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A green band reading

April 2024 Eagle Cam Update

“This is the business end,” says biologist Kathy Clark, carefully unwinding some bright orange protective wrapping from the big, powerful talons of a Duke Farms eaglet. The eaglet, the younger […]

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Apr 26, 2024

"This is the business end," says biologist Kathy Clark, carefully unwinding some bright orange protective wrapping from the big, powerful talons of a Duke Farms eaglet. The eaglet, the younger of two chicks hatched in the Duke Farms nest this year, is about to receive a green band numbered H44 on his left leg. But first, he's undergoing a physical exam by a team of state biologists and a veterinarian led by Clark, chief of New Jersey Fish & Wildlife's Endangered and Nongame Species Program.

Weight, check. Blood samples—to look for environmental contaminants like pesticides and heavy metals—check. Wing feather measurements, check. Bill measurements, check. Leg and hallux (hind talon) measurements, check. Heart exam with a stethoscope, visual eye exam—check and check. Lisa Davies on the Duke Farms staff records the exam data on a clipboard as the team calls out numbers.

A group of scientists take measurements of a bald eagle chick.

The day is sunny and one of the warmest so far this year, with Virginia bluebells blooming, Pileated Woodpeckers and Belted Kingfishers calling across the Raritan River floodplain, and early season butterflies pausing on flowers and patches of mud for nutrients. Each of these species, and the Bald Eagles themselves, depend on a healthy floodplain forest ecosystem, which is why Duke Farms works hard to restore these precious wetland habitats.

Eaglet H44's bill and leg measurements indicate that he is a male. In raptors like Bald Eagles, males are smaller than females, and their sex can be determined at a relatively young age by features like bill depth, leg diameter, and the length of the claw on the hind toe. "He is definitely small—we knew he was a male right from the beginning," says Diane Cook, NJ Eagle Project Volunteer and official Duke Farms nest monitor.

And to the relief of the team on site, he appears perfectly healthy after a rough first few weeks of life in the nest: "I'm sure everyone who watched the Eagle Cam in the first couple of weeks is relieved to know that that second hatched chick, who was referred to as Little or Number 2, is in great shape. He was actually a little feisty when our climber went to get hold of him."

Now, he's H44, and while his examination and banding is proceeding on the ground, a professional climber is waiting 80 feet up in an American sycamore tree, where H44's sibling is still in the nest. In order to band eaglets, a climber ascends the tree to the nest and lowers one chick at a time to the biologists waiting below, after affixing a hood on the birds to keep them calm and wrapping up their talons. 

A green band reading "H44" is placed on the leg of a bald eagle chick.

When the chicks trade places and the larger, older sibling is examined, some on the team are surprised. "According to our measurements and exam, they both appear to be males," says Clark.

"The first hatch was a bit of a surprise. He's going to be a large male," says Cook, who had expected the bird to be a female based on its size and aggressive behavior in the nest.

One of the adult eagles circles high above the tree canopy a few times during the morning. At the conclusion of the process, biologists leave two fish in the nest with the eaglets to make up for any minor, temporary disruptions to their food supply that the exam may have caused (adults will return to the nest as soon as the humans depart).

Biologist Clark is pleased. "They both are in excellent health," she says. "They've got a good food supply. Fingers crossed, everything should go smoothly for fledging in the next 5-6 weeks."

"It doesn't get old. Every time is just the most special, amazing thing ever," says volunteer nest monitor Cook. "After watching them all season as closely as I do so I can report back to the biologists, it's really cool to get to meet them."

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April 26, 2024