The contribution of citizen science to research on migratory and urban birds in Brazil

For ages, the wide variety of colors, shapes, and behaviors of birds have attracted the attention of nature observers and professional ornithologists. Birdwatching represents an important source of data on many aspects of bird biology worldwide, particularly in Brazil, a highly biodiverse country. We reviewed the current state of citizen science with regard to Brazilian birdwatching by evaluating (a) where, (b) how much, and (c) what kind of data are collected by birdwatchers. To highlight the potential contribution of such data, we used citizen science data to evaluate the migration timing and habitat occupancy of four migratory bird species whose movements are still understudied. In addition, based on our assessment, we suggest new avenues for citizen science-based research on migratory bird ecology in Brazil. Finally, given that the urban ecology of numerous Brazilian birds is still poorly understood, we highlight how this can be remediated through the efforts of birdwatchers, given that 73% of the data is concentrated within or nearby large urban centers in southern and southeastern Brazil. We show that data generated by citizen scientists can be useful for a suite of studies, such as on habitat use and migration patterns of Brazilian birds. Therefore, citizen science is an important way to improve our knowledge about Brazilian birds and promote their conservation in an era of rapid change. Nevertheless, its impact in the long term will depend on improving the quality of the data and involvement of more birdwatchers.