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FEATURE

Patagonia has long attracted theattention of naturalists from allparts of the globe. Yet thisremote region, which includesthe planet’s southernmostwetlands and grasslands, stillholds many of the naturalworld’s mysteries.

In 1974, Mauricio Rumboll,a remarkable Argentineannaturalist, took part in one ofthe great discoveries thatPatagonia yields from time totime. He was immenselysurprised when one of hisstudents brought to his attentiona grebe that he soon realisedwas new to science. It was anoutstanding discovery, all themore surprising when weconsider that the Hooded GrebePodiceps gallardoi is a ratherconspicuous and large bird,about half a kilogram in weight,with colourful plumage, adistinctive voice and anattractive breeding display.

The emerging conservationgroups in Argentina reacted

quickly through FundaciónVida Silvestre Argentina(FVSA, the Wildlife Foundationof Argentina) by creating aprivate reserve at LosEscarchados lagoon, where thegrebe was discovered, about 150km east of the well knownPerito Moreno Glacier (LosGlaciares National Park).

At first, only some 250Hooded Grebes were thought toexist; the species was consideredthe rarest bird in the country. Inthe subsequent two decades, athorough survey of the plateausof Santa Cruz province wasundertaken and the estimatedgrebe population was believedto be 3,000–5,000. This wasprobably a considerableunderestimate, given thetechnological limitations offieldwork in those days. In 1994,it was downlisted fromThreatened to Near Threatenedon the IUCN Red List.

During the breedingseason, the grebe occurs solely

on the high plateaus east of theAndes. It breeds on a fewbasaltic lakes in the interior ofSanta Cruz, extreme south-westArgentina, with only occasionaland poorly documentedrecords from near Torres delPaine, in Magallanes, southernChile.

In winter, the speciesundertakes an extraordinaryjourney. When the high plateaulakes are frozen, the majority ofthe population moves to theAtlantic coast of Santa Cruzprovince, crossing thePatagonian steppe. The onlyknown wintering grounds arethe río Santa Cruz, Coyle andGallegos estuaries. The grebesmigrate at night, making theirmovements hard to track, sothe mystery of where they wentin winter was not solved until1994. But the whereabouts ofthe immature birds during thisharsh season and theirmigration routes, remain a bigunknown.

Collecting field data on thespecies is harsh to say the least,given the inhospitable habitat itlives in, the ferocity of theweather, the poor accessibilityand the huge distances to becovered. The plateau lakes arechecked by researchers in 4WDvehicles, on horseback, or evenon foot. The researchers goequipped with clothing andcamping gear designed for highmountain expeditions.

After the winter discoveriesof 1994, a period of silence andcalm followed. The assumptionwas that the grebe was safe,given its numbers and theremoteness of its habitat.Almost a decade went by. Then,news of the very low numbersfound in winter counts by theAsociación Ambiente Sur (AS),based in Santa Cruz, was pickedup by BirdLife Partner AvesArgentinas (AA).

In 2009, a team ofnaturalists and technicians fromAS and AA surveyed the most

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relevant plateau lakes over threeweeks, counting grebes andattempting to locate breedingcolonies. The outcome wasdisheartening: many of the lakeswere dry or becoming cloggedwith silt as a result of the generaldesertification of the region,leading to changes in thecomposition of the water. Waterlevels at known breeding siteswere 2–3 m lower than inprevious years.

Climate change might be amajor threat to this species andits habitat: anecdotal reportssuggest that recent wintersnowfall has been much reduced,without a correspondingincrease in precipitation at othertimes. Strong winds have causedaround 50% of all breedingattempts in the last three years(2009–2011) to fail. Recentinvestigations indicate that windgusts have significantly increasedin recent decades. At other timesthis threat would be marginal;with adult mortality naturally

very low, the species may beadapted to survive a successionof poor breeding seasons. But,with numbers falling so rapidly,the loss of entire breedingcolonies to wind damage couldhave a significant impact.

