Introduction

Sacramento County has proposed to replace the Franklin Boulevard Bridge. This wooden trestle bridge is home to one of the largest maternal bat colonies in Northern California. During the early planning phase of this project, it became apparent that unless mitigation steps are taken, demolition and construction could irreparably harm the colony, a unique and highly beneficial ecological and agricultural resource. It was determined that an aggressive pro-active bat protection plan would be needed prior to the demolition of the existing bridge. This report outlines the history of the project and the steps that were taken to protect the bat colony by providing substitute habitat during the construction of the new bat-friendly bridge.

The authors anticipate a three-part report. This report should be considered Part 1 of the documented bat protection efforts at the Franklin Boulevard Bridge. Part 1 consists of provision of temporary bat habitat away from the bridge and trial efforts to exclude the existing population from using the bridge as a material roosting site.

Part 2 will be added after the activities of the 2000/2001 season can be documented. These activities will include the final bat exclusion efforts on the existing bridge, demolition of the existing bridge, and monitoring of the colony during this period.

Part 3 will discuss the ultimate success of this program after the bridge replacement is completed. We will also document the return of the colony and how the bats use the new bridge.

We hope that our documentation of the activities at the Franklin Bridge will be of help to other agencies considering projects similar to the bridge replacement project in Sacramento County. We have found that providing bat habitat in a new bridge is feasible and cost effective, but that excluding the bats from the old bridge during the construction phase of the project can be challenging. Since there is little information available regarding the means to achieve this type of short-term mitigation, we have tried to document our activities in detail so that others can learn from our mistakes and emulate our successes. We feel that our main success has been learning about the benefits of bats in our environment and educating the greater community in this regard. Sacramento County is committed to the proactive protection of this amazing animal and will continue to seek ways to nurture its presence in our community.

The goals of the County of Sacramento Franklin Boulevard Bat Protection Program are to:

• Protect the existing bat colony;
• Maintain the colony in the general area;
• Provide short-term and long-term habitat to maintain populations at existing or greater levels;
• Collect information for evaluating effectiveness of short-term and long-term habitat;
• Establish communication with experts and regulatory agencies to develop an approach for successful habitat replacement that can be applied elsewhere; and
• Contribute the information from this program to citizens and organizations involved in programs aimed at bat conservation.