Road Ecology Center

With the release of the Arizona’s Wildlife Linkages Assessment, November 2006, the Arizona Wildlife Linkages Workgroup is working to integrate and incorporate wildlife concerns and habitat connectivity needs into the forefront of transportation and regional planning processes to address habitat fragmentation due to highways and other human development.

Arizona, ranking third nationally for biodiversity, is home to nearly 900 vertebrate wildlife species. The phenomenal growth of Arizona’s human population, economy and infrastructure present challenges to the maintenance of natural ecosystems and wildlife populations that constitute an important part of the State’s wealth. In particular, roads, urbanization, canals, railways, energy corridors and activities of illegal migrants and border security operations not only destroy habitat, but create barriers that isolate wildlife populations and disrupt ecological functions such as gene flow, predator-prey interactions, and migration. Addressing each of these potential barriers one-at-a-time is expensive and inefficient. In each landscape, we must address all these factors concurrently to successfully maintain or restore linkages between habitats and conserve the wildlife and natural ecosystems that Arizona’s residents and visitors rely on and benefit from.

Road kill has become a common sight along many Arizona roadways - conspicuous evidence of habitat fragmentation. The results of these often-fatal encounters have far-reaching effects. Wildlife-vehicle collisions cause human deaths and injuries, millions of dollars in property damage, loss of game and non-game animals, and sometimes expose the State to liability. Working together, federal, state, county and private stakeholders can minimize these social costs while enhancing opportunities for movement of wildlife between Arizona’s habitat areas.

The Arizona Wildlife Linkages Workgroup (AWLW) is a collaborative effort formed by the Arizona Department of Transportation, Arizona Game and Fish Department, Bureau of Land Management, Federal Highway Administration, Northern Arizona University, Sky Island Alliance, USDA Forest Service, U.S. Fish and Wildlife Service and the Wildlands Project to address habitat fragmentation through a cohesive, systematic approach. Through this partnership and commitment, a series of successful statewide workshops were conducted in order to facilitate “buy-in” to the process and gather information from local experts to identify: 1) large blocks of protected habitat; 2) wildlife movement corridors (potential linkage zones) between as well as through them; and 3) factors threatening to disrupt such linkage zones.

In November 2006, after several years of refinement, the AWLW has produced the Arizona’s Wildlife Linkages Assessment along with a map to graphically display the areas of concern. AWLW expanded upon the original workshop information and has worked to further define existing conditions, record biotic communities, list species that depend on particular linkages, identify land ownership within those linkages, and detail anticipated in addition to known threats. Currently, more than 150 potential linkage zones have been identified throughout Arizona.

The potential linkage zones were prioritized based on biological importance and the existing, as well as anticipated, threats and opportunities for preservation and/or restoration. This prioritization was used to identify several key linkages for additional analysis and development of site-specific linkage designs. In most cases, only a fraction of the land in a potential linkage zone will need to be conserved. To date, eight have been completed. Each linkage design includes a map of critical land to be conserved, recommendations for structures to facilitate wildlife crossing of roads, railroads, canals, and other human caused barriers, and management recommendations for multiple-use landscapes.

Even prior to official release, statewide planners have been utilizing this Assessment for projects including bond initiative development, regional growth concerns and transportation project development. The Assessment provides a starting point for detailed consultation and coordination by providing a common reference point. With early consideration, the opportunity is created to resolve environmental issues pertaining to wildlife connectivity and wildlife-vehicle collisions while reducing project development costs. Furthermore, the formation of the AWLW has facilitated discussions and partnerships to help ensure a unified approach to wildlife linkage preservation and management while rein-forcing the commitment and efficiency of wildlife connectivity measures undertaken by all stakeholders. Recognized as an important component, this Assessment is considered in the Governor’s Growth and Infrastructure Initiative. Overall, utilization of this Assessment is a strategy that promises to benefit all of Arizona.

This was only the first step in a continuing process of defining and elevating the awareness of critical habitat connectivity areas. Substantial work has begun on identifying and mapping additional linkage zones within habitat blocks. It is anticipated that this will double the current number of linkage zones. As new linkage zones are added, road construction programs are updated and development in the State progresses, this evaluation and resulting prioritization will be revised and updates issued. Also, linkage designs will be developed for each potential linkage zone. Another eight linkage zones have recently received funding for linkage design analysis and the work is underway. A website and workshops are being developed to promote the utility of the Assessment.