Humpback whales ( Megaptera novaeangliae ) attend both Mexico and Hawaii breeding grounds in the same winter: mixing in the northeast Pacific

Definitive evidence shows that humpback whales (Megaptera novaeangliae) can attend both Mexico and Hawaii breeding grounds within the same winter season, challenging the presumed seasonal isolation of these populations. Two whales were photo-identified at both locations: one traveling from Maui, Hawaii to the Revillagigedo Archipelago in 53 days (2006), and another moving from Guerrero, Mexico to Maui in 49 days (2018). These findings, combined with additional data on individual interchange, song similarity, and mid-ocean detections, suggest that these populations may not be as distinct as previously classified. The study relies on long-term photo-identification records and genetic sampling to track whale movements across the northeast Pacific.

Darling, J. D., Audley, K., Cheeseman, T., Goodwin, B., Lyman, E. G., & Urbán, R. J. (2022). Humpback whales ( Megaptera novaeangliae ) attend both Mexico and Hawaii breeding grounds in the same winter: mixing in the northeast Pacific. Biology Letters, 18(2). https://doi.org/10.1098/rsbl.2021.0547