in Thoreau’s Journal:

Saw my white-headed eagle again 1st at the same place the outlet of Fair Haven Pond. It was a fine sight— He is mainly––i.e. his wings & body––so black against the sky––& they contrast so strongly with his white head & tail.

He was first flying low over the water; then rose gradually & circled westward toward White Pond. Lying on the ground with my glass I could watch him very easily––& by turns he gave me all possible views of himself. When I observed him edgewise I noticed that the tips of his wings curved upward slightly the more like a stereotyped undulation. He rose very high at last––till I almost lost him in the clouds––circling or rather looping along westward high over river & woods & farm, effectually concealed in the sky.

We who live this plodding life here below never know how many eagles fly over us––