7 Nov 2017

Meet the guardians watching over Argentina's threatened nesting sites

In Argentina, there are only 600 Saffron-cowled Blackbirds left, and nest predation is sabotaging their chances of population recovery. But this looks set to change thanks to the incredible dedication of Colony Guardians—2017 BirdLife Nature's Heroes—volunteers who camp out at the nesting sites to watch over the eggs and chicks.

Saffron-cowled Blackbird Conservation Project members scan the landscape to locate nesting sites © Francisco González Táboas
Saffron-cowled Blackbird Conservation Project members scan the landscape to locate nesting sites © Francisco González Táboas
By Inés Pereda & Francisco González Táboas, Aves Argentinas

In Argentina, the loss of our Pampas grass habitat is a huge threat to biodiversity. Agrochemicals, cattle trampling and the intentional burning of vegetation all spell disaster for national treasures like the Strange-tailed Tyrant Alectrurus risora and the Pampas Meadowlark Leistes defilippii. But the impact is even worse on species who are struggling to rear enough young to bounce back.

This is the case for the Saffron-cowled Blackbird Xanthopsar flavus. Classed as Vulnerable worldwide, the situation is even worse in Argentina, where the species is listed as Critically Endangered due to extremely rapid population declines. And the success of the few reproductive colonies left is being severely sabotaged by predation from foxes, reptiles and raptors. Not to mention the cuckoo-like brood parasitism of the Shiny Cowbird Molothrus bonariensis.


The Saffron-cowled Blackbird is Critically Endangered in Argentina due to habitat degradation © Inés Pereda


That’s why, after a highly successful campaign in 2015, Aves Argentinas (BirdLife partner) joined forces with charities and government bodies alike* to create the Saffron-cowled Blackbird Conservation Project.

Our aim is simple: every spring, we locate the reproductive colonies and nests scattered around the provinces of Entre Rios and Corrientes. Then we appoint Colony Guardians to watch over them, using an adaptation of the techniques used for the Hooded Grebe Project in the cold Patagonian plateaus.

But it’s not easy. Each breeding season starts with great uncertainty as to where the blackbirds are going to settle their nests. And searching every ranch and grassland is a difficult task when the crops and land uses change year by year. Every season we cover over 15,000 km in our quest along the provinces’ roads. However, after long hours of driving, perseverance and an extensive network of connected informants, we finally locate the colonies and their nests (which themselves are notoriously difficult to spot).


A Saffron-cowled Blackbird nest and chicks © Inés Pereda


Our biggest asset at this stage is our dedicated community of land owners, farm workers, birdwatching clubs, provincial park rangers and members of Grasslands Alliance (Alianza del Pastizal), all poised for a flash of yellow and black plumage.

Once the colonies are found, we call in our heroic volunteer Colony Guardians to watch over the nests and fledglings and drive predators and parasites away. We erect special exclusion nets which bar the way of snakes, raptors and mammals while allowing the Saffron-cowled Blackbird free access. Our presence also deters potential illegal bird poachers and traffickers. And while protecting the nests, we can study the ecology and reproductive biology of this fascinating and globally threatened species.


Colony Guardians check up on a nest protected by a predator exclusion net © Inés Pereda


We monitor the development of the eggs and chicks with extreme care using camera traps and video recording devices. These cameras also help us to understand how the parents are adapting to our presence, how they care for their chicks, and which predators are the worst offenders.

Throughout the 2015 and 2016 breeding seasons, we located and monitored the success of 15 Saffron-cowled Blackbird reproductive colonies. We found that in protected nests, 69% of the offspring fledged successfully, whereas in unprotected nests the survival rate was only 36%. From this we can see that our presence really does significantly improve the breeding success of the Saffron-cowled Blackbird.


The development of the Saffron-cowled Blackbird chicks is monitored with the utmost care © Inés Pereda


The project is still in its early stages, so it is important to evaluate each step carefully. However, our initial results are looking very promising indeed. They suggest that the extra chicks we help to fledge will be enough to generate urgently-needed population growth when they reproduce the following season

Year by year, the project is gathering strength thanks to the provincial governments, researchers, volunteers and members dedicated to the conservation of this beautiful bird. In fact, this year our volunteers and local birdwatchers were presented with a Nature’s Heroes Award by BirdLife International in recognition of their hard work protecting this species.

Next spring, we hope to locate even more new colonies, as well as recovering individuals we tagged last year. We also hope to expand our network further and hone our research and communication techniques. To continue our work and increase our capacity we need all the help we can get - but if the devotion and enthusiasm of our existing supporters is anything to go by, this achievement looks well within reach. 

If you would like to support our work with the Saffron-cowled Blackbird, you can donate directly to our project here. Alternatively, bid on one of our beautiful paintings of endangered birds to raise money for their conservation, or become an Aves Argentinas member.

*The project is made possible by the collaboration of the National Research Station and the Centre of Applied Ecology (CONICET) and ecoparque Interactivo de la Ciudad de Buenos Aires, together with local NGOs Aves Gualeguaychú, Reserva El Potrero and Tingazú Birding Club (COA), Fundación Azara and the support and resources of the provincial governments of Entre Rios (Dirección de Recursos Naturales) and Corrientes (Direccion de Recursos Naturales - Parques y Reservas), Entidad Binacional Yaciretá, The Rufford Foundation and Neotropical Grasslands Conservancy.