In the still life gallery at the Ashmolean Museum in Oxford, England sits an unassuming painting of a duck, an oil-on-work work by Dutch artist Aelbert Cuyp (1620–1691). It is the portrait of Sijctghen the Duck, one of the most beloved animals of the 17th century. Sijctghen laid more than a hundred eggs each year and was much treasured by her owners. They loved her so much that, in 1647, when she was 20 years old, they commissioned Cuyp to paint her portrait. The finished work contained a Dutch poem,…