Designing Nature Reserves: past, present and future.
To begin Dr. Craighead's talk you can click here or read this brief overview, below, that provides links to the best places in the talk for specific topics.
Most biologists will agree that we are in the midst of another period of extinctions. We don't know how extensive it will be relative to previous events, but it is qualitatively different due to the fact that it is primarily caused by human beings. One of the ways we may be able to reduce the magnitude of extinctions is to provide refuges where species are buffered from the factors causing extinction. This is becoming the unstated goal of nature reserves - refuges from extinction. Originally some of the reserves were private hunting preserves for royalty.
One method for maintaining and tracking biodiversity in an area is to use umbrella species - one whose habitat encompasses the habitat needed by a large number of other species. The Grizzly Bear is an example. If we can maintain a population of Grizzlies, we will also be maintaining a large number of other plants and animals. How successful are we in protecting the Grizzly Bear?
First, early settlers killed Grizzlies often using firearms from Europe. Then humans began altering the habitat on a large scale by building cities, roads and introducing agriculture. This created areas of local extinction and isolated, small islands of bear populations. Currently there are only about 1,000 Grizzly Bears in the contiguous United States and they are located in four main areas designated as Grizzly Bear Recovery Zones by US Fish and Wildlife. One of our goals has been to study whether there may be dispersal routes with adequate habitat that permit Grizzly Bears to migrate between these core reserves.
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