Nest Building Season
Late fall is the time of year when many birds of the Cascade Loop are building nests in anticipation of raising families in the spring. We were fortunate to watch a pair of golden eagles in the process of carrying field grass to a rocky cliff to build their nest over past weeks.
Eagles can be found in every region of the Loop, and winter migration can bring hundreds of birds from Alaska to the local river valleys, like the Skagit, Methow, Wenatchee and Columbia. Depending on the year, migration usually begins in December, and the Skagit Valley Eagle Festival runs weekends in January. When snow begins to melt, most of the eagles head back north, but occasionally a pair will build a nest and set up residence – which can be a wonderful opportunity to observe these magnificent creatures. Of course, nests in residential areas can be a concern for small pet owners.
Golden eagles are great hunters, and do not like carrion, but bald eagles have no qualms taking kills from other birds and animals (and even fishermen).
Golden vs. Bald
Bald eagles are not actually bald. Adult birds have white feathers covering their heads, and their tails feather are also white, while their bodies are very dark brown, and look black in certain light. Juvenile bald eagles can be tricky to identify if you are in a region that also has golden eagles. The easiest way to tell a juvenile bald from a golden eagle is to look at their feet. Golden eagle legs are feathered to their foot, but bald eagle legs have no feathers. Another identifier is their beak – a bald eagle’s beak is very large, almost a third of his head, where a golden eagle’s beak is more proportional to their head, making the head look shorter compared to a bald eagle.
Juvenile bald eagles are entirely light grey fluff when hatched, and over the next five years their coloring gradually grows more mottled and white on their bellies, until they become adults with white heads and tails. While they are young, bald eagles beaks are dark, but adults have all yellow beaks.
Golden eagles are dark from juvenile to adult, with some white feathers on the underwings and at the base of their tail. Adult golden eagles are brown with tawny on the back of the head and neck and their tail is faintly banded.
Both bald and golden eagles mate when they reach adulthood - 5 years and 4 years respectively – and both species stay paired with the same mate for life.
Bald eagle nests are usually found high up in trees, preferring dead snags. They will use sticks, grass, feathers, and even moss and cornstalks.
Golden eagles prefer to nest on rocky crags or notches in cliff faces, and often return annually to the same nest.
The female will lay one to three eggs, which will need to be incubated for 34-36 days (bald) and 41-45 days (golden). The male will bring food to the female while she sits on the nest, but both parents share duties of raising the young.
Learn more during the Skagit Valley Bald Eagle festival every January. Activities take place in Concrete, Rockport and Marblemount every full weekend in January.
