Abstracts: Wildlife Crossing Structures: Planning, Placement, Monitoring
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Design, Installation, and Monitoring of Safe Crossing Points for Bats on a New Highway Scheme in Wales
Dr. Stephanie Wray (Phone: 01453 731231, Email: firstname.lastname@example.org), Paola Reason, David Wells, Warren Cresswell and Hannah Walker, Cresswell Associates, The Mill, Brimscombe Port, Stroud, Gloucestershire GL5 2QG United Kingdom
The greater horseshoe bat (Rhinolophus Ferrumequinum) is strictly protected under European Union (EU) and United Kingdom (UK) legislation. This serves to ensure that the species (as well as its roosting sites and feeding habitat) receives strict protection and that appropriate monitoring of populations will be undertaken.
The Milton-Carew-Sageston area of West Wales (UK) has been shown to be utilized by much of the Welsh population of greater horseshoe bats. Potentially, therefore, anything which significantly affects this area could have an important impact upon the survival of this population.
A proposed road scheme, the A477 Sageston to Redberth Bypass, was to pass through a mosaic of pasture, hedgerows, marshy stream courses, and small woodlands, which constitutes near optimal foraging habitat and dispersal routes for bats. Greater horseshoe bats had been shown to cross the existing road in several locations, and there were known to be nine principal greater horseshoe bat roosts within 2.5 km of the study area.
In order to reduce the likelihood of the bats being killed on the new road, it was necessary to discourage the bats from foraging along the road verge, while simultaneously providing safe and attractive crossing points, at locations where the bats were already known to cross the route of the proposed road. This involved: (i) the maintenance of attractive linear features (lines of trees, hedgerows, etc.) perpendicular to the route to lure the bats away from the road; (ii) a relatively wide verge of poor quality habitat (e.g., amenity grassland, hard standing, etc.) directly adjacent to the carriageway (and for some distance along it) to discourage the bats from foraging along the road; (iii) safe crossing points at culverts underneath the road on the alignment of existing flight lines; and (iv) the omission or alteration of street lighting at crossing points to be retained so that these areas remain in relative darkness.
The exact location of the tunnels, the planting leading to them, and the engineering design of the tunnel approaches were developed by an integrated team of ecologists and engineers.
The measures were installed in 2002, and the road opened to traffic in 2003. The success of the mitigation measures have been monitored through bat activity surveys in 2003 and 2004, and the tunnels are proving to be extremely effective in allowing bats to cross the road safely. No records of bat/vehicle collisions have been recorded.
Information is also provided on other schemes in Wales which have involved the provision of safe crossing points and mitigation for horseshoe bats.
Ecological Impacts of SR 200 on the Ross Prairie Ecosystem
Daniel J. Smith (Phone: 352-213-3833, Email: email@example.com), Research Associate, Department of Biology, University of Central Florida, Orlando, Florida 32801
Ross Prairie is a 6,500-ha conservation area in SW Marion County, Florida. It serves as an important regional habitat node connecting the Ocala National Forest to the Withlacoochee and Goethe State Forests. SR 200 is a major two-lane state highway that bisects the reserve. Rapid growth and development have recently necessitated the need to widen the road to four lanes. A comprehensive approach that employed several methods was used to determine the current and potential impacts of SR 200. These methods included road-kill and track surveys, mark-recapture and telemetry studies, and GIS analysis. Each method was used to evaluate road impacts on different taxa. The study was conducted from May 2002 to December 2004. Results of the road-kill surveys included 759 individuals from 57 identifiable species. The majority were anurans followed by meso-mammals. Locations of significant numbers or rare species of road-kills by taxa were identified. A total of 537 sets of whitetail deer, 481 sets of carnivore, and 474 sets of snake tracks were recorded. Hotspots were identified for snake, white-tail deer, and carnivore tracks. A total of 1,777 herpetiles were captured in right-of-way drift fence traps. Southern leopard frogs and Florida gopher frogs were most abundant. Individuals of several species of snakes, frogs, and lizards were recorded crossing the road in the two sandhill crossing sections, and moving to/from the Ross Prairie wetland basin. Of 342 small mammals captured, one cotton mouse was recorded crossing the road; only six small mammals were found as road-kills. The road likely is a significant barrier to small mammal movement. Average home range of 18 gopher tortoises monitored adjacent to the road was 3.14 ha. Only three attempted crossings of SR 200 were recorded, two were successful, and one resulted in death. For gopher tortoise, the road is a semi-permeable barrier. Home range of the 13 eastern indigo snakes monitored averaged 127.6 ha. No road crossings were recorded; they seemed to use the road as a home range boundary. Because of road-kills, there is documented evidence that road crossings are attempted. Only 5 bobcats, 2 coyotes, and 1 gray fox were captured and used in the carnivore telemetry study. Yet observations, track, and scat evidence suggest that a significantly higher number of these animals were present in the Ross Prairie area. Average home range size was 13.67 km2 for bobcats. Most radio-collared felids avoided SR 200 or used the road as a home range boundary, whereas the radio-collared canids commonly crossed major roads. To improve habitat connectivity and eliminate road mortality we recommended installing four box culverts in the upland sandhill areas, bridges at each wetland/upland ecotone, and a series of five culverts within the wetland basin adjoined by a herpetile exclusion wall. Between all these structures we suggested 2-m barrier fencing with herpetile-excluding mesh at the base of the fence.
How Far Into a Forest Does the Effect of a Road Extend? Defining Road Edge Effect in Eucalypt Forests of South-Eastern Australia
Zoe Pocock (Phone: 03 54397521, Email: firstname.lastname@example.org) and Ruth E. Lawrence, School of Outdoor Education and Environment, La Trobe University, Bendigo, Australia
The concept of the road-effect zone has been developed and researched predominantly in the Northern Hemisphere. This study measures the extent of road impacts into a temperate eucalypt forest ecosystem in southeastern Australia. The Epsom-Barnadown Road is a two-lane arterial road connecting regional centres in northern Victoria to the City of Greater Bendigo. Passing through the Bendigo Regional Park, the Epsom-Barnadown Road carries more than 1,600 vehicles per day. Transects of 1 km in length cited perpendicular to the road were established to measure road impacts on the flora and fauna of box-ironbark forest. Exotic vegetation was found to extend about 50 m from the road. Traffic noise and light penetration varied according to topography and vegetation cover, but averaged of 350 m and 380 m, respectively, from the road. Mammal surveys indicated there was an increase in species richness once traffic noise reached ambient levels (40 dB) and traffic light penetration ceased. Bird surveys resulted in the identification of four species (9%) that only occurred within 150 m of the road (edge species) and 21 species (58%) that only occurred at distances of 150 m or more from the Epsom-Barnadown Road (interior species). A core habitat area for bird species was identified at about 900 m from the road. It was found that the average width of forest in the Bendigo Regional Park impacted by the Epsom-Barnadown Road was 1800 m, which translates to an area of 1.8 km2 per kilometre of road.
How Many Days to Monitor a Wildlife Passage? Species Detection Patterns and the Estimation of the Vertebrate Fauna Using Crossing Structures at a Motorway
J.E. Malo (Phone: +34 91 497 8012, Email: email@example.com); I. Hervás; J. Herranz; C. Mata. and F. Suárez, Departamento de Ecología, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
The barrier effect imposed by roads and railways on vertebrate populations has aroused both scientific and social concern and has led to the construction of crossing structures for such fauna in new infrastructures. Good practice demands that investment in such mitigation measures should be followed by systematic monitoring of their effectiveness, in order to improve the design of further works. These monitoring schemes need standardized protocols in order to deliver scientifically sound results at an affordable cost. In this context, the present contribution analyzes the suitability of monitoring schemes aimed at determining which vertebrate species use crossing structures in relation to the number of days spent monitoring each crossing structure. The analysis considers data on vertebrates using 22 structures crossing a motorway in northwest Spain, which were monitored for 15-26 consecutive days. Species accumulation curves were fitted by non-linear estimation procedures to the species accumulation pattern detected at each crossing structure in order to estimate the asymptotic number of species using each one of them. Modelling was carried out using 11 functions applied in ecological studies to analyze species accumulation curves in relation to sampling intensity. The results show that species accumulation curves for crossing structures have a rapid increase phase followed by a long tail of slow accumulation. Thus, 25 or more monitoring days may be needed to detect over 80 percent of the species using a crossing structure, but 60 percent of them are detected by day 10, and 70 percent, by day 16. The statistical fit obtained for different function types allows the Clench model to be recommended for evaluating the results obtained in monitoring programs intended to determine the number of species using each crossing structure. This model yielded the highest mean explanatory power (mean r2=0.905) using only two parameters; it provided neither a systematic overestimate nor an underestimate of richness, and offered a low degree of uncertainty (2.3% non-significant parameters). In short, 10 to 15 days of monitoring may be enough to provide a basic knowledge of the animal species using crossing structures at a particular time, although the monitoring period could be somewhat shorter or longer according to the requirements of particular cases.
Railroad Crossing Structures for Spotted Turtles: Massachusetts Bay Transportation Authority–Greenbush Rail Line Wildlife Crossing Demonstration Project
Steven K. Pelletier (Phone: 207-729-1199, Email: firstname.lastname@example.org), Lars Carlson, Daniel Nein, and Robert D. Roy, Woodlot Alternatives, Inc., 30 Park Drive, Topsham, Maine
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.
Spotted Turtle Use of a Culvert Under Relocated Route 44 in Carver, Massachusetts
Delia R. J. Kaye (Phone: 617.607.2945, Email: email@example.com), Senior Environmental Specialist, Vanasse Hangen Brustlin, Inc. Box 9151, 101 Walnut Street, Watertown, Massachusetts 02471; Kevin M. Walsh, Massachusetts Highway Department; Eric L. Rulison, Hofstra University; and Christopher C. Ross, Massachusetts Department of Environmental Protection
A new highway alignment for relocated Route 44 in Carver, Massachusetts, resulted in the direct alteration of 2.5 acres and indirect alteration of 3.9 acres of habitat for three statelisted turtle species: the wood turtle (Clemmys insculpta), spotted turtle (Clemmys guttata), and eastern box turtle (Terrapene c. carolina).
As part of the mitigation requirements for impacts to rare species habitat, the Massachusetts Highway Department (MassHighway) conducted a two-year preconstruction study to determine the habitat preferences and seasonal movements of the statelisted species. The study determined that no wood turtles were present in the study area, that there was a large but declining population of box turtles, and that two highly used spotted turtle habitats would be bisected by the proposed highway entrance ramp. An intermittent stream channel proposed to be piped under the new entrance ramp was identified as a primary travel corridor between the two habitats.
Based on the findings of the preconstruction study, MassHighway identified a simple solution to allow the stream channel to continue to provide a migratory corridor for spotted turtles. To achieve this goal, MassHighway increased the proposed culvert size from a 24inch pipe to a 6foot by 6foot box culvert. In the spring and summer of 2004, post-construction monitoring was conducted to determine the effectiveness of the culvert as a spotted turtle crossing structure. Nine turtles were fitted with radio transmitters and thread bobbins and followed three times per week in the spring and early summer, and once per week in the late summer to determine culvert effectiveness. Direct evidence (thread trails, visual observation) was documented for seven turtles, and indirect evidence (radio telemetry points on both sides of the culvert, visual observation) was documented for 13 turtles, confirming the use of the culvert as a crossing structure. A future study is recommended to document potential effects of traffic and noise on the spotted turtle population, continued use of the culvert, and potential changes to rare species habitat from the highway construction.
Use of Highway Underpasses by Large Mammals and Other Wildlife in Virginia and Factors Influencing Their Effectiveness
Bridget M. Donaldson (Phone: 434-293-1922, Email: firstname.lastname@example.org), Virginia Transportation Research Council, 530 Edgemont Road, Charlottesville, VA 22903
Remote cameras installed at seven underpass sites in Virginia have recorded more than 2,700 wildlife photographs and documented 1,107 white-tailed deer crossings in the most heavily used structures. Underpasses with a minimum height of 12 ft were successful at facilitating deer passage. Such structures were also heavily used by a variety of wildlife species, including coyote, red fox, raccoon, groundhog, and opossum. Structures with drainages that mimic natural waterways can encourage use by a diversity of terrestrial, semi-aquatic, and aquatic species.
This report provides guidance in choosing cost-effective underpass design and location features that are necessary to consider to increase motorist safety and habitat connectivity. The findings also demonstrate that if only a minimal number of deer-vehicle collisions is prevented by an effective underpass, the savings in property damage alone can outweigh the construction costs of the structure.
Wildlife Crossings in North America: The State of the Science and Practice
Dr. P. C. Cramer (Phone: 435-797-1289, Email: email@example.com), Research Associate, and Dr. John A. Bissonette, Research Scientist, USGS Utah Coop Unit, Utah State University, Natural Resources Bldg., Utah State University, Logan, UT 84322-5290
In this paper we present results from a telephone survey as part of a National Cooperative Highway Research Program (NCHRP) project, Evaluation of the Use and Effectiveness of Wildlife Crossings (NCHRP 25-27). Specifically, we present a summary of North American efforts to mitigate road effects for wildlife. We stress the need to provide multiple wildlife passages along transportation corridors to begin to accommodate the movement of the full complement of species in an area. We surveyed over 250 transportation professionals in the United States and Canada by telephone to learn more about efforts to make roads more permeable for wildlife. We asked questions about both the practice and science associated with road ecology. Participants employed by agencies, private organizations, and academic institutions answered questions concerning wildlife crossings, planning for wildlife and ecosystems, animal-vehicle collision information, and past, current, and future research activities related to roads and wildlife. As of September 2005, we found that there were at least 460 terrestrial and 300 aquatic crossings in North America. Trends in practice over time since wildlife passages began to be installed in the 1970s appear to show an increased number of target species in mitigation projects, increased numbers of endangered species used as target species for mitigation, increasing involvement of municipal and state agencies, an increase in the number of passages and accompanying structures constructed, and a continent-wide trend of neglect of maintenance of these passages. The trends in the science revealed a tendency for a broadening of the scope of research in terms of the number of species considered, an increase in the length of time monitoring projects were conducted, and an increase in the number of participants in scientific monitoring of mitigation projects and in general road ecology research. There are several projects in North America where multiple crossings have been or will be installed to accommodate a large suite of species and their movement needs. These include Alberta's Trans Canada Highway mitigation efforts, Montana's U.S. Highway 93 mitigation projects, Arizona's projects along U.S. 93 and on State Route 260, Florida's I-75 Alligator Alley project, and Vermont's future Route 78 and US 7-SR 9 projects. These projects may be models for how road construction activities can increase the permeability of the roaded landscape. We also present recommendations to assist in the research, design, placement, monitoring, and maintenance of crossings. We summarize the state of the practice and science of road ecology with respect to wildlife with suggestions to increase permeability of transportation corridors, and to increase communication and cooperation among those who would be involved in the mitigation of roads and other travel corridors.
Wildlife Tunnels and Fauna Bridges in Poland: Past, Present and Future, 1997-2013
Jadwiga Brodziewska (Phone: 0048 508303946, Email: firstname.lastname@example.org), Towarzystwo Badan i Ochrony Przyrody (The Wildlife Research and Conservation Society), ul Dwernickiego 8A/31, 16-400 Suwalki, Poland
In Poland the road and rail network crosses many sensitive areas, such as national parks, landscape parks, wildlife reserves, landscape protection areas and Natura 2000 sites, i.e., the protected area system of the European Union, because of road density, high landscape diversity, and its mosaic pattern. As a consequence of Poland joining the European Union in 2004, many changes have happened and are still happening all over the country, especially in building new roads and railway lines. The harmonization of the Polish legal system with the EU directives required the improvement of environmental legislation making the monitoring before and after the building of such constructions necessary together with the preparation of environmental assessment studies. The animal migration problem has become one of the most important barriers in the decision-making process on where to build new roads and improve others. According to the previous plans, most of the roads that should have become expressways or highways of national or international importance also bring higher traffic and driving speed in those areas. As a consequence, the risk of collisions became higher and many motorists died in fatal accidents. On average, on the 160-km A2 highway running from Nowy Tomysl to Konin, 40 accidents with mammals were recorded in one month in 2003. The consciousness of the society grew enormously following these events, and it also urged the appropriate governmental institutions, as well as private companies, investors, and non-governmental organizations, to study animals along the roads all over the country, with special attention to their movement. As a first step toward solving this problem, the identification of animal migration routes became an important task. Besides large species that can cause the death of the driver when colliding with a car (such as elk, deer, wild boar), several smaller animals (such as fox, badger, amphibians or reptiles) with vulnerable populations in the surveyed area were also studied, and the building of passages and bridges for wildlife has become not only an obligation but also a necessity both at the constructor as well as at the social level. Since 1997 more than ten overpasses and one underpass were built for large mammals (elk, deer, wolf, wild boar) in Poland. They are located along the E65 international road, Katowice - Kraków and the Przylesie - Nowogowczyce sections of the A4 highway, Poznan - Nowy Tomysl and Nowy Tomysl - Konin sections of the A2 highway, Stryszek- Biale Blota section of the no. 10. national road, and Komorniki - Steszewo section of the no. 5. national road. The decision about the exact location of the game bridges and the game passage was made after detailed interviews with national park officials and foresters, in addition to the results of field work. The monitoring of the effectiveness of these constructions revealed a lot of mistakes and often proved no use of the mitigation measures by the target animals. The main reasons for non-functioning were too-small dimensions, especially width in all of game bridges; lack of screens separating the animals from noise; vibration, light and visual disturbances, no or not enough vegetation on the bridges; lack of guiding structures leading the animals to the passages; and lack of fences along the road. As a consequence of such results, mitigation measures were improved and maintained better. For small mammals, amphibians, and reptiles, nine underpasses were built in 2004 along the Budzisko - Augustów section of the international road called Via Baltica, Jeleniów section of the local road next to the E67 international road, and Chabówka - Rdzawka section of the E 47 expressway. The decision about where to put tunnels was made on the basis of field research (day and night transects, the sound monitoring of amphibians, and amphibian breeding sides investigations) made by national park staff, private companies, and volunteers. The follow-up monitoring of these structures showed that the effectiveness of the tunnels with guiding structures is nearly 100 percent for amphibians and reptiles and 85 percent for small mammals. In the following nine years (2005-2013) several more wildlife passages will be built on Polish roads along the Lódz - Czestochowa section of the A1 highway, Przylesie - Prady section of the A4 highway, Rosnówek section of the no. 5. national road, Zywiec - Zwardon section of the S69 international road, Wyszków - Skuszew section of the no. 8. national road, and Poznan - Kórnik section of the no. 11. national road. From among these constructions the most important passages will be along the Zywiec – Zwardon section of the S69 international road, as they will be aimed to protect wildlife of international importance (bears, lynx, and wolves).