Taxonomy, nomenclature, and identification of the giant hummingbirds (Patagona spp.) (Aves: Trochilidae)

Giant hummingbirds (Patagona spp.) are extraordinarily large hummingbirds
whose taxonomy has been muddled for two centuries. Patagona systematics
were recently redefined in a study of migration, physiology, and genomics,
revealing two species: the Northern Giant Hummingbird and Southern Giant
Hummingbird. Here, we re-evaluate taxonomy and nomenclature of the genus
in light of its newly clarified biology and species limits,
analyzing data from 608 specimens and wild-caught individuals spanning
1864–2023. The forms gigas and peruviana were both described based on
multiple syntypes. The possible syntypes for Patagona gigas are dubious,
so we designate a neotype for this taxon. The genetic identity of the
peruviana lectotype remains untested, but its plumage appears to match the
northern species. We critically considered the identity and usage
of gigas and peruviana, respectively, and examined identification
challenges that fostered taxonomic uncertainty. We endorse the name
Patagona gigas for the Southern Giant Hummingbird and Patagona peruviana
for the Northern Giant Hummingbird. We found that ~33% of specimens (74 of
226) in major museum collections that are labeled peruviana are actually
misidentified gigas and we include this full list to correct the
historical record. Finally, to facilitate identification and future study
of these two cryptic species, we provide comprehensive information on
plumage, measurements, and seasonal ranges.