Extreme Elevational Migration Unveiled: A New Species of Giant Hummingbird

Tuesday - May 14 2024, 22:26 UTC - 6 months ago

A team of researchers discovered the migratory patterns of the giant hummingbird, leading to the discovery of a new species and uncovering their extreme long-distance migration. They found that the giant hummingbird travels over 13,000 feet in elevation, flies more than 5,200 miles roundtrip, and uses the same acclimatization strategy as human mountaineers. The new species, Patagona gigas, is found only in South America and has relatively dull coloring and unique vocalizations. The team plans to continue their research to learn more about these remarkable birds and their resilience to climate change.

Researchers from the University of New Mexico’s Museum of Southwestern Biology (MSB) have uncovered the giant hummingbird’s extreme long-distance migration for the first time. Their eight-year study, “Extreme elevational migration spurred cryptic speciation in giant hummingbirds,” published this week in Proceedings of the National Academy of Sciences, led them to another important discovery: The world’s largest hummingbird is a new species.

The team, led by Jessie Williamson, UNM Ph.D., 2022, included the Museum of Southwestern Biology at UNM, Pontificia Universidad Católica de Chile in Chile, and Centro de Ornitología y Biodiversidad in Peru. Initially the researchers wanted to figure out where these migratory giant hummingbirds spend the winter. The birds, which are about eight times the size of a Black-chinned hummingbird, breed along the Pacific Coasts of central Chile but ‘vanish’ after breeding. This mystery had remained unsolved since the 19th century when Charles Darwin observed the migratory giant hummingbirds during his voyage on The Beagle. At that time, Darwin speculated that the hummingbirds migrated to the Atacama Desert region of northern Chile.

By affixing miniature backpack tracking devices to hummingbirds, Williamson and her UNM-led team of international collaborators discovered that migratory giant hummingbirds ascend over 13,000 feet in elevation to the high Andes, flying as far north as the mountains of Peru. This roundtrip migratory journey covers more than 5,200 miles – about the distance between New York City and Buenos Aires.

To make the discovery, Williamson developed a method for attaching miniature ‘backpack’ tracking devices that were small and light enough for hummingbirds and did not interfere with their hovering style of flight. She published a paper describing this method in the Journal of Avian Biology in 2021.

“It took a lot of trial and error to come up with a suitable harness design,” said Williamson. “Hummingbirds are challenging to work with because they are lightweight with long wings and short legs. They’re nature’s tiny acrobats.” .

One of the research team’s novel discoveries was that migratory giant hummingbirds don’t just fly straight up to high altitudes–they pause their upward climb for periods of days to allow their blood and lungs to acclimate. In this way, the giant hummingbirds employ the same acclimatization strategy used by human mountaineers.

“Nobody had figured out where migratory giant hummingbirds go because they were hiding among the non-migratory giant hummingbirds,” said Professor and Director of the Museum of Southwestern Biology Christopher Witt, who advised Williamson’s dissertation work. “The two forms of giant hummingbird look almost identical — for centuries, ornithologists and 19th century explorers thought they were the same species. Using molecular methods, our team showed that they are genuinely distinct and the world’s largest hummingbird is in fact a new species.” .

The team traveled to Chile and Peru in multiple field seasons to survey and sample giant hummingbirds from breeding and non-breeding grounds. In addition to the tracking data, the researchers used genetics to support their findings.

Through the genome sequencing of giant hummingbirds from both regions, the researchers found strong evidence that the giant hummingbirds underwent a rare split into two distinct species. This process, known as speciation, occurs when one ancestral population becomes separated and evolves into two genetically distinct populations that can no longer interbreed.

This discovery was bolstered by the fact that the giant hummingbirds in the Atacama neat the Chilean coast showed signs of isolation from other populations. This isolation could have driven the speciation process.

The scientists believe that the giant hummingbird evolved and adapted to the mountainous regions due to the changes in climate over time that may have caused their original breeding grounds to become unsuitable.

The newly discovered species has been named Patagona gigas, the giant hummingbird. This species is the largest member of the bearded hummingbird genus, Patagona, found only in South America. Compared to other species of hummingbirds, the giant hummingbird has relatively dull coloring and does not produce the characteristic humming sound. Instead, its vocalizations sound more like the squeaks of a rubber balloon.

The giant hummingbird’s long-distance migration made the discovery even more astounding to the research team. The physical ability of the species to undertake such an extreme migration is a testament to the incredible resilience and adaptability of these birds.

The team plans to continue their research on the giant hummingbird species and to expand their studies to other species of hummingbirds in South America. They hope to uncover more about their migration patterns, genetic diversity, and the impact of climate change on these remarkable birds.