Integrating season-specific needs of migratory and resident birds in conservation planning

Efforts to conserve migratory species have been challenged by a poor understanding of their temporally-dynamic distributions over large geographies. Consequently, most conservation plans have focused on the stationary periods despite the importance of migratory periods for overall population dynamics and fitness. Strategies that identify stopover sites for migratory species during migration and examine the potential for those sites to protect resident species may offer an efficient approach to enhance the conservation of both groups. Using crowd sourced data (i.e., eBird), we identified priority stopover sites (PSSs) that target protection of 30% of the seasonal average abundance of over 400 Nearctic-Neotropical migratory bird species in the Americas during spring and fall migratory periods. We then calculated the proportion of global abundance of 158 resident bird species including 27 imperiled species, that were captured on those sites, analysed the extent to which sites were protected, and forecast changes in land use. Around half or less of PSSs were shared between spring (52-54%) and fall (23-32%), indicating that planning efforts should be season-specific. Less than 10% of PSSs were protected, while 30-46% were in human modified landscapes. Even though our spatial algorithms targeted 30% of the abundance of migratory birds, comparable proportions of resident bird populations were also captured (36% of resident and 42% of imperiled bird populations in fall, 22% and 31% respectively in spring). Our findings demonstrate that protecting stopover sites for migrating species can provide co-benefits for resident and imperiled species.