Golden eagles improve their flight skills with age
Researchers at the Max Planck Institute of Animal Behavior in Germany, in collaboration with the Swiss Ornithological Institute in Switzerland and the University of Vienna in Austria, investigated how young golden eagles improve their flight skills as they age. Their results, published in eLife, show that as golden eagles improve their flying skills, they become able to explore a broader area within their range in the central European Alps. Apparently, even seemingly instinctive behaviors require at least some learning in young animals
A juvenile golden eagle carrying a tracking device on its lower back. The data collected by the tracking device allows scientists to understand the development of flight behavior as the birds grow older.
© D. Folkesson
Golden eagles are soaring birds. They ride on upward-moving air currents with open wings, which helps them conserve energy while covering large distances. "However, locating these invisible uplifts and positioning their bodies within the uplifts to gain height is not a simple task. The eagles literally need to learn to fly, at least when it comes to using uplifts." explains Elham Nourani, the lead author of the study.
The team used GPS tracking technology to monitor 55 juvenile golden eagles from nests in Switzerland, Italy, Germany, Slovenia, and Austria. The eagles were tracked for up to three years after leaving their parents' territories, as they flew freely across the central European Alps.
Increased habitat
The team found evidence of this learning process by observing a shift in the eagles' flight patterns. Initially, the young birds flew close to mountain ridges, where winds deflect and move upwards, creating reliably predictable soaring conditions. Over time, they increasingly dared to fly in more open areas where uplifts are less predictable. This transition suggests that as the eagles aged, their ability to find and utilize uplifts improved, making them less dependent on mountain ridges for flight.
The researchers estimated that the flyable areas for the eagles expanded more than 2,000-fold over three years as the birds' honed their flight skills. "Flying is an eagle's defining behavioral trait and you would think that when they fledged they should take to it like fish to water. But apparently they need experience and learning to extract energy from the atmospheric flows, shaping and changing how they move and where they go," explains Kamran Safi, research group leader at the Max Planck Institute in Konstanz.
The relationship between age and use of the landscape can have implications for wildlife management practices. "We depend on wildlife distribution and movement maps to mitigate human-wildlife conflicts" says Nourani. "Our study suggests that such maps should be viewed as dynamic, changing across various factors, including age." This insight will enable more accurate predictions of potential overlaps between human activities and eagle behavior, particularly their use of the landscape at different stages of their development.
