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.
Red-bellied Woodpecker. Woodpeckers belong to the family Picidae, which also includes sapsuckers and flickers. More than 300 species of woodpeckers are known throughout the world, and 22 species inhabit the United States. Seven species are common to Pennsylvania, and a few others visit the state in winter.