Revealing migration schedule and potential breeding grounds of Lined Seedeaters using citizen science data

The Lined Seedeater (Sporophila lineola) is a small intra-tropical migrant songbird. However, little is known about its breeding and wintering grounds, or migratory habits. To investigate potentially distinct breeding populations and the migratory schedule of Lined Seedeaters we analysed its spatial and temporal distribution using published breeding records, museum vouchers, and data from citizen science projects (eBird and WikiAves). Our findings suggest that there are three main breeding areas: northern Argentina and north-western Paraguay, south-eastern Brazil, and north-eastern Brazil, and that the breeding season seems to be restricted to November through May, with slight differences in timing among these three areas. The species winters in the northern part of South America (mostly in grassland areas) and maybe also in the Amazonia. Moreover, rainfall predicts the latitudinal and longitudinal movements of Lined Seedeaters, with the migratory movements associated with an increase in rainfall. Taken together, these results provide a first comprehensive overview on the migration of Lined Seedeater, calling for further empirical field studies. Understanding intra-tropical migratory patterns is paramount to comprehend the potential impacts of environmental change in tropical ecosystems.