On our latest show: Do birds sing in their sleep? — a Science Corner report. Plus, listener audio postcards from the Great Dismal Swamp, and the Pocosin National Wildlife Refuge; and backyard birding observations from Al Batt in Minnesota and Mike O’Connor on Cape Cod.

On our latest show: The warblers that use nest boxes; the Biggest Week in American Birding; highlighting Earth Day; and a groovy member of the cuckoo family.