Bald eagles seek out nesting materials that will insulate and cushion their eggs. Once the eggs have hatched, the nesting materials help keep the baby birds close together. The chicks require especially durable nests because of their playful nature. Unlike other bird species, bald eagles can maintain their nests for decades. They prefer to build them close to large bodies of water because of the abundance of fish.
Twigs and Sticks
The majority of a bald eagle's nest is made of sticks and twigs that range from 9 to 98 inches long and .12 inch to 2 inches in diameter. Both female and male bald eagles gather the sticks used to build their nest. They layer the sticks to make the nest sturdy.
Moss and Pine Needles
After the nest has been built with sticks, bald eagles start looking for softer materials to make it more comfortable for their eggs. Because they build their nests close to water, moss and pine needles are often available for extra padding.
Feathers and Grasses
Bald eagles next add insulating materials to the nest, including their own feathers and stems of grass, during each breeding season.
Over time, bald eagles have discovered new forms of man-made nesting materials. These materials include cellophane and plastic insulation. By examining the cellophane and plastic insulation, scientists can determine how long the eagles have been using their nest. One bald eagle nest was believed to be at least 36 years old.