The final paper

When we started the Ecology Alaska project back in 2012, one of our primary goals was to attach satellite transmitter backpacks to bald eagles to track their movements. From the massive congregation of eagles in autumn at the Chilkat River near Haines, AK, we hoped to document where eagles traveled after leaving, whether they returned to the Chilkat the following year, and where they spent their time between one visit to the Chilkat and the next. Armed with transmitters from several organizations and the support of more than 100 Kickstarter backers, we started the project in earnest, setting out trail cameras and capturing eagles to fit them with tracking devices.


Over the next several years we monitored bear behavior and worked to estimate bear population size along the Chilkoot River corridor, just on the other side of the mountains from the Chilkat. All the while, we tracked the whereabouts of the eagles we’d fitted with transmitters. The GPS locations of eagles can tell us a lot about their behavior, but general patterns of behavior are often hard to see unless we have information about their movements over several years. Fortunately, newer tracking devices can last several years, and the solar-powered transmitters we used on our eagles were no exception!


After years of data collection, we finally had enough information to work with, and were able to take a close look at how individual eagles used the landscape, and whether there were any general patterns in the ways that all the eagles we tracked moved collectively. The results from our work have recently been published in the journal Movement Ecology.


We found that eagle movement throughout the year seemed to differ among individuals based on age, sex, and breeding status. Breeding eagles, for example, don’t move much throughout the year, and instead stick close to their nesting sites. Some non-breeding adults also didn’t move around much, while others migrate southward in autumn and northward in spring to separate winter and summer ranges. Immature eagles seem to have no idea what they’re doing, and move around from place to place throughout the year as nomads.


This paper represents the culmination of many years of research and effort, and is the final publication produced from the work of the Ecology Alaska project. As with all our publications, the journal Movement Ecology is open-access, meaning you can read our new publication for free. Check out our final paper here to see what we learned about eagle movement in the north Pacific.

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