I was intrigued with this pattern, having never seen it before. I went looking & I found a number of patterns very similiar but this one is a match, I believe.
Here is what I found:
(Moderators, if I am violating copyrite, please remove as that it NOT my intent!)
Information & px is copied from : ( I have re-colored the original to somewhat match yours.)
Quoting from: Barbara Brackman's Block Base
"This pattern was published in the 1920 & 1930's by Ruby McKim &
Kansas City Star. This pattern was known by several names, depending on when it was published.
Four Birds
Four Swallows
Blue Birds
Dove in the Window
Dove at the Window
Dove in the Window
[ATTACH=CONFIG]17052[/ATTACH]