FIGURE S1. Relationship between quality of original descriptions of species (1935–1999) and subsequent revision in five periods of 13 years. Significance levels (*P < 0.05, **P < 0.01) are based on Mann-Whitney U test (A, pages, specimens, characters, taxa compared) and Fisher’s Exact Test (B, illustrations, maps, sonagrams). N.s., not significant.

New species of birds described in 1935-2009, including details on authorship, number of pages, specimens, characters, and taxa, and presence/absence of illustrations of the new species, maps and sonagrams.