Habitat loss—due to destruction, fragmentation or degradation of habitat—is the primary threat to the survival of wildlife in the United States. When an ecosystem has been dramatically changed by human activities—such as agriculture, oil and gas exploration, commercial development or water diversion—it may no longer be able to provide the food, water, cover, and places to raise young. Every day there are fewer places left that wildlife can call home. There are three major kinds of habitat loss:
* Habitat destruction: A bulldozer pushing down trees is the iconic image of habitat destruction. Other ways that people are directly destroying habitat, include filling in wetlands, dredging rivers, mowing fields, and cutting down trees. * Habitat fragmentation: Much of the remaining terrestrial wildlife habitat in the U.S. has been cut up into fragments by roads and development. Aquatic species’ habitat has been fragmented by dams and water diversions. These fragments of habitat may not be large or connected enough to support species that need a large territory in which to find mates and food. The loss and fragmentation of habitat make it difficult for migratory species to find places to rest and feed along their migration routes. * Habitat degradation: Pollution, invasive species and disruption of ecosystem processes (such as changing the intensity of fires in an ecosystem) are some of the ways habitats can become so degraded that they no longer support native wildlife.
What are the main drivers of habitat loss in the U.S.?
* Agriculture: Much of the habitat loss from agriculture was done long ago when settlers converted forests and prairies to cropland. Today, there is increasing pressure to redevelop conservation lands for high-priced food and biofuel crops. * Land conversion for development: The conversion of lands that once provided wildlife habitat to housing developments, roads, office parks, strip malls, parking lots and...