Mapping the mysterious migration route of the Critically Endangered Hooded Grebe

Locations: Santa Cruz province, Patagonia, Argentina
Active dates: 2017 - ongoing

Aims

We will track the Hooded Grebes migration route from the lakes high on the plateaus down to the estuaries on the coast. The route is currently unknown and detailed information about its migration movements is crucial to predict the impact of hydroelectric dams that are planned in the area. With the support of the Erasmus Darwin Barlow fund, this project is also building capacity for conservation by supporting two early career conservationists to join the expedition.

Species

Hooded Grebe

Background

The hooded grebe (Podiceps gallardoi) was only discovered 43 years ago, but during this time there has been an estimated 80% reduction in its population. There are now though to be less than 400 breeding pairs. It has captivating crimson eyes and one of the most spectacular mating displays in the world - reminiscent of the Argentinian Tango.

During the Patagonian summer, from November to April, the grebe breeds in lakes and lagoons of the highland plateaus in the west of the Santa Cruz province. During autumn (April), the birds migrate to the river estuaries of Argentina’s Atlantic coast, primarily the Santa Cruz River estuary.

In the plateau lakes, the grebe faces many threats. Predation by the invasive America mink (Neovision vison) and native kelp gull (Larus dominicanus) can cause large numbers of deaths in a short period of time. The introduced rainbow trout (Oncorhyncus mykiss), competes with the grebe for food and alters the environmental characteristics of the lakes where the Grebe breeds. Climate change is having a major negative impact, as reduced snow fall is causing the lakes to dry up and stronger winds can destroy nests. In 2009, Aves Argentinas and Ambiente Sur teamed up to stabilize the population by safeguarding the breeding subpopulations and mitigating the threats from introduced species. Dedicated work from the Hooded Grebe project team has managed to greatly reduce the number of deaths from the mink, gulls and trout.

However, new threats are emerging. Two hydroelectric power stations are proposed for the Santa Cruz river, the last remaining glacial river in Patagonia and the main estuary the grebe relies upon. As the migration route of the grebe is unknown, it is very difficult to predict the impact of the dams and plan how best to mitigate the negative impact they will have. A detailed map of the migration route is urgently needed to identify key refuges on the route and the species key winter strongholds. This is a crucial next step for mitigating all of the grebe’s threats throughout its migration, thus safeguarding its long-term survival.

The EDGE of Existence team has been working with the Hooded Grebe Project (Maca Tobiano Proyecto) team in Patagonia to identify GPS tags that are suitable for this small bird, which weighs less than 500g. This year, the Erasmus Darwin Barlow fund is also supporting this important work and enabling two early career conservationists from the UK to join the expedition with the the EDGE of Existence Conservation Biologist, Claudia Gray. This project will therefore enable knowledge exchange between conservationists in Argentina and the UK, reinforcing international collaborations and building capacity to save this unique and stunning bird.

Actions

- one scientist from EDGE (Dr Claudia Gray) and the two 2018 Erasmus Darwin Barlow awardees (Sarah Gluszek and Thomas Mackay Smith) will visit the study site for two weeks in March 2018
- fit GPS transmitters to 6 birds and monitor the trackers’ durability and success at logging the birds’ movements
- develop and pilot social research methods to find out more about local attitudes towards the dam and the grebes
- undertake a knowledge exchange day between the visiting EDGE scientists and the team in Patagonia