The bobolink migrates from North America to South America and is the only North American songbird known to molt during its southbound journey.
Bobolinks breed in open grasslands and hayfields across much of Canada and the northern United States. After breeding, they travel south through the Americas to winter mainly in the grasslands of Argentina, Bolivia, Paraguay, and Brazil.
Their migration is especially demanding because adults undergo a complete molt while moving south. This unusual strategy is called a prebasic molt on the wintering grounds or along the route, and it replaces worn feathers before the bird settles into the nonbreeding season.
Bobolinks were once commonly called rice birds because large flocks fed in rice fields during migration. Habitat loss in both breeding and wintering areas has contributed to long-term population decline.