The transfer drawing is at the Natural History Society of Northumbria, #44. The bird was mentioned in the text of editions prior to that of 1805 as the Least Willow Wren. In subsequent editions the bird is mentioned at the Least Willow Wren (Chiff-Chaff). In 1826, when the engraving was first published, the bird was named as the Chiff-Chaff. The Least Willow Wren was identified as a different bird.