Who is that eagle with a transmitter?

We started to get reports in January of an eagle with a transmitter near Lock and Dam 14, which stretches across the Mississippi river between Le Claire, Iowa and Hampton, Illinois. Like most large lock and dam systems, LD 14 has open water even in the coldest weather, making it a popular place for wintering bald eagles. Of course wintering bald eagles attract photographers, and some of those photographers noticed that one of the eagles had a transmitter on its back. Could this be D1?

Eagle ACE, photo credit Ted Thousand

A few things about the eagle: it was a mature adult, its backpack had no antenna and a clearly visible ID number, and it was left leg-banded. Our transmitters have an antenna and Brett tends to band the right leg, not the left (he made an exception for D25 this year in the service of easy ID). Brett suggested I talk with the Rock Island Fish and Wildlife Service to see if they knew anything about it. Bingo – they did!

Sara Schmueker is a USFWS biologist. She told me that mystery eagle #35959 is part of a Midwest Bald Eagle telemetry study conducted by the U.S. Fish and Wildlife Service, West Virginia University, and U.S. Geological Survey. He is nicknamed “ACE” because he was caught right outside the Army Corps of Engineers – Mississippi River Project Office below Lock and Dam 14 in January of 2016, when he was six years old. ACE summers up in Ontario, Canada – not too far from some of the eagles Brett is studying – and winters at LD 14. Let’s take a look at his map!

ACE's Travel Map
Two things stood out for me. Firstly, ACE’s trip through Wisconsin is remarkably similar to some of D1’s trips and fits the model we proposed here: https://raptorresource.blogspot.com/2016/11/where-did-all-these-eagles-come-from.html. Secondly, ACE’s trip appears to have brought him near to the North Nest area, if not exactly at the nest. Sara told me that around 30 eagles are currently carrying units for this study. Had some of them gotten even closer? I decided to check the study’s web page at https://www.fws.gov/midwest/rockisland/eagle/telemetrystudy.html to find out!

The answer to the first question was ‘Yes’! Several eagles had passed directly through the area of the North Nest, which is a sort of bottleneck for eagles on the west side of the river, based on the map. I was also amazed by the flights of what I am going to call the Yellow and Blue eagles, which flew from East Central Iowa all the way up through Nunavut to the Beaufort Sea. According to Google Earth, this is a straight-line distance of over 1800 miles – and neither of these eagles flew in a straight line! And finally, a few of these eagles appear to have passed by Eagle Valley on the east side of the river. I like to think that Brett could have spotted them on one of his observational trips, even if he didn’t see their transmitters.

Sara told me that team has an end goal of 50 or more eagles with transmitters, which will each provide about five to six years of data to inform management and conservation of the species. Their partners include some names that will be familiar to our followers: the American Eagle Foundation, Alcoa, ITC Transmission, MidAmerican Energy, the Avian Power Line Interaction Committee, the American Wind and Wildlife Institute, FWS, WVU foundation, and the Peregrine Fund. This is a fascinating project and I really encourage people to go to the FWS website to learn more about it. Again, the address is https://www.fws.gov/midwest/rockisland/eagle/telemetrystudy.html.

A huge thanks to everyone who contacted us about this eagle – it was very interesting to learn about and helped make some great connections! Another huge thanks to Sara Schmueker for her study and the information she provided. Bob would have found this absolutely fascinating. Please stay safe, D24 – we want to know what you do this summer!

We suspect that some people are wondering why our platforms use antenna given that ACE’s platform doesn’t have one. While we don’t have details for all of the eagles in the FWS study, ACE is wearing a cellular platform that uses the same spectrum a cellular phone does. Our eagles are wearing satellite platforms that use a different spectrum, as described here: https://raptorresource.blogspot.com/2016/08/eagle-tracking-can-you-do-something.html. There are advantages and disadvantages to each system: the cellular platform doesn’t require an antenna, but only provides data in areas that have a cellular connection. The satellite platform provides data from everywhere, but requires an antenna. We are continuing to research tracking technology as the technology advances so we can make the best decisions for the health and safety of our bald eagles.