LOUISVILLE State Department of Environmental Conservation officials say a necropsy of an immature bald eagle found dead along the Grasse River indicates it had been attacked by another eagle.
A Massena-area couple out for a hike found the dead eagle. They suspected the bird had been shot, which is a federal offense.
The cause of death was unknown. He relayed the eagle to me, and I sent it on to our pathology lab in Delmar. The lab determined that the eagle was killed by a conspecific, or one of its own species, said DEC principal fish and wildlife technician Blanche E. Town.
Ms. Town said data based on laboratory submissions show approximately 4 percent of eagle deaths are caused by another eagle, making it relatively uncommon. She said the dead eagle was determined to be a 2-year-old female.
Female bald eagles are larger than males. Eagles develop their size in the first year, but progress through various color phases of mostly brown with white mottling until attaining the dark brown body and distinct white head at the time of maturity, around the age of 5, she said.
She said eagles are territorial, but during the winter months it is common for them to forage and roost communally.
Bald eagles may live more than 30 years, but 15 to 25 years is their normal lifespan in the wild.
She said the bald eagle population is growing in St. Lawrence County.
It mirrors the growth we have experienced in the north country, the state and the northeastern United States, Ms. Town said, Breeding eagles are well dispersed throughout the county. They typically nest in mature forests near lakes, rivers or wetlands.
Ms. Town said sightings of the bird are common in the early spring, and the St. Lawrence River is the second largest wintering area in the state.
Birds from northern Quebec and Ontario migrate here to winter, she said.
She said eagles that winter on the Hudson and Delaware rivers also move through the area as they head home to Canada, temporarily swelling the north countrys population.