These two hand colored French engravings, which I believe were published 1770-1786, came from the (title in English) Natural History, General and Particular, with a Description of the King's Cabinet, a collection of 36 large volumes written between 1749 and 1804, and continued in eight more volumes after the death of the original author.  These books are very well-known, and much information can be found about them.

The engraving on the left, the plate numbered 426, is of a bird known in English as the turkey vulture, or turkey buzzard, or just buzzard.

The bird in the engraving on the right, the plate numbered 416, is a medium sized bird of prey in the same family as eagles, buzzards and harriers, and known as the red-backed sea-eagle in Australia.

I have found selling offers for plate 426 ranging from $195 to $350, and similar asking prices for plate 416.

My late mother bought these two engravings in England in the mid-1950s.  When she bought them, they had been minimally framed by sandwiching them between a sheet of ordinary glass and cardboard, neatly held together by black cloth tape.  Since then, the tape has deteriorated to the extent of no longer holding together on plate 426; the tape on plate 416 is still holding, but deteriorated.  Plate 416 is about 12-1/2 inches by about 9 inches; Plate 426 has been shortened by about an inch in height and about a ¼ inch in width.