I finally got one! My first Cayuga duck egg. I bought an assortment of ducklings and goslings from @cacklehatchery last year, and after having recently moved them into the chicken coop which has lights to extend their 'daylight' hours, I found a duck egg.
I repurposed this old shelf into a flower bed this morning. I covered the bottom with cardboard, hauled in some dirt and transplanted some flowers.