In Angry Birds Rio, I can't seem to find the fifteenth watermelon; where is it hiding?
I'm on my iPhone if that helps. I've found the ones on the following levels:
5-5, 5-11, 5-13, 5-14, 5-15, 6-2, 6-3, 6-4, 6-5, 6-6, 6-7, 6-9, 6-12, 6-14
I found that this one is "invisble" on the iPhone (but it appears to be visible on other platforms from anecdotal evidence)
The remaining one is on 5-2, triggered by hitting the TNT box to the far right of the screen, past the umbrella and water ring. This causes a new box on a chain to fall from the sky.
(self-answer due to this one was tricky for me and I couldn't find it for a long time -- 3 stars on all the levels before I found this one!)