Birds and Branches, Delicate 19th C. Pen and Ink Drawing in Period Frame

I'm always tempted by Spencerian drawings of birds, found on Victorian calling cards and in autograph albums, but this one, rendered in red and black ink, is earlier than most of those, and how lovely perched on exuberantly branching, delicately leaf dotted branches in dark green, with sprig in beak, too. Plus this awkward, second partial one with a very eagle-like eye at bottom! Cut down/salvaged from a larger drawing or page at some point I presume, and mounted to backing card. I thought special enough to honor with a nice gold gessoed period frame, a small gem of a thing. 

Frame, with early/original thick, hand-cut glass: 7 13/16" x 5 13/16". Drawing, which at some point was mounted to card: 5 1/8" x 3 1/2". Not a fancy framing job--I just mounted it with archival tape to archival mat board and backed with another layer of the same. Easily removed. (The frame itself is a great one and I know from searching how hard to find ones of this size!)