It is uncommon to find carvings of this zun form, which originated in Shang dynasty (12th-11th century BC) bronze wine vessels, being replicated in jadeite. The shape itself appears to be faithfully copied in the raised flanges and the geometric carved design on the sides of the body. For two examples of this unusual model which appears to be a fusion between an owl and an eagle, both cast in bronze, see R. Bagley, Shang Ritual Bronzes in the Arthur M. Sackler Collections, vol. 1, Washington D.C., 1987, p. 406, no. 72; and another bird-form vessel with a gold inlay inscription: 'The gentlemen commissioned this bird for amusement', dated to the Eastern Zhou, circa 5th century BC, illustrated by W. Hung, Monumentality in Early Chinese Art and Architecture, Stanford University Press, 1995, p. 73, fig. 1.77.
A gemmological certificate from the Hong Kong Jade & Stone Laboratory Limited confirms the present lot is natural green jadeite.