Edit: even if you've missed several days (or all of them), you can go through this list after-the-fact (but while promo is ongoing) and catch a bird at each of the sites.
List of clue answers
Match.com
1800Flowers
Godiva
Restaurant.com
Blue Nile
GiftBaskets.com
CheapoAir.com
Zales
Paper Mart
skinstore.com
Groupon
Sugarfina
Things Remembered
Spafinder
The paper store
FTD
Priceline
Russel Stover
Jared The Galleria of Jewelry
eHarmony
Kay Jewelers
TopCashback Valentine's Treat, hunt for hummingbirds