Throughout this website, distributions are indicated by a code that is based on the following world-map scheme:
The distribution of a given bird taxon is indicated by a block of nine
boxes, with each box representing a defined region of the word. If a bird taxon does occur in a given region, the box representing that region is filled with the corresponding colour.
White boxes indicate that a given bird taxon is not naturally occurring in that part of the world.
The distribution code is most easily explained by a number of selected examples: