Little Bronze-cuckoo (Chrysococcyx minutillus) - HBW 4, p. 563

Taxonomy: Chrysococcyx minutillus Gould, 1859, Port Essington, Northern Territory.
Asian and Australasian forms of Chrysococcyx sometimes placed in genus Chalcites. Species formerly known as C. malayanus, but type of that name was a female of C. xanthorhynchus. Present species might be better considered to constitute more than one species, but the songs of all forms, where known, are apparently identical. While the forms listed are generally allopatric, and all use the same type of host species, the occurrence of two forms (cleis, aheneus) in Borneo suggests possible separate species status: russatus group (aheneus, jungei, misoriensis, poecilurus, russatus and undescribed race from Timor) sometimes treated as a distinct species from minutillus group (peninsularis, albifrons, cleis, minutillus and barnardi) due to apparent sympatry without interbreeding in Borneo, but this may involve migrant birds, and both forms interbreed extensively in N Australia (russatus with barnardi). Races rufomerus and crassirostris are also often treated as two separate full species, or as races of one distinct species, on grounds of claimed morphological and ecological differences; race salvadorii (known only from type specimen) sometimes considered intermediate between these two, and sometimes included within latter race. Thirteen subspecies currently recognized.