Though this feels like a modern invention, Jay has been in use for centuries. Early Jays often were named in honor of founding father John Jay, whose surname derived from the jaybird. A popular midcentury choice, Jay was in the Top 100 from 1953 to 1970. In the last couple of decades he was replaced by such more elaborate forms as as Jayden, Jalen, and Jayce. But Jay could make a comeback in tandem with cousins May, Kay, Fay, and Ray. Now at Number 391 in the US, Jay is ranked Number 60 in Scotland, 85 in Northern Ireland.
In literature, the most prominent Jay wasn't a Jay at all--Gatsby's birth name was James Gatz. In real life, the honor goes to Jay Leno.