Nesting instinct. Nesting behaviour refers to an instinct or urge in pregnant animals caused by the increase of estradiol (E2) to prepare a home for the upcoming newborn(s). It is found in a variety of animals such as birds, fish, squirrels, mice and pigs as well as humans.
Nest, eggs and young. Like the Osprey and the Bald Eagle, the Golden Eagle is a champion nest-builder, at least in terms of size. Golden Eagles construct a huge platform of sticks, which they line, or pad, with thinner branches and even hair and grasses.hese large birds sometimes build their nests in trees or might use man-made structures, such as an electricity pylon. In Alaska, some Golden Eagles were documented nesting on the ground., but most often they nest on large ledges on cliff faces. Golden Eagles may use the same nest over many breeding seasons.
They may desert one nest site and start again somewhere else, usually within 1/2 mile. A northern bald eagle will begin to nest sometime in February or April. A southern bald eagle will begin to nest in December and January Each nesting pair will spend a great amount of time preparing the nest before any egg is laid. The successful nest is generally located in a large tree, within one mile from water, either a lake or river, where adequate food is available. Bald eagle nests are generally found from 15 to 36 meters (50 to 120 feet) above the ground, in a tall, sturdy tree. It takes at least two weeks for a pair of eagles to build their nest. A typical bald eagle nest (eyrie) will range from 1.8 to 3 meters (6-10 feet) in diameter and about 1.8 to 3 meters (6 to 10 feet) high. The nest cavity, where the eggs are laid, will be about 30 to 40 centimeters (12 to 16 inches) in diameter and about 10 centimeters (4 inches) deep. A pair of eagles, once established, may use the same nest several times over a period of years.