“…Fork‐tailed Flycatchers are known to track rainfall during winter (MacPherson et al, ), arriving at the wintering grounds in northern South America at the beginning of the wet season, which peaks in July and August (Poveda, Waylen, & Pulwarty, ) and where Fork‐tailed Flycatchers undergo an annual flight feather molt (Jahn, Giraldo, et al, ; Jahn, Seavy, et al, ). Winter represents a critical period during which they must properly time flight feather molt prior to spring migration, since Fork‐tailed Flycatchers generally avoid molting and migrating simultaneously (Jahn et al, ). Given that northern South America is susceptible to notably lower rainfall levels in some years (i.e., during the “El Niño” phase of the El Niño/La Niña climatic cycle, Poveda et al, ), understanding the relationship between interannual variation in food resource availability, which is key to completing feather molt (Jahn, Giraldo, et al, ; Jahn, Seavy, et al, ), and the timing of events in the flycatcher's annual cycle, will provide novel insights into the constraints molding the annual cycle and population dynamics of this and other species migrating within South America.…”