Cli­mate change puts the bite on pen­guins

Weekend Argus (Saturday Edition) - - GOODPOSTER - JBJ RE­PORTER

PEN­GUINS are the cud­dly faces of the South­ern Hemi­sphere and among the most recog­nis­able birds to brave the chilly South­ern Ocean.

But ike so many other favourites of the an­i­mal king­dom – es­pe­cially those that in­habit the world’s cold­est places – they’re start­ing to suf­fer the ef­fects of cli­mate change.

The king pen­guin, an iconic black, white and yel­low bird sec­ond only in size to the em­peror pen­guin, is among the lat­est species to feel the heat.

King pen­guins raise their chicks on the sub- Antarc­tic is­lands north of Antarc­tica and dive for fish in the frigid wa­ters at the north­ern reaches of the South­ern Ocean. But their breed­ing and foraging be­hav­iours may be at risk as ocean tem­per­a­tures rise in the south­ern hemi­sphere.

New re­search shows that warmer sea-sur­face tem­per­a­ture can cause changes in the ma­rine en­vi­ron­ment where they feed, forc­ing the birds to travel far­ther and dive deeper for their food – and caus­ing de­crease in their pop­u­la­tions.

Cli­mate of the south­ern In­dian and At­lantic oceans de­pend on sev­eral fac­tors.

These in­clude the in­flu­ences of El Niño and La Niña, which cause phases of warmer and cooler tem­per­a­tures, as well as changes in at­mo­spheric con­di­tions in the south­ern hemi­sphere.

This can cause sea-sur­face tem­per­a­tures to rise and fall from one year to the next.

These tem­per­a­ture changes can change ma­rine ecosys­tems by driv­ing fish and other or­gan­isms into dif­fer­ent re­gions.

King pen­guins typ­i­cally for­age for food in an area of the South­ern Ocean known as the Antarc­tic po­lar front, a re­gion where the colder wa­ter in the south meets the warmer wa­ter to the north and draws an abun­dance of plank­ton, krill and fish.

In some years, though, if sea­sur­face tem­per­a­tures in the north­ern part of the South­ern Ocean get too warm, the po­lar front can be pushed south­ward.

This means king pen­guins have to travel far­ther from their is­land homes to get to the best feed­ing ar­eas.

The re­search says hav­ing to travel so much far­ther on foraging trips could have dam­ag­ing ef­fects on the king pen­guin pop­u­la­tion.

Re­searchers Charles Bost of the Chize Cen­tre for Bi­o­log­i­cal Stud­ies at the French Na­tional Cen­tre for Sci­en­tific Re­search, tracked the foraging pat­terns of king pen­guins liv­ing on the Crozet ar­chi­pel­ago in the south­ern In­dian Ocean be­tween 1992 and 2010.

They wanted to find out how sea-sur­face tem­per­a­ture changes might af­fect the birds’ foraging be­hav­iour, and whether changes in their be­hav­iour could also af­fect their pop­u­la­tion sizes and breed­ing.

The re­searchers found that in warm years, the Antarc­tic po­lar front shifted south forc­ing the pen­guins to travel far­ther to get to their prime feed­ing grounds.

This is a prob­lem for the birds dur­ing breed­ing sea­son, when pen­guin par­ents take turns in­cu­bat­ing eggs and rais­ing chicks and must travel back and forth be­tween the is­lands and the po­lar front much more of­ten to re­lieve their part­ners of par­ent­ing du­ties.

It is time- con­sum­ing and ex­haust­ing.

In 1997, the south­ern In­dian Ocean ex­pe­ri­enced an un­usual El Niño-driven warm­ing event.

The re­searchers ob­served that they also dove about 30m deeper for their food in this year com­pared with other years.

Many pen­guins did not sur­vive these ex­treme con­di­tions.

This is wor­ry­ing news, be­cause the king pen­guins won’t be the only species af­fected; seabirds or seals, will likely also be af­fected.

KID KING: A King pen­guin chick at The Aquar­ium at Moody Gar­dens in Galve­ston, Texas.

EN­DAN­GERED: King pen­guins are threat­ened by global warm­ing, which is cut­ting down their food sup­ply.

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