Read "Boys Rob A Yellow-Hammer's Nest" at The Eldritch Dark:
http://www.eldritchdark.com/writings/poetry/63/boys-rob-a-yellow-hammer%27s-nest
As with the poem "Flight of the Yellow-Hammer" (which I blogged about last month), it seems that in "Boys Rob A Yellow-Hammer's Nest", Clark Ashton Smith (CAS) is referring to Colaptes auratus, the bird commonly known as the "northern flicker".
It's not a great poem from CAS, but as part of his "Childhood" series of haiku, it definitely captures a spirit of youthful adventure in the natural world that reminds me of my own boyhood.