Non-Modular Birds: 14

The boxes shown at left are based on a design by Simon Andersen. His model was intended to be a flat hanging ornament, but I accidentally discovered how to make it a three-dimensional box by flattening out a sink fold hidden inside the bird's body.
 
The swan boxes shown at right were designed by Laura Kruskal, the robin boxes shown below were designed by Leyla Torres, and the boxes featuring four birds were designed by David Lister.
 
Each model on this page requires only one sheet of square paper, so why not fold a whole flock of birds? Filled with small treats, they will make any occasion more joyful.