The vignette appears in the first edition (1797) of the Land Birds, p. 147. Bain notes that Jane Bewick's manuscript identified the subject as a boyhood friend of Bewick's. Bewick is himself portrayed across the distant field behind a hedge. Liddell apparently used the tail of his coat to protect the gun's flintlock from the damp. The transfer drawing is at the Natural History Society of Northumbria.
Bibliography: Bain I, 161.