Wildlife biologists researching potential conflicts with wind power turbines in Pennsylvania, USA, and curious about the origin and destination of Eastern Golden Eagles compelled Mike Lanzone and Casey Halverson to develop something better than satellite technology. The resulting high-frequency of location points gave a far better data set, allowing the researchers to better describe flight behavior.
The Eastern Golden Eagles are morphologically different than the western counterpart, potentially genetically distinct, although the grad students we have working on that initially didn’t really find any real significant differences. Some of the work that’s been done now kind of gives us some some hope.
But there’s a population that is nesting in Quebec. They nest in Labrador, too, but that population passes through the eastern United States. Years ago, the birds they got in Cape May made us think ‘Oh these are Western birds that are strays here.’ And it wasn’t until years later when I started picking up large numbers here in the spring moving north we asked ‘Where are these birds going?’
It wasn’t until the ’80s when some of these Golden Eagles were tracked in Quebec and these tracks going back and forth over eastern North America made me realized that there’s potentially a significant population of Eastern Golden Eagles.
Well, the problem was wind power development risk was coming. On these ridges in Pennsylvania, we were worried ‘What if there is a conflict?’ We didn’t know if there would be. But we wanted to study flight behavior.
So we used the existing technology to to really try to look at this. But the biggest problem was we were getting hourly position fixes, so trying to look at any kind of flight behavior was very difficult. So we did a quick analysis of the data that we had and figured out we pretty much have to put telemetry units on every single bird in the population to get the kind of data we needed. Less than a year later we had developed a small transmitter that could provide high frequency data.
And so here’s a sample track. These are actual data of two of our Golden Eagles moving through Pennsylvania. The darker tracks on the bottom are 30 second data tracks from our transmitters, and the gold and yellow are satellite. And with this, you just don’t have two data points, you actually see how birds are getting from point A to point B.
And this kind of revolutionized data collection and this was 10 years ago now. And so really now instead of data points that were widely scattered we can start to collect detail flight behavior of how Golden Eagles were using ridges and how they potentially were reacting with wind power development.