Counts on the winteringgrounds suggested a decline of40% over seven years. Surveysconducted in December 2006and January 2009, whichrevisited key known breedingsites surveyed in 1987 and 1998,also found sharp declines.Numbers fell from 452 to 51 atLaguna del Sello. Laguna delIslote, Tolderia Grande andLagunas Encadenadas, (700, 90and 198 individuals repectivelyin previous counts), no HoodedGrebes were found. The specieswas uplisted from NearThreatened to Endangered in2009.

The situation has worsenedsince then: data obtained in thelast three seasons point to aclear reduction in the estimated

population, perhaps close to80%, when compared to thatrecorded in the 1980s. In the1980s an average of 2,500individuals were found at the 78most important lakes, but in2010/11 only 400 were detected,despite surveying most of those78 lakes and around 120 otherlakes.

While there is speculationthat numbers fluctuatedramatically at breeding sitesfrom year to year, driven bymovements rather than actualpopulation fluctuations, theoverall declines detected on thewintering and breeding groundsappeared to be real and rapid.

“Our teams started to beworried when we realised thatthere was more than one causeto tackle if we were to conservethe grebe”, said Gustavo Costa,President of Aves Argentinas.

In many of the lakes in thegrebe’s core distribution, exotictrout were being introduced.“Trout rearing has reached the

most isolated places. Thisindustry is threatening not onlythe future of the grebe but alsothe rest of the wildlife present inthose environments”, GustavoCosta added. Also evident arethe increasing numbers of KelpGull Larus dominicanus, aknown predator of the grebe thathas benefited both from the fishindustry and from poor wastemanagement at humansettlements.

As if these problems werenot enough to push an alreadystruggling species over the edge,a breeding colony which AA andAS were studying in March 2011was devastated by another pestthat is advancing in westernPatagonia: the American MinkNeovison vison. Over 30 breedingadults were killed, and over 40eggs abandoned.

“This was a sad day, but atleast it meant that we haddiscovered one other reason forits decline—and a veryfrightening one at that—that

Hooded Grebe was onlydiscovered in 1974

(Diego Punta Fernandez)

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18 WorldBirdwatch

Hooded Grebe: the next member of the ‘extinct grebes club’?

could allow us to implementsuitable management actions inthe field”, said Gustavo Costa.

Members of the researchteam in 2010 also observedHooded Grebes nests beingrobbed by Black-necked SwanCygnus melancoryphus,behaviour which had not beenpreviously recorded and whichmay indicate that environmentalchanges are leading to increasesin interspecific competition.

A stark shadow was castover Aves Argentinas’s findingswhen, in May 2010, AlaotraGrebe Tachybaptus rufolavatusof Madagascar was declaredextinct; this was the third knowngrebe extinction since the lastquarter of the 20th century,after Colombian GrebePodiceps andinus and AtitlanGrebe Podilymbus gigas. Thisfollowed news that the CriticallyEndangered Junín GrebePodiceps taczanowskii, whichalready had a population of

fewer than 250 individuals, hadsuffered a further populationdecline.

“This is why we aredeveloping an action plan forthe Hooded Grebe, that involvesresearch, pest control andadvocacy at every level”, saidDr Andrés Bosso, Director ofthe International CooperationProgramme of Aves Argentinas.The meeting to develop thespecies action plan took place atAves Argentinas’s headquarters,in July 2009, bringing togetherspecialists from Ambiente Sur,Aves Argentinas, andFundacion Vida SilvestreArgentina.

“We need to strengthen theprotected areas system in theregion”, Andrés Bosso added.“Eight Important Bird Areas(IBAs) contain the species, butonly one is fully protected.”The site where the species wasdiscovered in 1974, Laguna LosEscarchados, was declared a

reserve in 1979, but is nowknown to hold only a marginalpopulation. Six individuals wererecorded within Perito MorenoNational Park, Argentina in1992. Key breeding lakes in thecore of the grebe’s range lack anykind of legal protection, but thepopulation stronghold onMeseta de Strobel is affordedsome protection by itsremoteness and inaccessibility.

