Banding the Duke Farms Bald Eagles

On April 10, 2025 our official Nest Monitor with Conserve Wildlife Foundation of NJ joined biologists from the New Jersey DEP Endangered and Nongame Species Program in the field to band the eagles at the Duke Farms Bald Eagle Nest and shared her experience with us.

The Duke Farms eaglets were banded! The weather was perfect in the morning, sunny and not too warm. I have seen many questions regarding banding, and will try to answer each. Photos are mine taken during the day, as well as a few screenshots of the cam once I returned home.

Parents’ behavior during banding is a question I saw pop up many times. As the team began our walk to the nest, I scanned the sky for adults. I spotted one at a great distance perched above the river on a tree.

As we reached the nest area, an adult vocalized and then flew from the nest tree. It was hard to see which adult it was, but it continued circling the nest area and vocalizing.

The team reached the nest tree, and preparations began. The tree climbers prepare for a safe climb at the tree. The long climb begins, first one then the other. The nest sits 80 feet off the ground. You can see the cam above and slightly right of the first climber.

Both adult eagles continue to circle the area very high in the sky. We could hear them vocalizing during their fly-overs. I have read that due to their large size, bald eagles are not quick and agile enough to take on something larger than themselves. Their size makes it difficult to escape quickly, and they do not put themselves in danger taking on something like people. You can be sure they are watching though!

As the first tree climber reached the nest, an adult could still be seen flying high above (center of the red circle).

Meanwhile on the ground the banding area has been set up. Measuring devices, bands, and items needed to take blood are all laid out on a blanket that has been spread on the forest floor in a shady area.

Bands - green for easy spotting and identification as a NJ bird. Silver is a long number and is the federal band.

Once the climbers are in place and the ground crew is ready, the first eaglet is caught. The climber does not seek eaglets in hatch order. He gets the first eaglet that is closest to him. They tend to move to the opposite side of the nest, and huddle together. This is one reason the team aims to band eaglets at 6 weeks of age. They are easier to handle and are not likely to jump from the nest. The eaglet's talons are wrapped to protect everyone, and a falconer’s hood is placed over the head to calm the bird. It is then placed in a canvas bag and slowly lowered to the ground. The bag and eaglet is weighed. The weight of the bag will be subtracted to get the bird’s weight.

The eaglet is taken from the bag, held by a team member, and the process begins. Measurements are taken, recorded on a data sheet, and studied by the professional team. These measurements are compared with those of research tables/charts to determine the probable sex of each bird. H57’s numbers strongly indicate he is male. Based on behavior observed in the nest from hatch and after banding, and by measurement of his 8th primary feather, it appears he is the former E3, 3rd hatch.

H57’s 8th primary feather is measured. The straw-like objects are a thin tissue covering the developing feather. It is filled with blood to nourish it. As the feather grows, the covering dries up, falls off, except close to the body, and a beautiful dark feather is unfurled.

H57 has his bands, gets a check up from the state’s vet (just like your physical: eye check, a look down the throat, listen to the heart), and placed back in the bag for the ride back to the nest.

H57 has his bands, gets a check up from the state’s vet (just like your physical: eye check, a look down the throat, listen to the heart), and placed back in the bag for the ride back to the nest.

As soon as the bag on the next eaglet is open, it is clear this is the first hatch and female. H58 is huge! The procedure is repeated for each eaglet. Blood taken, measurements, bands, and checkup before returning to the nest.

H58 is banded. Green bands are placed on opposite legs in nests with 2 eaglets. This helps monitor to know who fledges first. In a nest with more eaglets things are a bit tricky. Since H58 is a large female and H57 a smaller male, the green band is on the same leg. If size holds up, it may be easy to see which of these 2 fledges first. The middle eaglet’s band is on the right.

She’s a big girl, and she made it clear how she felt about her experience. As she was lifted off the blanket for her trip back to the bag and nest, H58 left a present on the blanket and the team’s vet!

She’s a big girl, and she made it clear how she felt about her experience. As she was lifted off the blanket for her trip back to the bag and nest, H58 left a present on the blanket and the team’s vet!

H59 was last to be banded, and is a mystery. Based on behavior observed all season and after hatch, coupled with the length of the 8th primary feather, this is hatch 2. As for whether H59 is male or female, this eaglet was unclear. Numbers will be studied more and compared with the research tables and charts.

When all was done, H59 rode back up to the nest along with a bag of 6 fish. During banding, the adults continue to fly over the nest, vocalizing to let us and their offspring know they are near. In the last hour the adult activity settled down, and they were out of our view. Fish are left in the nest so when the parents return, there is something to eat without having to hunt for the meal, making for a stress free return to normal life.

All 3 eaglets self-fed on the fish as seen on the live cam when it came back online following banding, and continued until an adult returned. An adult off cam view could be heard vocalizing beginning about 2pm, and the eaglets could be seen tracking something above them.

Just after 4:30pm, the female came down to the nest. The eaglets all began talking at once. Were they telling her stories of their crazy adventure. She looked around the nest at all the fish. Was she wondering where they all came from?

After an eventful day for the Duke Farms eagle family, the 3 eaglets settled down with their mother.