Corn crakes was first described by Linnaeus in his Systema Naturae in 1758 as Rallus crex , but was subsequently moved to the genus Crex , created by German naturalist and ornithologist Johann Matthäus Bechstein in 1803 , and named Crex pratensis . The earlier use of crex give it priority over Bechstein 's specific name pratensis , and lead to the current name of Crex crex . The binomial name , Crex crex , from the Ancient Greek " κρεξ " , is onomatopoeic , referring to the crake 's repetitive grating call . The common name was formerly spelt as a single word , " corncrake " , but the official version is now " corn crake " . The English names refer to the species habit of nesting in dry hay or cereal fields , rather than marshes used by most members of this family .