“Thanks to support from theAV Jensen Foundation, we areprioritising Lago Buenos Airesplateau”, says Fabián Rabuffetti,Director of Conservation at AvesArgentinas. “This site should bedeclared a Ramsar site (awetland of internationalimportance) and there areopportunities to create a nationalpark in this area.” Among thetargets of the action plan isadvocacy at a national level forthe creation of a Hooded GrebeNational Park.

The wild territories inhabitedby Hooded Grebe also harbour avast number of animal and plantrarities, including endemic and/or undescribed lizards. They areimportant for populations ofrestricted-range birds whichoccur only in the SouthernPatagonia Endemic Bird Area.Significant percentages of theworld population of migrantNearctic shorebirds such asBaird’s Sandpiper Calidris bairdiiand Wilson’s PhalaropeSteganopus tricolor use thesewetlands as wintering habitat.Finally, cultural artefacts such aspetroglyphs and rock paintingsdating as far back as 10,000years are abundant on manysheltered rock faces overlookingthe lakes used by the birds.

“This is a fascinating andcomplex scenario. Its destinydepends massively on urgentconcrete conservation actions toensure the existence of its mostsignificant jewel, the HoodedGrebe,” said Gustavo Costa. “Ifwe were not to act accordingly,the future decade could witnessthe disappearance of aPatagonian symbol and abeautiful representative of thisattractive avian family. We havejust enough time to avoid this

incredible ‘new’ speciesfluttering to the same fate as theAlaotra Grebe, the ColombianGrebe and the Atitlan Grebe.Several key organisations areinvesting in this. They need ourhelp.”

Aves Argentinas is seekingfunding for a range of actions toensure the survival of theHooded Grebe, includingimplementation of summer andwinter surveys in 2012, 2013 and2014, embracing the entirety ofthe Buenos Aires, Asador, LasVizcachas, Viedma, Cardiel andStrobel plateaus, the Coyle andGallegos estuaries, as well asany of the plateaus reachable inwinter. Surveys will also becarried out on previouslyunsearched plateaus.

On the ground, conservationagents will be assigned to thespecies’ breeding and winteringgrounds during 2012, 2013 and2014, to execute a monitoringplan and implementconservation measures.

There will be a programmeto eradicate mink, to controlKelp Gull numbers on thebreeding grounds and to protectbreeding sites from strongwinds. Local farm workers willbe encouraged to become‘Guardians of the HoodedGrebe’, monitoring the presenceor absence of the birds, andgiving early warnings ofpotential new threats to thespecies. The conservationistswill seek agreements withlandowners on the plateaus andpurchase and protect propertiesas private reserves.

Ringing/banding andsatellite tracking will be used toimprove knowledge of thebirds’ movements and todetermine where juvenileHooded Grebes spend thewinter. Simultaneously, therewill be a campaign to raiseawareness of Hooded Grebeamong the people of Argentinaand to have the bird declared aNational Monument.

By Hernán Casañas,Santiago Imberti and

Ignacio Roesler

ABOVE Surveying Hooded Grebes requires working in very remote areas(Diego Punta Fernandez)

BELOW Introduced American Mink killed over 30 breeding adults in March(Ignacio Roesler)

WB

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HOODED GREBE APPEAL

In early 2011, thirtybreeding adult HoodedGrebes were killed byintroduced AmericanMink. Forty eggs werealso abandoned. Thisloss is unsustainable forthe species.

Urgent funds areneeded now toimplement the measuresneeded to protectgrebes this comingbreeding season. Weneed your help toprevent this happeningagain. Please supportthe BirdLife PreventingExtinctions Programmeand its work for HoodedGrebe.

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