Readers of Walden will remember Thoreau’s account of chasing a loon across the surface of Walden Pond and his observation, “I rejoice that there are owls. Let them do the idiotic and maniacal hooting for men.”
Those passages grew from the close observations of birds he made in his Journal from 1837 to 1861. Thoreau once said his Journal could be called “Field Notes,” and most of it is devoted to descriptions of his daily walks in Concord, including descriptions of dozens of species of birds.
Henry David Thoreau’s younger sister, Sophia Elizabeth Thoreau (1819–1876), was a botanist, artist, editor, and abolitionist who worked as a teacher and managed the family’s pencil business. She significantly shaped her brother’s legacy to an extent that modern scholars argue was under-acknowledged by Thoreau’s early biographers.