Trumpeter swan

By the early 20th century, the species had nearly disappeared from the contiguous United States.

Around 1930, approximately 70 trumpeter swans remained in the greater Yellowstone ecosystem, including Yellowstone National Park, in what is now Red Rock Lakes National Wildlife Refuge, in southwestern Montana.

These surviving birds became essential to the species' recovery.

Wildlife researchers began documenting swans more carefully in the late 1920s.

That cygnet died a little later.

His observations highlighted the challenges facing the species and the importance of protecting its habitat.

Dixon also filmed the birds, producing footage later identified by the National Park Service as the earliest known motion picture of trumpeter swans.

There's something that I didn't know.