The Cerulean Warbler, like other Neotropical migrants, has suffered extensive loss of breeding habitat during the past century. It differs from many other migrants in its preference for mature floodplain forest with tall trees, a habitat that has become scarce over much of the warbler's original nesting range. Sensitivity to fragmentation within remaining suitable tracts places this warbler at an additional disadvantage. Furthermore, Cerulean Warblers winter strictly in primary, humid evergreen forest along an extremely narrow elevational zone at the base of the Andes. This zone is among the most intensively logged and cultivated regions of the Neotropics. From 1966 to 1987 the Cerulean Warbler showed the most precipitous decline of any North American warbler (3.4% per year). Unless steps are taken to protect large tracts of habitat of this ecologically specialized species, both on the breeding grounds and in the Andean foothills, we believe the future of this warbler is in serious jeopardy.