Researchers from the Museum of Southwestern Biology (MSB) at the University of New Mexico (UNM) have revealed the long-distance migration patterns of the giant hummingbird, a discovery that has also led to the identification of a new species. The study, "Extreme elevational migration spurred cryptic speciation in giant hummingbirds," published in Proceedings of the National Academy of Sciences, is the result of an eight-year investigation.
The research team, led by Jessie Williamson, UNM Ph.D., 2022, comprised members from various institutions including UNM's MSB, Pontificia Universidad Católica de Chile in Chile, and Centro de Ornitología y Biodiversidad in Peru. The researchers initially aimed to determine where these migratory giant hummingbirds spent their winters. The birds, approximately eight times larger than a Black-chinned hummingbird, breed along central Chile's Pacific Coasts but disappear after breeding.
By attaching miniature backpack tracking devices to these birds, Williamson and her international team discovered that migratory giant hummingbirds ascend over 13,000 feet to reach the high Andes and fly as far north as Peru. This roundtrip journey spans more than 5,200 miles - roughly equivalent to the distance between New York City and Buenos Aires.
Williamson devised a method for affixing miniature 'backpack' tracking devices that were lightweight enough for hummingbirds and did not hinder their unique style of flight. This technique was detailed in a paper she published in the Journal of Avian Biology in 2021.
The research team also found that migratory giant hummingbirds do not simply ascend to high altitudes; they pause their upward climb for several days to allow their blood and lungs to acclimate. This strategy mirrors that used by human mountaineers.
Genome sequencing on museum specimens enabled the team to differentiate between two forms of giant hummingbirds for the first time. Historic specimens led the team to the significant finding that migratory and high-elevation resident giant hummingbirds had been evolving separately for about three million years, making them distinct species.
The resident giant hummingbird population in the high Andes is larger and has notably different blood and lungs than the migratory form. As a previously unrecognized species (Patagona sp. nov.), it required a name. After consulting with scholars, the team proposed the name Patagona chaski, recognizing shared characteristics between giant hummingbirds and the high-altitude adapted, fleet-footed chaski messengers of the Inka empire.
This research was made possible through international collaborations among institutions in the United States, Chile, and Peru, as well as support from generous landowners in Chile and rural communities in Peru. The research team comprised authors, students, and field assistants who conducted dedicated fieldwork from sea level to high Andean peaks.
