There came a point when bison skulls began appearing in my life -- suddenly I had four in my studio, for various reasons, and they're usually not easy to come by. I began to keep one in my car, as I felt it would be good to have on hand for outdoor sketching. I discovered that there had been a birds' nest in the brain cavity; it was packed with twigs. Inside were two white feathers, which appear in the foreground of this painting. It moved me to think that more than one life had been lived within this skull: