A Few Bird Pics From The Trip That Went Wrong

 Where Do I Land ?

 Pelican

 Pied Butcher Bird

 Peaceful Dove

 Red Browed Finch

 Kookaburra

Cormorant Drying In The Sun

Blend If (Photoshop CS)

You can use the Blend If feature of photoshop to replace an area of uniform color.

Here are a couple of tutorials on it:

Replace Sky (layer masks)
SOLD REAL ESTATE SKY REPLACEMENT TUTORIAL Just Became Easier