Really love how perfectly your birds turned out! For a second, I thought they were prints like the cornerstone squares. Just lovely!
I think a 1/2" stop border would be nice to so it's the same size as the sashing around your bird blocks.
Unless you have some particular applique design in mind that is 7", I would break the border up into 2-3 sections so it doesn't overtake the beautiful work in the center. 14" will be 1/4 of the finished size of your quilt so I'd continue some applique work out into the border to make it as beautiful as the rest of the quilt.
If you really are pressed for time, I'd go with the narrow black stop border, a 3" border that is similar to the pattern on your rug (leaves, scrolls, whatnot -- but a different hue/tone) with cornerstones (more birds?) followed by either a cheater cloth piano key 4" border or a solid border with thread painting of something coordinating with your theme -- birds, branches, leaves, flowers.
If you have a bit more time to put into it, I'd do the black stop border, a pieced 3" border, then a 4" applique border (or an applique border that is broken up into 3 different designs), followed by a black binding. For the pieced border, I might do a 3/4 piano key border (should need 10 jelly roll strips to complete -- cut down the middle). If you really want to be creative, you could even play with the colors in each quadrant so it reflects the changing seasons.
I googled "applique border" and here are some of the designs I thought might work with your quilt with minimal tweaking:
Black borders instead of red, but:
http://www.karenkaybuckley.com/weblo...74-500x666.jpg
Changing seasons border:
http://www.karenkaybuckley.com/weblo...94-500x471.jpg
Possibly my favorite -- realistic flowers:
https://s-media-cache-ak0.pinimg.com...34f328aafe.jpg
Cherries, needs to be on taupe fabric, though:
http://sentimentalstitches.net/wp-co...rder-marks.jpg
The leaves on this one (so tiny, though - ugh!):
https://www.google.com/imgres?imgurl...act=mrc&uact=8
Black scrolls:
https://images.duckduckgo.com/iu/?u=...4b254a.jpg&f=1
Birds on branches:
http://4.bp.blogspot.com/-i5brvpyrvh...uiltsw+006.JPG
Stylized birds (need to replace with realistic birds):
http://simplebirdapplique.files.wordpress.com/2013/10/dscn4662.jpg?w=640&h=360