May 20, 2007 - Weaving Stacks Welcome to the Nature Notebook. Weaving a hanging sack is an intricate undertaking, especially if you don’t have hands. But the Baltimore Oriole is up to the task. Using its beak, the female oriole carries one long fiber at a time to the drooping tip of a twig. Hanging on to the bobbing twig with her feet, she secures the first fibers, forming a loose framework. Into this she weaves additional strands of grass, grapevine bark, milkweed stems, thread, or yarn. Once the outer walls of this hanging hammock are complete, the oriole begins on the interior. Here she switches to softer materials, shaping the hanging sack with her body and finally lining it with soft, downy fibers that will cushion and insulate the eggs and hatchlings. The several day process produces a one-use, woven nest that makes a fine cradle for young orioles. This is PPL's naturalist, Jon Beam, with the Nature Notebook for WVIA.