Environmental Review Toolkit
Water, Wetlands, and Wildlife

small pic of map of AZ  showing habitats and linkages
Arizona's Habitats and Links. (AZDOT)
Bighorn Sheep on hillside
Collars enable satellite tracking of Bighorn Sheep movement. (AZDOT)

Arizona Department of Transportation

Arizona Wildlife Linkages Initiative

When motivated people with diverse backgrounds come together to resolve issues, the results can be long-lasting and far-reaching. The Arizona Wildlife Linkages Workgroup (AWLW), for example, is a multi-organizational public-private partnership which sponsored a series of groundbreaking workshops followed by several years' refinement of the collected information. The group's efforts have led to a technically defensible system for integrating wildlife protection into transportation planning--a strategy that promises to benefit all users of Arizona state highways.

The Issues: Arizona--home to nearly 900 vertebrate wildlife species--ranks third in the nation for biodiversity. The phenomenal growth of Arizona's population, economy, and infrastructure poses new challenges for maintaining natural ecosystems and wildlife populations which make up an important part of the state's wealth. For example, roads, urbanization, canals, railways, and power lines not only destroy habitat but create barriers that isolate wildlife populations and disrupt migration and other ecological functions. Removing these barriers one at a time is expensive and inefficient. So AWLW is using a landscape approach to successfully maintain and restore habitat linkages and conserve the natural ecosystems on which Arizona's residents and visitors rely and from which they benefit.

The Process: AWLW partners include the Arizona Department of Transportation (ADOT), Arizona Game and Fish (AGFD), the Bureau of Land Management, FHWA, Northern Arizona University, Sky Island Alliance, the USDA Forest Service, the U.S. Fish and Wildlife Service, and the Wildlands Project. Through this partnership and commitment to reducing habitat fragmentation, a series of statewide "Missing Linkages" workshops were conducted to enable buy-in and to gather information from local experts about large blocks of protected habitat, potential linkage zones, and threats to such zones.

The workshops and subsequent brainstorming sessions have paid off. For example, AWLW used the experts' information to create the Arizona Wildlife Linkages Assessment--a technical tool for engineers and transportation planners in consulting firms, non-profit organizations, and federal, state, and local agencies. The Assessment defines existing linkage conditions, records biotic communities, lists species that depend on particular linkages, identifies land ownership within these linkages, and details known and anticipated threats. A geographic information system map was also created to graphically display areas of concern. So far, AWLW has identified more than 150 potential linkage zones throughout the state, and it is anticipated that this number will double in the future.

The workshops and follow-up meetings also led to a cooperative research-and-construction project on northwestern Arizona's State Route 68 to test different forms of crossings for a unique population of desert bighorn sheep. When the highway was widened in 2002, ADOT used two geometric designs for sheep crossings. Using pooled research monies, AGFD monitored the sheep's use of both crossings and discovered a distinct preference for one over the other. Other research has recently been completed on U.S. Highway 93 through the Lake Mead National Recreation Area, where there is a large resident population of desert bighorn sheep. Specially designed crossings, along with fencing, will allow the sheep to safely cross the highway. Future research studies in this area and elsewhere will benefit all AWLW partners.

Piecemeal, independent solutions to the issues of habitat fragmentation are a thing of the past in Arizona. A cohesive, systematic approach involving many partners is the wave of the future--and a fact of the present.

For more information, contact Steve Thomas, steve.thomas@fhwa.dot.gov

HEP Home Planning Environment Real Estate

Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000