This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: In 1899, scientists began tracking avian migration by placing a small ring with an identifier around birds' ankles. Researchers then had to recapture the birds elsewhere, leaving the journey between those points a mystery.
Today, GPS tags allow researchers to see every stage of bird migration. The tags are small, have long-lasting batteries and solar panels, and track dozens of metrics. Migration is no longer described as just a theoretical range but rather as an exact map.
Despite this technological advancement, the routes of many species in their respective flyways remain undescribed. Now, a new satellite tracking study led by a University of Utah undergraduate describes the journey of migratory raptors along the understudied East Asia–East Africa Flyway. The steppe eagle, Aquila nipalensis, a highly endangered raptor species, has been tracked before.
However, Nathan Murthy's was the first satellite-tracking study of the booted eagle, Hieraaetus pennatus, in this flyway. The East Asia–East Africa Flyway crosses more than 60 countries and stretches from northern breeding grounds in Siberia and eastern Russia to wintering sites in eastern and southern Africa. Many of the more than 330 bird species along the corridor have to navigate major bottlenecks in the Middle East, including large bodies of water and growing anthropogenic stressors such as persecution, falconry, habitat loss, increased pesticide use and collisions with power lines.
Wildfires, advancing spring arrival times and extreme El Niño events also pose challenges. "These journeys are spectacular and difficult—spanning thousands of kilometers," said Murthy, whose study began in the lab run by Çağan Şekercioğlu, a Utah biology professor and renowned birder. "But we just catch glimpses.
A bird perched here, a bird soaring there—we get to join them for a brief second, but that's it." He wanted to know more: what those glimpses actually mean. Ultralightweight GPS-GSM transmitters were placed on the steppe and booted eagles at the Aras River Ornithological Station in northeastern Turkey in September 2022 and 2021, respectively. When released, the eagles began their fall migrations right away.
Extract — continue reading at the source.
