NUTSHELL BIRDS IN a BARE TREE
A Bird sitting on a tree is never afraid of the branch breaking, because it's trust is not on the branch but on its wings. I have used pistachios shell to create birds which are sitting on the branch of a tree. Some coloring and drawings on a shell changed it like a stock of birds sitting on a bare tree.
Step 1: Bare Tree With Branches
Draw a tree with lots of branches as per your idea. Thicken its root and watch out for its ends. Leave some gap in between each branches so that you can paste a bird there using nutshell.
Step 2: Nut-Shell Art
Pick out good-shaped shell and color it. Draw the lines, features to that. Draw eyes and body lines. Make it like a bird.
Step 3: Nutshell Bird
Place a bird on a branch. Paste it. Draw its eyes and nose. That's all the procedures to make a Nut shell bird.