act as the functional units of the respiratory system by passing oxygen into the body and carbon dioxide out of the body. Finally, the muscles of respiration, including the diaphragm and intercostal muscles, work together to act as a pump, pushing air into and out of the lungs during breathing.
The Ivory-billed Woodpecker (Campephilus principalis) is an extremely rare member of the woodpecker family, Picidae. It is officially listed as an endangered species, but by the end of the 20th century had widely been considered extinct until it was apparently sighted along the Cache River in Arkansas in 2004 and 2005.
The ivory-billed woodpecker ranks among the largest woodpeckers in the world and is the largest in the United States. The closely related and likewise possibly extinct imperial woodpecker (C. imperialis) of western Mexico is, or was, the largest woodpecker. Cuban ivory-billed woodpecker (Campephilus principalis bairdii or Campephilus bairdii), now believed to be extinct. 2  American ivory-billed woodpecker (Campephilus principalis principalis or Campephilus principalis), described here.