Solution to Challenge 3

Folding the bird
1. Fold the preliminary base, then the bird base (a petal fold front and back).
2. Narrow the two long points if your diagram asks you to, then make an inside reverse fold on one for the neck and on the other for the tail.
3. Make a small inside reverse fold at the tip of the neck for the head.
4. Fold the wings down on each side, then bring them back up slightly so they stand open.
5. Hold the bird at the join of neck and body, pull the tail straight down gently, and the wings flap.

If it does not flap smoothly
The most common causes are neck or tail folds that are too tight (so the body cannot bend at the join), wings creased too sharply near the body, or a tail pulled sideways rather than straight down. Soften the wing creases, loosen the reverse folds a little, and pull straight.

Comparing the two sizes
Most people find the 15 cm square easier to fold accurately, because a 0.5 mm slip is a smaller fraction of the work, and the layers are easier to separate when you make the reverse folds. The 10 cm bird is neater and lighter but fussier. A smaller bird often flaps just as well, sometimes better, because it is lighter; your result depends on your paper. The point to take away is that errors scale with the fold, not with the paper, so a smaller model is less forgiving.

Checkpoint: the neck and tail point up at roughly the same angle, the head is small and neat, and the wings move freely when the tail is pulled.