pi­cious eye on cli­mate change.

“Ev­ery­thing is con­sis­tent with the fact it’s get­ting warmer,” said Heather Kharouba, a Uni­ver­sity of Ot­tawa ecol­o­gist and lead au­thor of a pa­per pub­lished Mon­day in the jour­nal Pro­ceed­ings of the Na­tional Academy of Sciences.

Sci­en­tists have been find­ing for years that events in the nat­u­ral world aren’t quite lin­ing up the way they used to.

Cari­bou calves are born later dur­ing the thick of black­fly sea­son. Mi­grat­ing hum­ming­birds, adapted for a spe­cific spring flower, miss its bloom. Se­abirds no longer rear their chicks when fish are most abun­dant.

“Most of the ex­am­ples were about food,” said Kharouba. “Is it avail­able or is it not?”

Kharouba and her col­leagues de­cided to find out if the phe­nom­e­non was wide­spread and if they could mea­sure it.

Min­ing pre­vi­ous re­search from 1951 to 2013, they ex­am­ined 88 species of mam­mals, birds and fish from four con­ti­nents. The data in­cluded 54 dif­fer­ent re­la­tion­ships in­volv­ing preda­tors and prey, plant eaters, pol­li­na­tors and com­peti­tors.

The team found that, as the cli­mate has warmed, events in those re­la­tion­ships have been oc­cur­ring an av­er­age of four days ear­lier per decade since the early 1980s — about 14 days in to­tal.

Not all are chang­ing at the same rate, though.

Some are closer to­gether; some are fur­ther apart. The split is about 50-50. The rel­a­tive tim­ing of the events be­tween species is now, on av­er­age, off by about 21 days.

“It leads to a mis­match,” Kharouba said. “These events are out of synch.”

She said time spanned by the data was too short to prove the mis­matches were caused by cli­mate change. The cor­re­la­tion, how­ever, was strong.

“We think it is the case,” she said. “All the changes we see are ex­actly what we would pre­dict with warmer tem­per­a­tures and how we would ex­pect bi­ol­ogy to re­spond.”

The con­se­quences are sim­i­larly hard to pre­dict, but po­ten­tially far-reach­ing.

Mis­matches at the bot­tom of the food chain could re­duce re­sources all the way up, Kharouba said. One study in a lake found the tim­ing of blooms for the one­celled plants and an­i­mals that un­der­lie aquatic life is off by 34 days.

Con­ser­va­tion man­agers look­ing af­ter en­dan­gered species may have to start tak­ing en­vi­ron­men­tal mis­matches into ac­count, the ecol­o­gist sug­gested.

As­so­ci­ated Press photo

A guille­mot seabird sits on the beach of Cava­lier in An­glet, south­west­ern France in this 2014 file photo. A ma­jor new study has con­cluded that the del­i­cately chore­ographed in­ter­ac­tions be­tween species that keep food webs func­tion­ing are more and more...

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