Habitat-Population Relationships 



The potential for increase in wildlife populations in ideal habitat 

 almost defies belief. In 1900, there were virtually no wild deer left in 

 Pennsylvania. The state's original deer herd had been destroyed early in 

 the 19th century by landclearing for agriculture, overgrazing, by destruc- 

 tive timber cutting followed by wild fire, and by unregulated shooting. 

 After the Civil War, with increased industrialization and the opening of 

 the West, thousands of farmers abandoned their marginal lands to move 

 to towns, gold fields, or fertile soils beyond the Mississippi. Behind 

 them, the forests, under protection from wild fire, gradually began to 

 reoccupy abandoned fields and homesites, creating the early-growth 

 forests favored by deer. 



Around the turn of the century, sportmen's organizations and the 

 Pennsylvania Game Commission purchased a relatively few deer from 

 other states and from private dealers, had laws passed to protect them, 

 and released them into habitat that changing land use had made ideal for 

 deer. Twenty-five years later, Penn's Woods held nearly a million 

 whitetails, almost twice as many as the available range could support 

 through winter. 



Potentially, a deer population can more than double every second 

 year. One doe can produce 15 or more fawns in an average life span of 

 eight years. If all her young and theirs survive to the same age and breed 

 as successfully, they would number 150 or more before her death. Many 

 animals — songbirds, rabbits, squirrels, quail and ducks, for example — 

 can increase at even greater rates. 



