To Confirm:
Ancestry's database is called New England, The Great Migration and The Great Migration Begins, 1620-1635 . It's data and images are Anderson's
Ancestry.com. New England, The Great Migration and The Great Migration Begins, 1620-1635 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2013.
Original data: Anderson, Robert Charles. The Great Migration Begins: Immigrants to New England, 1620-1633, Volumes 1-3; The Great Migration: Immigrants to New England, 1634-1635, Volumes 1-6. Boston: New England Historical and Genealogical Society, 1996-2011.