Want a Nut? Adult male acorn woodpecker (Melanerpes formicivorus) holds an acorn, ready to store it in a granary tree. These birds live in large colonies, led by the alpha female. They store acorns in these granaries, guard them against other groups, and breed cooperatively. They are common throughout much of Jasper Ridge Biological Preserve. Males have red touching white, on the forehead. Females have black in between. This male is from the colony in the snag next to the Sun Docent Center, ready to put an acorn in storage. October 27, 2008 at 10:17 am. Jasper Ridge Biological Preserve.