To tag an eagle!

Preparation

This is Duke. He is a juvenile Black eagle, now just over a year old. He was raised in the wild but on fledging (or floating) from his nest he never flew again. He does not have a tail; some sort of genetic mutation probably caused this. In the wild he would never have survived. Now he is now cared for at Eagle Encounters and has recently become a vital part of our team too.

For the last few months I have been visiting Duke regularly to set GPS harnesses on him. He is pictured here with a hood to cover his eyes and reduce stress while I am sewing the link into a harness, which is designed so that it can fall off. Getting this process right is critical to the survival of any wild eagle that we tag. The opportunity to work with Duke has been vital in my learning and it has given me the chance to monitor the comfort of an eagle wearing a harness. Somehow it also seems to fulfill a purpose for his flightless life.

Trapping

Lucia Rodrigues, Patrick Banville and myself set out this morning to catch one of the eagles which falls within my study. Having set a trap before sunrise the long wait was on. By 11:00am the eagle pair were going about business as usual without any apparent attention to our trap. Other plans were hatching in our minds when a Booted eagle landed in front of the three of us. Instantly transfixed by the proximity of this Booted we took our eyes off the Black eagles. Black eagles in my mind are cunning and very much aware of our actions in general. We often joke that they are watching us and waiting for us to pack away a telescope or start a walk home before they will fly off a cliff. So it was typical Black eagle fashion when the moment we three raptor enthusiasts diverted our eyes (and binoculars) the Black eagle made a dive for our trap! Within a moment we had caught the eagle and raced towards it.

Now the time had come for the real thing. The eagle was magnificent. It is the male of a breeding pair. Males are smaller than females but this bird still had a 2 meter wingspan and weighed in at 3.2 kilograms. This is the second Black eagle that we have tagged for the project. However, the previous GPS came off prematurely after only 5 weeks. 

The harness went on smoothly and we weighed and measured the eagle before releasing it again on site. For me this was the most nerve-wracking moment. I double checked everything I had done and then we watched as the eagle flew away. It was soon to reappear with its mate on the nest cliff and we will now be closely monitoring this bird and regularly downloading data. This is a really important step in the research and I am sure it will bring some new insights into the behavior of Black eagles.

Now that it is all done and the reality of what we have achieved today is sinking in I would like to give a big thank you to the team and to Victor Garcia (Spanish Ministry of Environment) and Hank Chalmers (Eagle Encounters) for plenty of prior help and advice.

After the event we enjoyed a Black Mist (beer inspired by the Verreaux’s eagle) courtesy of Darling Brew. Cheers folks.