Downy Barbules

I picked up this beautifully soft and downy feather in MA last week - it's most likely from an owl, since they have downy barbules on the sections of feathers closest to the body.

The barbules help reduce the sound of turbulent air rushing through its wings as it hunts, and also traps a lot more air for heat regulation.

World of Owls was a most helpful resource for this post.