Betula papyrifera tree. The seeds of paper birch are an important part of the diet of many birds and small mammals including chickadees, redpolls, voles, and ruffed grouse. Yellow bellied sapsuckers drill holes in the bark of paper birch to get at the sap, this is one of their favorite trees for feeding on. The species is considered vulnerable in Indiana, imperiled in Illinois, Virginia, West Virginia and Wyoming, and critically imperiled in Colorado and Tennessee. "Betula papyrifera" has a moderately heavy, white wood. It makes excellent high-yielding firewood if seasoned properly. The dried wood has a density of and an energy
Northern celestial hemisphere referred to as the Northern Hemisphere. For the purpose of celestial mapping, astronomers may conceive the sky as the inside of a sphere divided into two halves by the celestial equator. The Northern Sky or Northern Hemisphere is therefore the half of the celestial sphere that is north of the celestial equator. Even if this geocentric model is the ideal projection of the terrestrial equator onto the imaginary celestial sphere, the northern and southern celestial hemispheres is not to be confused with descriptions of the terrestrial hemispheres of Earth itself. Northern celestial hemisphere The northern celestial hemisphere, also called the