Wildlife Corridor Lab Project

Objective

The objective of this lab is to show the benefits of wildlife corridors, both to wildlife and humans. One of the effects of human expansion has been Habitat Fragmentation. Wildlife corridors, aided by Conservation Easements, will allow wildlife to be able to roam over greater areas without being encroached upon by human development. This will create Landscape Linkages that well help reduce unnecessary human/wildlife interactions, reduce inbreeding, and allow the bypass of manmade abiotic occurrences that cause impediment to movement by many native species.

Procedure

In Northern Arizona, the construction of several highways, and their expansion from 2 lanes to 4 lanes, have fragmented the wildlife habitats. This has lead to issues with many large animals having unfortunate interactions with humans. Northern Arizona is a diverse range of ecological zones, with a topography ranging from snowy mountain peaksalong with some areas that could be considered high desert. Ecotonal features include aspen-fir pine forests, to temperate grasslands, This wide range of ecological zones of course also leads to a wide range of animal species that use one or more of these zones as their natural habitat. The expansion of man has cut right through the middle of these zones, especially with freeway and highway construction, that often has no built in means of allowing wildlife to cross unimpeded. Highways 89N, 180, and 64 form a rough triangle that begins in Flagstaff, and loops northward to the Grand Canyon, with the San Francisco Peaks at the center. This triangle of highways encompasses an area of nearly 120 square miles, and causes a serious impediment to animals stuck within this triangle. These animals are trying to roam for food or mating reasons. Some species also need to migrate to warmer southern climates during the winter months.

Norther Arizona highways preventing wildlife migration.

Two of the species that I have chosen for the wildlife corridor project are Cervus canadensis, or Elk, and Ursos americanus, or the black bear. These species are two of the largest mammals present in Northern Arizona's mammal demographic and can be among the most disruptive when it comes to human and animal interactions. Both species have high spatial requirements, and would be considered umbrella species. Elk, which had originally been extirpated in Northern Arizona, but have since been reintroduced, have a range of 20-30 square miles, and must consume 15-20 lbs of vegetation a day. They prefer higher altitudes during the summer, and migrate to lower altitudes during winter months (http://www.azgfd.gov/h_f/game_elk.shtml). Black bears forage in areas up to 50 square miles, and prefer berries or grass, but will adapt to whatever food is available (http://www.azgfd.gov/h_f/game_bear.shtml).

While Elk are not normally a danger to humans, they are often times involved in vehicle accidents on highways. Elk can weigh between 600-1200 pounds, and can cause devastating injuries and damage to vehicles, not to mention the injuries or death of the elk involved.

This female elk is nearly the same size as the full sized truck.

Black bears are less commonly involved in vehicle accidents, but with human encroachment cutting down their natural habitats, they are becoming a nuisance in neighborhoods foraging for garbage instead of their natural dietary menu.

Both the Elk and Black Bear would benefit greatly from a wildlife corridor to alleviate current dangers to both humans and wildlife. With temporal access to wildlife corridors available to the animals, there would be a drastic reduction in vehicle accidents involving elk, and allow black bears to roam further as needed to sustain their dietary needs and mitigate forming a dependence on human garbage and waste. Going forward, the pre-existence of wildlife corridors free from human development and light pollution will allow for elk and black bear to continue to migrate and forage as needed, while marking clear areas where human expansion will be prohibited or severely limited. This will help to ensure the diversity of future generations of the species, as well as maintaining proper species birth rate with the genetic interchange provided by the wildlife corridors. While helping to maintain core habitats his will also help to ensure continued future safety for motorists and residents.

Results

Wildlife corridors would greatly expand the range of elk and black bears.

While it may not be possible to create wildlife corridors that are 1000 ft wide, as recommended by Monica Bond, it should be possible to mark off regions that are more than a 1000 ft wide, with multiple access areas. The most economically feasible way to do this with the existing highways would be the creation of culverts that pass underneath existing highways or wildlife overpasses that go over the highways. These would need to be created large enough and wide enough to allow these large animals through. Having several of the culverts or overpasses available in the selected corridor areas would be beneficial, as it would allow multiple herds of elk through, as well as allowing the elk the opportunity to avoid using the same paths as their natural predators. The culverts would need to be built in higher ground areas, to avoid the likelihood of flooding, and to avoid build-up of debris due to flooding that would block access to the culverts. Care would need to be taken to monitor possible blockages during winter months as well, as this would be when elk would be more likely to be migrating due to the weather conditions. Blocked culverts would force elk to cross roads on the surface, again endangering human vehicle traffic and the elk themselves. This highlights the need for adaptive management, to ensure that changing conditions do not curtail previous wildlife corridor efforts.

Wildlife culvert

Wildlife overpass

Conclusion

This project demonstrated the benefits of creating wildlife corridors for both humans and species that have had their natural habitats reduced. With the use of wildlife corridors, animals are able to roam closer to their natural ranges in pursuit of food and breeding needs. Additionally wildlife corridors that use culverts or overpasses help wildlife avoid human highways, which of course can have damaging consequences.

Unfortunately I also learned that in Arizona wildlife corridors have become victims of budget cutbacks (http://azstarnet.com/news/science/environment/article_7012945a-07d2-5ff6-909a-8f37d1738468.html). In addition to stopping ongoing studies for new wildlife corridors, longtime consultants on the placement of wildlife corridors have also been let go. This will make future wildlife corridors an uphill battle to be created and maintained.

While I had heard about wildlife corridors being needed for endangered species, I didn't realize how vital these corridors are even for our local wildlife. I can certainly appreciate the need for wildlife to not be limited in their territory by artificial barriers, as well as helping ensure motorist safety. I hope that Arizona will be able to find the funding it needs to keep wildlife corridors alive, as the long-term benefits should outweigh short-term cash flow issues.

Wildlife Corridor Poster