Road Density

In regions inhabited by both wolves and humans, the later are often the overwhelming factor in the former's mortality. Highways, freeways, streets, and dirt roads, in one way or another, are often man's accomplice in this matter. In Canada, Alaska, and northern Minnesota there exists a distinct, inverse correlation between road and wolf density; in other words, more roads mean fewer wolves.

Roads are hazardous to wolves for two reasons. First, roads open up the back country to human intrusion and make it easier for hunters and poachers to kill, maim, or otherwise disturb wolves. Furthermore, logging, homesteading, and other human activities potentially destructive to wolves and their habitat often follow the bulldozer and steam roller into the forests. Second, roads are paths by which three-quarter ton projectiles--deadly to wolves and other wildlife--careen through the countryside taking out unsuspecting and/or confused animals. In some areas, wildlife biologists estimate that wolf-automobile 'encounters' account for nearly 30% of wolf mortality.

The US Fish and Wildlife Service has determined that the road density threshold for long-term wolf survival in any given area is approximately one mile of road per mile squared of habitat. Therefore, in considering prospective release sites, the Fish and Wildlife Service recommends that only those sites with road densities below this threshold be considered for wolf release.

Using GIS, I calculated the road density of the Big Bend Wolf Recovery Area...

The steps involved in creating this map are as follows::

The total area of parksbuff is 7,191 square miles. The total length of paved and unpaved roads within parksbuff is 579 miles. The road density is thus .08 miles of road per square mile of habitat, well below the USFWS-recommended threshold.

Problems with the Analysis

While working on the roads segment of this project a number of questions came to mind, including:

Additionally, there is one significant problem with my analysis. Though the Mexican portion of the Big Bend Wolf Recovery Area is sparsely settled, there are a few people living and working in the area. Likewise, there are a few roads. These roads will have to be included in the dataset to improve the accuracy of my calculation.