Traditional Bird Base

The traditional crane (orizuru) is the most famous model folded from the bird base, along with the flapping bird, various songbird designs, and other bird figures. The bird base provides four elongated triangular flaps that naturally correspond to a bird's head, tail, and two wings.

The bird base is folded from a preliminary base (also called the square base) by performing petal folds on two adjacent sides. This creates a compact form with four long, narrow flaps radiating from a central point, ready to be shaped into the head, tail, and wings of the finished model.

The bird base produces four long, narrow flaps ideal for slender forms like crane necks and wings, while the frog base produces shorter, wider flaps commonly used for the traditional jumping frog model. Both are derived from the preliminary base but use different petal-folding sequences to achieve their distinct flap configurations.

The bird base has been used in Japanese origami for centuries and is one of the foundational bases in the classical tradition. The traditional crane, which begins from a bird base, is one of the oldest known origami designs in Japan, with historical roots going back several hundred years.