Cerulean Warblers share some of the same habitat requirements as Red-shouldered Hawks: tall, large-diameter trees, diciduous riparian forests with small canopy openings, often associated with steep valley slopes. During songbird surveys within our Red-shouldered Hawk territories in the early 2000's we noticed an unusual number of Cerulean Warblers. Since the mid-2000's, funding has allowed ongoing point-count surveys in Effigy Mounds National Monument, Yellow River State Forest, USFWS lands along Pool 10 of the Mississippi, Pike's Peak State Park and three Wildlife Management Units in northeast Iowa. The abundance of Cerulean Warbler records resulted in the designation of the Effigy Mounds/Yellow River State Forest Globally Important Bird Area. Cerulean Warbler survey season begins in mid-May with the birds' return from their forested South American wintering grounds and continues through mid-July after fledging is complete.