Use of "definitive" and other terms in molt nomenclature: A response to Wolfe et al. (2014)

Abstract

Ornithologists have largely embraced the molt terminology of Humphrey and Parkes (1959) as modified by Howell et al. (2003; the H-P-H system). In a recent commentary, Wolfe et al. (2014) summarized the derivation and benefits of HP-H terminology, suggested slight modifications, and promoted analyses on the evolution of molts using H-P-H nomenclature. We appreciate the timeliness of Wolfe et al.'s review and agree with most of their conclusions and modifications. We disagree, however, with Wolfe et al.'s proposal for introducing a new and restricted use of the term "definitive" in H-P-H nomenclature. To avoid confusion, we recommend that definitive plumage and definitive molt cycle continue to be used as defined by Humphrey and Parkes (1959) and Howell et al. (2003), respectively, as terms indicating that plumage appearance and molt cycle have achieved stasis. We also recommend that the term "plumage" can be used more widely than the definition proposed by Humphrey and Parkes (1959), and that the term "juvenal" can henceforth be replaced by "juvenile" in molt and plumage literature.