They are still here, but whip-poor-will populations are on the decline in Illinois and the Midwest. Whip-poor-wills are migrants and summer residents in Illinois. They inhabit deciduous or mixed deciduous-coniferous forests with little underbrush. Habitat loss and degradation is the main cause in their decline. They prefer dense forest with an open understory. They typically will not use disturbed wooded areas or grazed woodlands. They best thing that you can do for them, and for other bird species that are on the decline, is to protect habitat that remains and try to restore habitat where possible.