Monitoring Wildlife Mortality in Railways: General
Approaches
Railway mortality can negatively affect some species. It is, therefore, crucial to
accurately monitor casualties that will reveal areas of high killing rates (i.e., hotspots). This will allow a correct assessment of environmental factors influencing
higher mortality rates and the application of proper mitigation measures (Gunson
et al. 2011). However, most of our understanding on railway impacts comes from a
small number of studies in North America and Europe on a few species, primarily
large mammals, such as moose and bears (e.g., Dorsey et al. 2015).
Why Is Monitoring Important?
Ideally, before implementing any linear infrastructure, it is advisable to assess its
possible impacts (e.g., vegetation removal, soil movement, noise, light pollution,
etc.) in adjacent areas. In addition, species richness and abundance must be
recorded to establish a baseline to identify possible conservation concerns (e.g.,
extinction risk of rarer species) (van der Grift et al. 2013). This is especially
relevant when the infrastructure is to be placed across a natural protected area,
encompassing several ecosystems (Dorsey et al. 2015). Then, during and after
construction, a monitoring plan aiming to measure the impact of collisions, electrocution, rail entrapment, use of culverts, and other aspects of the railway, is
crucial for forecasting and understanding the behavioral responses of animals living
in the vicinity (Iuell et al. 2003; van der Grift et al. 2013). Therefore, based on the
results obtained, we endeavor to set up the best mitigation solutions for each
situation.
So far, most research and monitoring studies have assessed the use and effectiveness of wildlife crossing structures (Hunt et al. 1987; Rodríguez et al. 1996). To
counteract this, we focus on the monitoring of wildlife mortality, as it is the most
visible direct impact of linear infrastructures (van der Grift et al. 2013). Some
impacts of railways differ from those of roads for example, the casualties from
electrocution, rail entrapment and wire strikes (Dorsey et al. 2015), which suggests
the need for specific monitoring programs.
Designing a Wildlife Mortality Monitoring Plan for Railways
Monitoring is limited by practical considerations of cost and feasibility, so a survey
of all species is unrealistic (Rytwinski et al. 2015; van der Grift et al. 2013). In fact,
costs are one of the main reasons that the state of the habitats and species crossed by
a railway are often not assessed. However, regardless of the cost considerations, the
24
F. Carvalho et al.
Approaches
Railway mortality can negatively affect some species. It is, therefore, crucial to
accurately monitor casualties that will reveal areas of high killing rates (i.e., hotspots). This will allow a correct assessment of environmental factors influencing
higher mortality rates and the application of proper mitigation measures (Gunson
et al. 2011). However, most of our understanding on railway impacts comes from a
small number of studies in North America and Europe on a few species, primarily
large mammals, such as moose and bears (e.g., Dorsey et al. 2015).
Why Is Monitoring Important?
Ideally, before implementing any linear infrastructure, it is advisable to assess its
possible impacts (e.g., vegetation removal, soil movement, noise, light pollution,
etc.) in adjacent areas. In addition, species richness and abundance must be
recorded to establish a baseline to identify possible conservation concerns (e.g.,
extinction risk of rarer species) (van der Grift et al. 2013). This is especially
relevant when the infrastructure is to be placed across a natural protected area,
encompassing several ecosystems (Dorsey et al. 2015). Then, during and after
construction, a monitoring plan aiming to measure the impact of collisions, electrocution, rail entrapment, use of culverts, and other aspects of the railway, is
crucial for forecasting and understanding the behavioral responses of animals living
in the vicinity (Iuell et al. 2003; van der Grift et al. 2013). Therefore, based on the
results obtained, we endeavor to set up the best mitigation solutions for each
situation.
So far, most research and monitoring studies have assessed the use and effectiveness of wildlife crossing structures (Hunt et al. 1987; Rodríguez et al. 1996). To
counteract this, we focus on the monitoring of wildlife mortality, as it is the most
visible direct impact of linear infrastructures (van der Grift et al. 2013). Some
impacts of railways differ from those of roads for example, the casualties from
electrocution, rail entrapment and wire strikes (Dorsey et al. 2015), which suggests
the need for specific monitoring programs.
Designing a Wildlife Mortality Monitoring Plan for Railways
Monitoring is limited by practical considerations of cost and feasibility, so a survey
of all species is unrealistic (Rytwinski et al. 2015; van der Grift et al. 2013). In fact,
costs are one of the main reasons that the state of the habitats and species crossed by
a railway are often not assessed. However, regardless of the cost considerations, the
24
F. Carvalho et al.