Here is a robin’s nest, an unusual nest because it seems to contain what appears to be deer hair, a lot of deer hair. I found it at Westwood Hills Nature Center in St. Louis Park. The Birds of North America monograph on American Robin describes the typical nest made by this species: an outer wall of dead grass and twigs lined with mud, the cup finished with dead grass. The mud is said to be from worm castings. Occasionally, white paper, feathers, rootlets, and moss are added, according to the authors. No mention is made of hair. There are many deer at Westwood Hills. The bird apparently made use of available materials. I once watched a robin building a nest, a conventional nest with grass and mud. The bird shaped the mud by rotating its body in the cup, using its breast and stomach to spread the mud on the nest walls. I wanted to see the inside of this nest to know if a more conventional approach was taken with cup construction.