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Joseph A. Burns CWB
National Threatened and Endgangered Species Program Leader
Watershed, Fish, Wildlife, Air, Rare Plants
1400 Independance Ave SW - MS1121
Washington, D.C. 20250-1121
(202) 205-0919


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Case Histories

Learning from Experiences

Case histories are great ways to learn from others' experiences. In this section you will find examples of how real people tackled challenging projects. Generally speaking, the most successful projects had three commonalities:

  1. Early engagement by the resource agencies, many of whom contacted experts to assist local units.
  2. Strong support from line officers for resource management and protection.
  3. Continued engagement by resource specialists throughout planning and construction.

Unlike the first version of the Wildlife Crossings Toolkit, we are not attempting, nor would we be able, to provide a complete catalog of projects with wildlife issues or applied mitigation measures. Where only a hundred or so projects in the world could be listed in 2000 in the original WCT, now there are hundreds of examples in the United States alone.

Further, there are now several good works that have case histories. Notable is the newest book called Safe Passages, which has an excellent treatment of the flagship projects in North America now.

Many of the following case histories are not yet completed projects. Some are in the early planning phase, and others are finalizing several years of monitoring. Each of these phases has a different set of lessons to share. Case histories can be management actions unrelated to highway improvements, such as roadside vegetation management.

Case Histories on Public Lands

The Wildlife Crossings Toolkit is targeted towards natural resource agency specialists, especially wildlife professionals. The following case histories are illustrative of the types of challenges faced on public lands. Often these are dramatically different than highway projects in urban areas. One obvious difference is that there is excellent wildlife habitat on public lands, and therefore the impacts of highways are more obvious in terms of roadkill. Less obvious are the effects of loss of habitat connectivity.


Case Histories on Other Lands

These case histories are not necessarily on public lands, but they have lessons especially noteworthy or useful to natural resource managers.


Retrofitting Case Histories

These case histories illlustrate the concepts outlined in the decision support tools in the section on Retrofitting in the Resources section of the Wildlife Crossings Toolkit.

What is a 'retrofit'? As used here on the Wildlife Crossings Toolkit, a retrofit is a modification to an existing structure or situation that enables it to be better used by terrestrial wildlife, rather than new construction to replace an existing structure. Examples of retrofits include adding fencing to an existing bridge to funnel animals under the bridge or modifying a culvert's bottom surface to improve the substrate to be more salamander-friendly.


**Use the contact information on the left side of the page to request more information on these case histories.

Page Last Modified: July 21, 2015

Additional Information

Aquatic biodiversity in a bucket taken from a small stream on the Cherokee NFIn the United States, a recent study estimated there are more than one million collisions between vehicles and large animals annually.

This 25-minute safety training program will help you reduce your probability of having large animal-vehicle collisions, especially with deer.

Several other sources now provide case history information of value to public land managers.

The most thorough and current treatment of the 'flagship' projects such as Montana US 93, Arizona SR 260, and Washington Interstate 90 projects are found in the new book, Safe Passages: Highways, Wildlife and Habitat Connectivity, edited by JP Beckmann, AP Clevenger, MP Huijser, and JA Hilty (Island Press, 2010).

Chock full of excellent detail and images, the Best Practices Manual Wildlife Vehicle Collision Reduction Study, Report to Congress (2008) is available online.