I found today two species of owls in the same park on Bucaramanga, Colombia. Black and whites on top image, spectacled on bottom image. They are not the same picture!
Now I know better tools. A graphite pencil or mechanical pencil will do equally fine, and you could use watercolors or acrylics. Also a regular or kneaded eraser will be needed. ( optional , if it is very hard for you to paint, photograph the bird and paint it in a more comfortable place. Also check the nature journaling course.