Today I listen to a talk given by Dr. Gary Tabor, the Executive Director for the Conservation for Large Landscape Conservation. The lecture focused on efforts to conserve wildlife habitats in North America, especially focusing on the west coast and Colorado Basin. One of the most interesting things Dr. Tabor talked about was the efforts we are making to help animals cross large highways and roads. According to Dr. Tabor, roads, highways and railroads can be extremely detrimental to wildlife habitats because they cause a divide in the habitat over which animals are either unable, or too scared to cross. One of the ways we help animals to cross these man made boundaries is by creating land bridges or underpasses. These passages allow animals to cross boundaries and access parts of their ecosystem that would otherwise be cut off. Below is an example of one of these land bridges:
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While these bridges are a very inventive and effective way of maintaining habitats for wildlife, they are not a final solution to the problem. While they do seem to provide a safe way of travel for animals, they can sometimes become a bottle neck for these animals, where they may run into other animals. This can result in conflicts between animals that would never has arose had there been no bottleneck. In the lecture, Dr. Tabor showed a video of two bears who met on one of these bridges. They immediate began to attack each other.
These bridges also have one other, extremely obvious, flaw: some animals might not know where they are. Animals a few miles away from the bridge may be forced to cross the highway without ever knowing there is safe way to cross just minutes from them. The only way to fix this problem is to build many bridges all down the highway. Given the amount of highways, in America alone, that cut through endangered wildlife habitats, the cost of this project would be astronomical. Therefore it will be neccessary to find another way of getting these animals across major boundaries.
