Theme 1-16 (AKA Wooden Crate) is the 16th level of Poached Eggs. This level marks the first appearance of Yellow Bird.
Shoot the first bird at the first small pig, which would cause the large pig above it to crash down and die as well. Do the same for the second set of pigs. The player should receive 30,000 extra points for the unused birds.
In the Chrome version, there is a CS at the top of the screen on a platform. To get to it, fire a Yellow Bird into the air, and click as soon is it leaves the slingshot.