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: