Road Ecology Center

Loss of access to critical habitats is a key wildlife concern, particularly for species listed for protection by state and federal agencies. Rail corridors pose unique design challenges by virtue of the need to avoid abrupt changes in track curves and grade in the right of way (ROW). Spotted turtles (Clemmys guttata) are particularly vulnerable to habitat fragmentation due to their limited mobility and dependence on a diversity of specific foraging, nesting, and aestivation habitats. Spotted turtles also display an apparent reluctance to enter or cross through narrow and confined culverts typically found under road and rail line ROWs. In association with the Greenbush Line Commuter Railroad Restoration Project, the Massachusetts Bay Transportation Authority initiated a demonstration project in spring of 2003 to determine the effectiveness of a proposed railroad crossing structure in an urbanized landscape. Three identical, open-air prototypes were positioned in the ROW of a former railroad bed between adjacent wetlands known to support spotted turtles. Each structure was linked with temporary funneling barriers along the track edges. Structure placement was in accordance with microhabitat survey assessments, radio telemetry data, and direct movement observations. To evaluate the effectiveness of the structures, remote photographic stations were established at each crossing, and radio telemetry was used to track turtle movements. Monitoring was conducted from April 2, 2003, until July 8, 2003. Study results demonstrated spotted turtle crossing patterns and frequency through the ROW during the monitoring period similar to that prior to barrier development. Crossings also were shown to be utilized by 17 other wildlife species, including reptiles, amphibians, birds, and mammals. The demonstration project concluded that location and design of the crossing structures provided an effective means of maintaining habitat connectivity for a variety of wildlife species, as well as spotted turtles. As part of the Conservation and Management Plan developed for the Greenbush Line Project, which is now under construction, 45 wildlife crossing structures are proposed at key locations along the ROW. A post-construction monitoring plan will be conducted to evaluate the use of these structures by wildlife species.