GPS tracker on wedgies gives us a bird’s eye view

“Tracking technology can give us an understanding of where they like to perch, whether they like to fly long distances and help guide us on how to protect different habitats,” Dr Pay says.

Researchers attached the tracking devices between the birds’ powerful wings, often scaling huge trees to reach the fledglings in their nests.

The small square boxes, which weigh only 65 grams and are powered by solar energy, are held on by soft Teflon straps in the middle of the bird’s back, with the weight distribution as close to their center of gravity as possible.

Eagles fly without using much energy by relying on thermal soaring — using rising pockets of warm air to gain height. For example, an eagle called Ethan rose to 600 meters above ground level in just eight minutes, gaining height about two meters a second.

The data showed that when young eagles are perching or on shorter flights, they love to spend time at the edges of native forests, where they meet grassland or pasture.

On longer flights, they float up on thermal air currents and their location is less specifically associated with certain habitats.

The tracking also allows researchers to study a behavior known as dispersal, where immature birds travel long distances across Tasmania after leaving their parents.

Dr James Pay releases MaluCredit:Jason Wiersma

It revealed that young birds stayed with their parents for far longer than expected, some for about a year. When they leave, they spend a few years flying around Tasmania until they settle.

Researchers expected about half of the 25 eagles to die in their first year after leaving their nest but happily, all except two survived.

Dr Pay is now using the same method with adult birds, to get a better understanding of their habitat use. The trackers will continue to transmit the birds’ movements for up to five years.

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