Last January, the Natural Processes Monitoring Team (ICTS-RBD) of the Doñana Biological Station carried out the International Waterbird Census during winter in the Guadalquivir Marshes (Doñana Natural Space, adjacent unprotected areas and Brazo del Este Natural Site), coordinated by Wetlands International. The total estimated number of birds registered was around 532 thousand, belonging to 91 different species.

Waterbird communities are potential indicators of ecological changes in threatened wetland ecosystems and a potential object of ecological monitoring programs. Waterbirds often breed in largely inaccessible colonies in flooded habitats, so unmanned aerial vehicle (UAV) surveys provide a robust method for estimating their breeding population size. In this study the main breeding colony of Glossy ibis (Plegadis falcinellus) at the Doñana National Park was surveyed.