Recent surveys on its coastal Patagonian wintering grounds indicate that the Endangered Hooded Grebe Podiceps gallardoi has declined by 40% in the last seven years and this, along with alarming new threats detected on its breeding grounds during 2011, indicate action is now urgently required to prevent the rapidly increasing threat of its extinction.
In response to these worrying findings, Aves Argentinas (BirdLife in Argentina) has mounted a wide-ranging offensive to protect this highly-threatened migratory species from further decline. In support, we are launching an international online appeal through the BirdLife Preventing Extinctions Programme to help fund the urgently required conservation action that they have already begun.
Discovered only as recently as 1974, Hooded Grebe has declined by as much as 80% in the last 30 years and as a result of surveys conducted in 2006 and 2009, the species was uplisted by BirdLife to Endangered on the IUCN Red List in May 2009. Recent counts on the wintering grounds last year, suggest the decline is steepening further.
“Our teams started to become really worried when we realised that there was more than one cause to tackle if we were to conserve the Hooded Grebe”, said Gustavo Costa, President of Aves Argentinas.
In many of the lakes in the grebe’s core distribution, exotic trout have been introduced for industrial fish production. “Trout rearing has reached the most isolated places, and this industry is threatening not only the future of the grebe but also the rest of the wildlife present in those environments”, Gustavo Costa added. Also evident are the increasing numbers of Kelp Gull Larus dominicanus, a known predator of the grebe that has benefited from both the fish industry and poor waste management at human settlements.
As if these problems were not already enough to push this struggling species over the edge, a breeding colony which Aves Argentinas was studying at Laguna El Cervecero, Santa Cruz Province in March 2011, was devastated by a sinister and ferocious invasive pest that is now advancing in western Patagonia: the American mink, Neovison vison. More than 30 breeding adult Hooded Grebes were found killed by mink at this one site, and a further 40-plus eggs were abandoned.
“This was one of the saddest days in my life as a naturalist, but at least it meant that we had discovered another reason for the Hooded Grebe’s decline – and a very frightening one at that – that could allow us to implement suitable management actions in the field”, said Kini Roesler, a field biologist who is doing his PhD on the species.
As part of the immediate conservation action Aves Argentinas is coordinating, a team of scientists and conservationists including staff from Aves Argentinas, Ambiente Sur and CONICET are currently in the field attempting to prevent predation at several known colonies this breeding season. Measures to control mink and reduce predation by gulls are being prioritised and wherever breeding populations are located, they plan to set up ’round the clock’ watches to protect the nesting birds.
Climate change is also a major threat to this species and its habitat: anecdotal reports suggest that recent winter snowfall has been much reduced, without a corresponding increase in precipitation at other times. Many of the lakes surveyed last year were found to be dry or becoming clogged with silt as a result of the general desertification of the region, leading to changes in the composition of the water. Water levels at known breeding sites were 2-3 m lower than in previous years.
A stark shadow was cast over Aves Argentinas’s findings when, in May 2010, the Alaotra Grebe Tachybaptus rufolavatus of Madagascar was declared extinct. This was the third known grebe extinction since the last quarter of the 20th Century, after the Colombian Grebe Podiceps andinus and Atitlan Grebe Podilymbus gigas, and followed news that the Critically Endangered Junín Grebe Podiceps taczanowskii, which already had a population of fewer than 250 individuals, had suffered a further population decline.
“This is why we are developing an action plan for the Hooded Grebe, that involves research, pest control and advocacy at every level”, said Dr. Andrés Bosso, Director of Aves Argentinas’ International Co-operation Programme. An initial meeting to develop a species action plan took place at Aves Argentinas’s headquarters, in July 2009, and brought together specialists from Ambiente Sur, Aves Argentinas, and Fundacion Vida Silvestre Argentina who are now working closely together.
“We need to strengthen the protected areas system in the region”, Andrés Bosso added. “Eight Important Bird Areas (IBAs) contain the species, but only one is fully protected.” Laguna Los Escarchados, the site where Hooded Grebe was discovered in 1974, was declared a reserve in 1979, but is now known to only hold a marginal population. Key breeding lakes in the core of the grebe’s range lack any kind of legal protection, though the population stronghold on Meseta de Strobel is still afforded some protection by its remoteness and inaccessibility.
Aves Argentinas has been appointed official BirdLife Species Guardian for Hooded Grebe and is seeking funding for a range of urgent actions that are already in progress to ensure the survival of the species. These include implementation of summer and winter surveys and predator control in 2012, 2013 and 2014, embracing the entirety of the Buenos Aires, Asador, Las Vizcachas, Viedma, Cardiel and Strobel plateaus, the Coyle and Gallegos estuaries, and any of the plateaus reachable in winter. Surveys are also now being carried out on previously unsearched plateaus.
A number of local conservation agents are also being assigned to the species’ breeding and wintering grounds to execute a monitoring plan and implement the needed conservation measures.
The programme to eradicate mink, control Kelp Gull numbers on the breeding grounds, and help protect breeding sites from strong winds has already begun in earnest. Farm-workers will be encouraged to become local “Hooded Grebe Guardians”, monitoring the presence or absence of the birds, and give Aves Argentinas early warnings of potential new threats to the species. Conservationists are also seeking agreements with landowners on the plateaus to purchase and/or protect their properties as private reserves.
Ringing/banding and satellite tracking will be used to improve knowledge of the birds’ movements, and determine where juvenile Hooded Grebes spend the winter.