The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with naked as a jaybird
Bare, unclothed, as in I came straight out of the shower, naked as a jaybird. This simile replaced the 19th-century naked as a robin and is equally unclear, since neither bird is normally stripped of its feathers. Further, the bird it refers to is more often called simply “jay” rather than “jaybird,” yet the latter is always part of the simile.
[ c. 1940