Cerulean warblers have a light blue (males) or blue-green (females) back. The chest and throat color in males is whilte and in females is white with a light wash of yellow. Cerulean warblers have two broad white wingbars, white tail spots and a dark blue band across their breast. Their wings are long and pointed and they have a short tail.
Cerulean warblers were once among the most abundant of all warblers that bred in the Ohio and Mississippi River Valleys. But since the 1960s the species has declined drastically and is considered to be vulnerable. The species is considered to be among the fastest declining warbler species in the United States. The main threat to cerulean warblers is that brought on by habitat fragmentation and destruction throughout their breeding, migratory and wintering habitats. Additional threats to cerulean warblers are collisions with radio and television towers.
Conservationists have been establishing conservation programs to protect cerulean warblers and other neotropical migrants. Their objective is to preserve vital habitat for the birds and in doing so stabilize and protect the viability of the species. Most recently, The American Bird Conservancy and Fundacion ProAves purchased nine properties in Columbia along the western edge of the Pauxi Pauxi Reserve, a nature reserve established in 2007. This land expands the existing reserve and provides crucial winter habitat for cerulean warblers.
During their fall migration southward, cerulean warblers begin their long journey quite early in the season when compared to other migratory birds following similar routes. Some cerulean warblers arrive their winter grounds as early as August.
The migratory route cerulean warblers follow passes through areas of sthe outheastern United States before crossing over the Gulf of Mexico. Cerulean warblers also occasionally stopover in parts of Central America, before continuing on to their winter range in South America. The winter range of cerulean warblers stretches from Columbia to Peru and Bolivia and lies along the eastern slopes of the Andes mountain range.
Cerulean warblers are members of the New World warblers. Among their closest living relatives are species such as the Cape May warbler, Kirtland's warbler, American redstart, arrow-headed warbler, chestnut-sided warbler and the black-throated blue warbler.