The conservation implications of site fidelity: a case study involving nearcticneotropical migrant songbirds wintering in a Costa Rican mangrove

The ecological and conservation implications of site fidelity among nearctic-neotropical migrant songbirds wintering in a Costa Rican mangrove forest were exam-ined. During two boreal winters, 168 (24%) of 700 indi-viduals were captured more than once within winter seasons. Among these, birds from six of 15 migratory species were re-trapped. The vast majority of recaptures were either prothonotary warblers Protonotaria citrea or northern waterthrush Seiurus noveboracensis. Between winters, only prothonotary warblers, northern waterthrush and yellow warblers Dendroica petechia were recap-tured, with 55 (16%) of 336 individuals originally caught in winter 1990-91 being re-trapped in winter 1991-92. Examination of body condition indices revealed n