Introduction
Many animals range widely across landscapes in the quest to meet their daily,
seasonal and annual biological needs of food, water, shelter and mates (Caughley
and Sinclair 1994). Habitat connectivity within a landscape helps dispersal and
re-colonization, thus maintaining regional metapopulations and minimizing risks of
inbreeding within populations (Newmark 1987; Wilcove et al. 1998). Historically,
the spread of agriculture probably contributed the most to loss and fragmentation of
their natural habitat. In an increasingly industrialized world, however, transport
networks (railways, roads, and waterways) or so-called “linear infrastructures,”
restrict the movement of wildlife populations by fragmenting their habitat,
increasing edge effects, constricting ecological corridors, blocking animal movement, and increasing the risk of mortality due to direct collisions with motorized
vehicles (Forman and Deblinger 2000; Trombulak and Frissell 2000; Inell et al.
2003; Van der Ree et al. 2011). These processes hinder the persistence of species in
human-dominated landscapes because small and isolated populations are more
vulnerable to extinction from stochastic demographic processes and loss of genetic
variation (Soule and Wilcox 1980).
Roads are perhaps the most widespread and pervasive form of “linear infrastructure” that have greatly impacted wildlife populations in the more developed
parts of the world through habitat loss, restriction of animal movements, alteration
of animal behaviour, and directly injuring or killing very large numbers of animals
in collisions with vehicles (Trombulak and Frissell 2000; Seiler and Helldin 2015).
A variety of animals are involved in road–kills, from large-bodied ones such as
moose to smaller creatures such as frogs (Fahrig et al. 1995; Formann et al. 2003;
Dorans et al. 2012). One estimate of road–kills suggested that 1,000,000 vertebrates
were killed in the USA every day (Lalo 1987), while Conover et al. (1995) estimated that the number of deer–vehicle collisions in the USA exceeds 1,000,000
annually, causing approximately 29,000 human injuries and 200 fatalities, apart
from animal fatalities. Given the magnitude of animal road–kills and the occurrence
of human fatalities, there has been much attention paid to mitigating wildlife road
kills through the appropriate design of roadways in many developed countries
(Clarke et al. 1998; Inell et al. 2003). In contrast, only limited attention has been
paid to wildlife–train collisions, although this has also been happening on significant scales in many countries. For instance, 200 moose train collisions were estimated in the province of British Columbia, Canada, during 1988–1990 (Child et al.
1991), with 266 collisions in a 92 km section of railways in Norway during 1980–
1988 (Andersen et al. 1991), and between 9 and 725 collisions annually in Alaska
(Modafferi 1991). Similarly, 69 roe deer train collisions in the Czech Republic were
reported during 2009 (Kusta et al. 2014). Therefore, there is an urgent need for
more information on train–wildlife collisions, and how these may be mitigated.
India is one of the countries with serious problems of train–wildlife collisions.
This is because the Indian Railways (IR) is one of the world’s largest railway
networks, comprising 115,000 km of tracks over a route of about 65,000 km and
158
M. Roy and R. Sukumar
Many animals range widely across landscapes in the quest to meet their daily,
seasonal and annual biological needs of food, water, shelter and mates (Caughley
and Sinclair 1994). Habitat connectivity within a landscape helps dispersal and
re-colonization, thus maintaining regional metapopulations and minimizing risks of
inbreeding within populations (Newmark 1987; Wilcove et al. 1998). Historically,
the spread of agriculture probably contributed the most to loss and fragmentation of
their natural habitat. In an increasingly industrialized world, however, transport
networks (railways, roads, and waterways) or so-called “linear infrastructures,”
restrict the movement of wildlife populations by fragmenting their habitat,
increasing edge effects, constricting ecological corridors, blocking animal movement, and increasing the risk of mortality due to direct collisions with motorized
vehicles (Forman and Deblinger 2000; Trombulak and Frissell 2000; Inell et al.
2003; Van der Ree et al. 2011). These processes hinder the persistence of species in
human-dominated landscapes because small and isolated populations are more
vulnerable to extinction from stochastic demographic processes and loss of genetic
variation (Soule and Wilcox 1980).
Roads are perhaps the most widespread and pervasive form of “linear infrastructure” that have greatly impacted wildlife populations in the more developed
parts of the world through habitat loss, restriction of animal movements, alteration
of animal behaviour, and directly injuring or killing very large numbers of animals
in collisions with vehicles (Trombulak and Frissell 2000; Seiler and Helldin 2015).
A variety of animals are involved in road–kills, from large-bodied ones such as
moose to smaller creatures such as frogs (Fahrig et al. 1995; Formann et al. 2003;
Dorans et al. 2012). One estimate of road–kills suggested that 1,000,000 vertebrates
were killed in the USA every day (Lalo 1987), while Conover et al. (1995) estimated that the number of deer–vehicle collisions in the USA exceeds 1,000,000
annually, causing approximately 29,000 human injuries and 200 fatalities, apart
from animal fatalities. Given the magnitude of animal road–kills and the occurrence
of human fatalities, there has been much attention paid to mitigating wildlife road
kills through the appropriate design of roadways in many developed countries
(Clarke et al. 1998; Inell et al. 2003). In contrast, only limited attention has been
paid to wildlife–train collisions, although this has also been happening on significant scales in many countries. For instance, 200 moose train collisions were estimated in the province of British Columbia, Canada, during 1988–1990 (Child et al.
1991), with 266 collisions in a 92 km section of railways in Norway during 1980–
1988 (Andersen et al. 1991), and between 9 and 725 collisions annually in Alaska
(Modafferi 1991). Similarly, 69 roe deer train collisions in the Czech Republic were
reported during 2009 (Kusta et al. 2014). Therefore, there is an urgent need for
more information on train–wildlife collisions, and how these may be mitigated.
India is one of the countries with serious problems of train–wildlife collisions.
This is because the Indian Railways (IR) is one of the world’s largest railway
networks, comprising 115,000 km of tracks over a route of about 65,000 km and
158
M. Roy and R. Sukumar