You’re out birding at the local marsh, facing a sea of cattails and reeds. Somewhere in that vast expanse is a Black Rail. How in the world are you going to find it? What are the odds of it sauntering out of the dense growth right in front of you? If left to their own devices, very few Black Rails—and other very secretive birds—would show up on any birders’ life lists.
Birders do check off rails—and Swainson’s Warblers, nocturnal owls, and other hard-to-find species. Frequently these birds are prodded into announcing their presence by the use of recordings.