Iguanas from the sky: volunteers helping to conserve the Galapagos

Imagine a computer, an internet connection, and the desire to contribute to science. Now imagine all of this transforming into invaluable data that can be used to protect a unique animal species on the list of vulnerable species: the marine iguanas of the Galapagos Islands. This scenario is possible thanks to citizen science.

This is a participatory methodology that leverages the collaboration of a non-expert audience to collect, analyze, and interpret scientific data. Through online platforms, thousands of volunteers, who require no specific prior training and only a sincere desire to contribute to science, can participate in tasks as diverse as identifying galaxies, monitoring bees, or, in this specific case, counting marine iguanas. The image is powerful: scientists and citizens working together in real time, driven by a shared passion for knowledge and the protection of biodiversity.

The only marine reptile

Marine iguanas (Amblyrhynchus cristatus) constitute an exceptional evolutionary case. They are exclusive to the Galapagos: if they get lost, they disappear from the planet forever. They are the only reptile that inhabits and evolves in the marine ecosystem. They have adapted to swim and feed on algae while submerged, in cold, choppy waters, often with strong ocean currents. Being cold-blooded animals, or poikilotherms in scientific terminology (meaning they cannot regulate their body temperature like mammals and birds do), when they dive they constrict their peripheral blood vessels. This vasoconstriction prevents them from losing too much body heat, and to recover it, they then spend hours sunbathing perched on the rocks of their colony. They swim using their tails and excrete the excess salt they ingest when feeding on algae by making a saline sneeze—exhaling salt under pressure through their nose as if sneezing.

There are eleven distinct subspecies of marine iguanas, each adapted to a specific microenvironment. They can measure over a meter in length and weigh up to ten or twelve kilograms, depending on the subspecies and whether they are male or female. They form complex social structures and live on volcanic rock cliffs, often inaccessible from the ground. However, their survival is threatened by the presence of invasive species, such as dogs, cats, rats, and rabbits, and by pollution, climate change, and habitat loss due to unregulated human activities.

Drones for conservation

This is where the Iguanas from Above project comes in. Led by the University of Leipzig, Germany, it uses drones to fly over the rocky coast of the Galapagos Islands and capture high-resolution images of marine iguana colonies. Unlike traditional tracking, which is expensive, laborious, often invasive, and in many areas nearly impossible, this strategy allows for the involvement of volunteers from around the world eager to contribute to citizen science. Before this project began in 2019, there was no reliable data on the number and distribution of nine of the eleven marine iguana subspecies in the Galapagos.

Photographs taken by drones in a non-intrusive manner are posted on a platform called Zooniverse, which was born in 2009 from a project to classify galaxies also through citizen science. Volunteers then view the photographs, marking the iguanas they see, along with other parameters of interest, such as the presence of floating plastics, which pose a threat to their survival. Each image receives multiple views, an average of 30, to ensure the reliability of the counts with the majority vote of the volunteers.

This isn't the only case of citizen science applied to bioconservation. There are other equally successful projects, such as the Condor Watch project on vultures, the Bat Detective project on bats, and the Plankton Portal project on marine plankton: thousands of labeled images have made it possible to identify endangered species, ecosystem changes, and biodiversity gains or losses.

Know to conserve

The results are convincing. With the participation of 13,000 volunteers who analyzed nearly 1.5 million photographs, not only has a count been made of the iguanas on the different islands of the archipelago, but the most vulnerable colonies and the reasons for their vulnerability have been identified, allowing for the planning of conservation actions specifically targeted at each collection. These actions include: pollutants, measures against invasive species, navigation restrictions, and protection and awareness campaigns.

Experts oversee and validate the entire process, but the collective effort of volunteers is its true driving force. Without them, the scientists involved in this project or so many other citizen science projects would never be able to process so many frames quickly enough. Citizen science, far from being a fad, is a necessity in the new ecology of knowledge, which allows for the acceleration and democratization of scientific research.