Warblers are small, often colorful woodland songbirds that pass through Illinois during spring and fall migration. Most nest in the northern United States and Canada, and migrate to the southern United States, the Carribbean, Central and South America.
Due to this long, grueling migration, stopovers to rest and refuel are very important. In central Illinois, migrating songbirds can be found where large, unbroken tracts of forest remain. They are also seen in large city parks. Few warblers nest in Illinois, so the best time to see them is in the spring and fall.
Because of their small size, and the fact that many warblers spend their time in the forest canopy, they may pass unnoticed by many people.
Identifying warblers in the fall is more difficult. By this time, many have lost their distinct breeding plumage and are a drab olive green. The addition of the nesting season's immature birds makes things confusing, even for the experienced naturalist.
Warblers have generally declined in numbers over the years due to loss of habitat and the fragmentation of large forested areas. Breaking forests apart with roads and development invites those predators that live near the forest's edge into the interior where songbirds live. Raccoons, blue jays, cowbirds and others can make life precarious for nesting songbirds.
Developing awareness of these colorful and interesting birds is the first step in their conservation. Take a walk this spring and fall. Scan the tops of the trees for warblers. You may discover a world others have been missing.