It seems like there could be more to the Sheldon Duck story than we have not heard before.  There is folklore about the feathered fowl.

The Sheldon Duck – in 1610, so legend has it, a group of Sheldon villagers watched a duck fly into an ash tree. They were baffled however, as they never saw the duck come out again. Thereafter, the tree became known as ‘The Duck Tree’. Nearly 3 centuries later, when the tree was felled and split up into planks in a timber yard in Ashford, the image of a ‘duck-sized’ pattern was found in the grain of the two middle planks, with markings where the brain and lungs would have been. Thus was born the legend of ‘The Sheldon Duck’. The two boards were on display in Ashford Post Office for a while, and postcards showing an image of the duck used to be sold. However, this was not to last, as the timber merchant who felled the tree liked the pieces of wood so much that he used them for making a mantlepiece at his home.

Source: Genuki – https://www.genuki.org.uk/big/eng/DBY/Sheldon/#Folklore

Now you know the legend of the Sheldon Duck, and why Sheldon Genealogy has a duck on its logo. and there are duck feet throughout the website.  If we place all of us in a large carton, we could easily be known as a box of quackers, I suppose.