Pin feather protective peripheral sheath, longitudinal barb ridges, and growth plates. Over time these barb ridges lengthen helically, branch to create barbs and barbules, and fuse to form the rachis or central shaft. Moreover, the barb plate further differentiate into hooklets and cilia, while the marginal and axial plate die to form the intervening space within the feather structure. During moulting, a bird may get careless and begin to chew at its feathers and might accidentally damage a blood feather. To prevent this, it is necessary that the bird is given chewing toys so that it does not chew at its own
Calamus Creek Bridge Calamus Creek Bridge The Calamus Creek Bridge near Maxwell, Iowa is a concrete Luten arch bridge that was built in 1905. At a cost of $900, it was built by N.M. Stark and Company, a firm which built several Luten arch bridges that are listed on the National Register of Historic Places (NRHP). The Calamus Creek Bridge was listed in 1998. It has a single span and a total length of . The NRHP nomination for the bridge asserts:Before the codification of bridge design in the state in 1913, Stark built perhaps hundreds of Luten arches throughout Iowa, in exclusive