Plumage Sequence and Taxonomy of Laysan and Nihoa Finches

Prodromus of the fossil avifauna of the Hawaiian Islands

“…This treatment is supported by Raikow's (1978) myological studies, although Raikow adopted a more conservative nomenclature. It has proven convenient to refer as "subgenera" to the various generic names that were once applied to different sections of the genus Psittirostra (see also Banks and Laybourne, 1977). We recognize the genus Heterorhynchus for the species lucidus and wilsoni, now usually included in Hemignathus.…”

Fifty-sixth Supplement to the American Ornithologists' Union:Check-list of North American Birds

“…In fact, his "Creeper", which is now accepted as five species placed in three genera, may be the most egregious example ever of abuse of the polytypic species concept. Restoration to species rank of many taxa treated as subspecies by Amadon (1950) has now been widely accepted (AOU 1998, Pyle and Pyle 2009, Pratt 2010b, Gill and Donsker 2014 including the Laysan and Nihoa finches (Banks and Laybourne 1977, Fleischer et al 1998; Kauai Amakihi (Pratt 1979(Pratt , 1989aPratt et al 1987;Johnson et al 1989;Olson and James 1991;Conant et al 1998;Fleischer 1994, AOU 1995); Oahu Amakihi Fleischer 1994, AOU 1995); Akekee (Pratt 1989b, AOU 1991, Lepson and Pratt 1997; alauahios and Kakawahie (Pratt 1979(Pratt , 1992bJames and Olson 1991); Akikiki (Pratt 1992b, Foster et al 2000, and the Hawaii Creeper (Pratt 1992b, Lepson andWoodworth 2002). All of these splits comply with Pratt's (2010a) criteria for biological species limits among allopatric island birds.…”

Chapter 7: Revisiting Species and Subspecies of Island Birds for a Better Assessment of Biodiversity

“…So far, genetic studies have shown that remote island birds that look different to humans in the field usually are different species. Appearance also includes the presence or degree of sexual dimorphism (Pratt 1989(Pratt , 1992, variation in maturational stages (i.e., distinctive juvenal or immature plumages), or variation in molt timing or sequence (Banks and Laybourne 1977), all of which can indicate species boundaries.…”