Photogrammetry as a tool for sex identification and sex ratio estimation in Chilean Flamingos

Understanding the demographic characteristics of animal populations, such as age, sex, and population structure, is essential for effective wildlife management and conservation. However, accurately identifying these traits in wild populations is challenging, especially for birds inhabiting remote or sensitive wetlands. Flamingos exemplify this difficulty because their subtle sexual dimorphism makes sex identification complex. Recent advances in technology offer non-invasive methods for collecting demographic data from a distance, providing new opportunities for wildlife research. This study tested photogrammetric techniques, methods that obtain quantitative measurements from photographs, to assess sex in Chilean Flamingos (Phoenicopterus chilensis) by collecting key morphological data from standardized images. Captive flamingos, sexed by molecular techniques, were photographed to validate the method’s accuracy. Subsequently, the same techniques were applied to wild, free-ranging flamingos to evaluate the influence of distance, image quality, and measurement choice on identification success. Results showed that photogrammetric methods could reliably identify the sex of both wild and captive flamingos. However, accuracy depended on selecting appropriate measurements, careful application of the method, and maintaining optimal distances between the photographer and the subject. These findings highlight the potential of photogrammetry as a practical, non-invasive tool for gathering reliable demographic data. By integrating advanced technology into conservation strategies, this approach can enhance ecological studies and improve management practices for flamingos worldwide.