Cerulean Warbler: Dendroica cerulea
Cerulean warblers are strikingly beautiful. Adult males are a vibrant blue color on their backs and heads, and white below, with a dark breast band and dark streaks. Adult females are blue-green above, pale yellowish below.
As they fly between their wintering areas in South America and nesting sites in the United States and Canada, they alight only briefly in Florida, part of the migratory songbird contingent that sweeps in waves over our state every spring and fall. And like many of the songbirds they migrate with, their numbers are declining.
The decline of cerulean warblers and other migratory songbirds is due primarily to the destruction of natural habitat on breeding and wintering areas and along migration routes. Not only have virgin forests been cleared for human development, but also remaining undeveloped land has been broken into small parcels (forest fragmentation). More than 200 species of birds migrate between their breeding grounds in the United States and Canada and their wintering areas in Mexico, Central and South America or the Caribbean.
Cerulean warblers winter on the east slope of the Andes from Colombia to Peru, and in the forested mountains of Venezeula. In North America, their breeding habitat is usually mature deciduous forests with an open understory. They eat insects gleaned from the forest canopy.
In North America, the biggest threats to cerulean warblers include the loss and fragmentation of mature deciduous forests, especially along stream valleys; shorter rotation periods and even-aged management on timber harvest lands; and perhaps the loss of key tree species due to introduced pests. On the wintering grounds, the conversion of mountain forests to pasture and coca seems to be the greatest problem. In North America, conservation efforts directed at this species include land acquisition and protection.