Vocalizations distinguish the cryptic giant hummingbird species and clarify range limits

Robinson B.W.; Zucker R.J.; Witt C.C.; Valqui T.; Williamson J.L. · Journal of Field Ornithology (2026) · DOI: 10.5751/jfo-00750-970110

Resumen

Vocal traits are often essential for distinguishing phenotypically cryptic taxa. The hummingbird genus Patagona comprises two species that differ in important aspects of their ecology and physiology but that are near identical in plumage and morphology: The Northern Giant Hummingbird (Patagona peruviana) and Southern Giant Hummingbird (Patagona gigas). Here, we characterized vocalizations of both giant hummingbird species and assessed whether vocalizations can be used to distinguish the two. We recorded Patagona vocalizations in Peru, Bolivia, and Chile in 2023 and 2025 and used public data to analyze vocal trait variation of 217 individuals recorded from across the range of the genus. Sampling spanned 49 years, >36 degrees of latitude, and >4300 meters in elevation. We first quantified species-level vocal differences of individuals across allopatric breeding ranges and trained a linear discriminant model to identify individuals to species. The trained model had 100% classification accuracy. We then used our trained model to identify individuals recorded during co-occurring, non-breeding periods of overlap, and subsequently analyzed range-wide vocal variation; this model had 97.3% classification accuracy (2.7% error rate; two individuals misidentified). We found striking vocal divergence between the two species, uncovering that Northern and Southern Giant Hummingbirds can be reliably and easily identified by vocalizations across their ranges and during any month of the year. We provide new data on the range limits of both species in west-central Bolivia, highlighting a previously unknown zone of overlap around Lake Titicaca. Unlike other phenotypic traits, vocalization provide a robust method for identifying the giant hummingbird species, opening doors to future research on ecology, trait evolution, hybridization dynamics, and conservation of the world’s largest hummingbirds.

Instituciones: Universidad Nacional Agraria La Molina