Revealing the secret paths of illusive migrants

Some birds are extremely illusive and difficult to track systematically, making their migratory pathways hard to study and conservation management difficult. Employing stable isotope methods can provide some information, but as large geographic regions share isotope populations, such indications are often very broad. In this study, researchers use GBIF-mediated occurrences relying on citizen science observations to refine hydrogen isotope estimates of migratory origins of the secretive Virginia rail (Rallus limicola). Combining methods, the researchers produced high-resolution estimates of the origins of migrant birds, showing that 45 per cent of individuals from Louisiana had breeding origins outside the Mississippi flyway, and less than 20 per cent of Texas individuals originated in the Central flyway, both refuting previous assumptions. The results highlight the need for species-specific migratory studies, as management strategies based on surrogate species may be inaccurate, as indicated by the study.