Researchers at the National Autonomous University of Mexico have discovered a new species of giant hummingbird that migrates between Chile and Peru, revealing its migration routes and genetic characteristics through innovative tracking and genome sequencing. Researchers at the University of New Mexico's Southwestern Museum of Biology (MSB) have discovered for the first time the extreme long-distance migration of giant hummingbirds. The study, "Extreme High-Altitude Migration Spurs Recessive Species Differentiation in Giant Hummingbirds," published this week in the Proceedings of the National Academy of Sciences, is another important finding from eight years of research: the world's largest hummingbird is a new species.
Researchers at the University of New Mexico have discovered a new species of giant bird, a hummingbird that migrates more than 5,200 miles from Chile to Peru at an altitude of more than 13,000 feet. The eight-year study, which used a miniature tracking device and genome sequencing of museum specimens, made the discovery, showing the significant differences between the migratory giant hummingbird and the resident bird (pictured), which led to the naming of a new species, Patagona chaski.
The research team was led by Dr. Jessie Williamson of the United Nations University and included the UNU Museum of Biology Southwest, the Catholic Bishops' University of Chile and the Peruvian Center for Birds and Biodiversity. Researchers initially wanted to figure out where these migrating giant hummingbirds spend the winter. The bird, which is about eight times the size of the black-bellied hummingbird, breeds on the Pacific coast of central Chile, but "disappears" after breeding. The mystery has remained unsolved since Charles Darwin observed this migratory giant hummingbird on the voyage of the Beagle in the 19th century. At the time, Darwin speculated that hummingbirds had migrated to the Atacama Desert region in northern Chile.
Southern giant hummingbird preparing for takeoff. Image courtesy of Chris Witt
By attaching a miniature backpack tracking device to the hummingbird's body, Williamson and her international team, led by the United Nations University, discovered that migrating giant hummingbirds ascend the Andean mountains at an altitude of more than 13,000 feet and fly north to the mountains of Peru. This round-trip migration is more than 5,200 miles, roughly equivalent to the distance between New York City and Buenos Aires.
To achieve this discovery, Williamson developed a method for installing miniature "backpack" tracking devices that are small and lightweight enough for hummingbirds to not interfere with the way hummingbirds hover. She published a paper in the Journal of Avian Biology in 2021 describing this approach.
"We did a lot of experimentation to design the right harness. Hummingbirds are light in weight, with long wings and short legs, making them challenging to work with. They are little acrobats in nature. "
Southern giant hummingbird carrying a geolocation backpack in Valparaiso, Chile. Image courtesy of Chris Witt
One of the team's new findings is that migrating giant hummingbirds do not fly directly to high altitudes, but instead pause for days to allow their blood and lungs to acclimatize to the climate at high altitudes. This shows that the giant hummingbird uses the same adaptation strategies as human climbers.
Professor Christopher Witt, director of the Southwestern Museum of Biology, advised Williamson on his dissertation work, saying: "No one knows where migratory giant hummingbirds go because they hide among non-migratory giant hummingbirds. The two giant hummingbirds look almost identical – ornithologists and bird lovers have never noticed the difference for centuries. We wouldn't have been able to find this without the miniature tracker."
By sequencing the genome of museum specimens, the team distinguished for the first time two morphologies of the giant hummingbird.
"Natural history collections are absolutely critical to this work," said co-author Ethan Gyllenhaal, current UNM PhD candidate. "Including DNA from 154-year-old model specimens is the key to unraveling this evolutionary mystery."
In fact, these precious historical specimens led the team to the groundbreaking discovery that the migratory giant hummingbird and the high-altitude resident bird have each evolved for about 3 million years, which is enough time for them to become different species.
Dr. Jessie Williamson surveys a giant southern hummingbird in Chile. Image credit: Chris Witt
The giant hummingbird species, which live in the highlands of the Andes all year round, are larger in group size, with distinctly different blood and lungs than migratory hummingbirds. As a previously unrecognized species (Patagona sp. nov.), it needs a name. After consulting with scholars, the team proposed naming it Patagona chaski, in recognition of the common traits between the giant hummingbird and the high-altitude, athletic chaski messenger of the Inka Empire.
This was made possible through international cooperation between U.S., Chilean, and Peruvian institutions, and with the support of generous landowners in Chile and rural communities in Peru. Teams of authors, students, and field assistants carried out specialized field work from sea level to the Andean mountains. In Chile, teams only catch a giant hummingbird every 146 hours. Field crews camped and worked on steep, cacti-covered slopes of the Andes without electricity or running water for weeks.
"This work is just the beginning, and combining migration tracing with genomics gives us research opportunities that can be done in a lifetime," Williamson said.
编译来源：ScitechDaily