Reliability of morphological criteria for sexing birds during ringing, assessed using molecular methods – a study of thirteen species of passerines and near passerines

Understanding the ecology and conservation of bird species often requires accurate sex determination individuals. Species with sexually dimorphic plumage can usually be sexed in hand based on consistent definitive differences between sexes, but there are challenges related to (1) how sexual dimorphism develops age, (2) individuals that show intermediate visible morphological traits, or (3) subtle trait require considerable experience use reliably. monomorphic plumage, which constitute over half all avian globally, pose a greater challenge not hand. The aim this study was molecular methods identify definitively both caught at ringing site south-west Portugal, order evaluate standard sexing techniques for showing biometric measurements. Blood samples were collected from range during ringing, DNA extracted. Molecular successful identifying 202 across 13 birds (eight five plumage). field six eight discrepancies two identified Pied Flycatcher Ficedula hypoleuca Eurasian Hoopoe Upupa epops. Finally, measurements taken used assess whether could have been correctly males females reported literature.