Biodiversity
Monitoring and surveys
Breeding terns in Aruba
Through many years of detailed research into breeding terns, Waardenburg Ecology has built a unique knowledge that is recognised worldwide. This was exactly what Utilities Aruba needed for gaining insights into the breeding ecology and movements of terns in Aruba.
20.000 breeding terns
Aruba hosts 15-30% of the world’s breeding population of Cayenne Tern, as well as breeding Cabot’s, Royal, Sooty, Bridled, Common, Roseate and Least terns, and Brown and Black noddies, totalling an estimated 20,000 individuals. However, as the most recent estimates and status of the island’s breeding terns date back to 2016, Waardenburg Ecology were invited to continue monitoring of breeding colonies and begin research to study their spatial ecology. This builds upon earlier research carried out between 1998 and 2016 by Adrian Delnevo, who initiated monitoring and training programmes in the region.
Essential insights into habitat en trackingstudies
During an initial visit in May 2026, our certified drone pilot and geo-ecological data expert Job de Jong, and ornithologist Mark Collier, visited Aruba to carry out drone surveys of four areas of the San Nicolas Bay Reef Islands and nearby coast. The images collected will be processed by our internally developed AI-software to identify and count breeding Cayenne and Cabot’s terns. These images also provide insights into the areas and habitats used by the terns as well as their breeding activity.
Estimates of other species that breed in or under vegetation, including Sooty and Bridled terns and Brown Noddy, will be supported by additional ground counts that were undertaken during colony visits. These visits also provided essential insights into breeding status, potential predation issues, and into the possibilities for future GPS-tracking studies in the next phase of the project. These planned GPS-tracking studies will help identify key foraging areas and breeding success of the terns, providing essential information to ensure the long-term protection of these species and their breeding habitats. Additional visits to the Parke Nacional Arikok supported by the Aruba Conservation Foundation (ACF) provided opportunities for identifying breeding areas for Least Terns in this windswept and rugged coastal landscape.
We are grateful for the support and contributions of all stakeholders including Aruba Conservation Foundation (ACF), Aruba BirdLife Conservation, Utilities Aruba N.V., Vogelbescherming Nederland en Water- en Energiebedrijf Aruba N.V. (WEB), without whom this fieldwork would not have been possible.
Estimates of other species that breed in or under vegetation, including Sooty and Bridled terns and Brown Noddy, will be supported by additional ground counts that were undertaken during colony visits. These visits also provided essential insights into breeding status, potential predation issues, and into the possibilities for future GPS-tracking studies in the next phase of the project. These planned GPS-tracking studies will help identify key foraging areas and breeding success of the terns, providing essential information to ensure the long-term protection of these species and their breeding habitats. Additional visits to the Parke Nacional Arikok supported by the Aruba Conservation Foundation (ACF) provided opportunities for identifying breeding areas for Least Terns in this windswept and rugged coastal landscape.
We are grateful for the support and contributions of all stakeholders including Aruba Conservation Foundation (ACF), Aruba BirdLife Conservation, Utilities Aruba N.V., Vogelbescherming Nederland en Water- en Energiebedrijf Aruba N.V. (WEB), without whom this fieldwork would not have been possible.