We might assume it's because the grass is greener on the other side. But this month's study suggests that some migrant Sanderlings headed to the tropics are getting less than they bargained for. Tune in to our chat about the costs and benefits of migration, the importance of falsifying hypotheses, the logistics of studying a species over 13,000 kilometers, and how wintering habitat can make or break success on the breeding grounds. Find the article here: "Low fitness at low latitudes: Wintering in the tropics increases migratory delays and mortality rates in an Arctic breeding shorebird" (Reneerkens et al 2019).