Introduction
The development of large-scale transport infrastructure impacts surrounding
ecosystems. Environmental impact assessment is the formal procedure set up to
predict, evaluate, and plan for the mitigation or compensation of such impacts in
advance of project development (Petts 1999). Large projects impact various kinds of
species; those that affect animal populations, especially vertebrates, are prioritized
due to societal biases in conservation (Wilson et al. 2007). Nonetheless, the existing
knowledge about bird responses to the presence and operation of railways is extremely scarce, and the data are even more scarce with respect to high speed railways
(HSRs), due to their limited and relatively recent presence (Dorsey et al. 2015). Given
the expected expansion of these railways in the near future (Campos and de Rus 2009;
Todorovich et al. 2011; Fu et al. 2012), it is urgent that the environmental effects of
this new technology be assessed to enable the development of mitigation strategies.
There is now reliable information on the impacts of roads on wildlife and on birds
in particular (Benítez-López et al. 2010). We know that the effects are numerous,
beginning with habitat loss generated by the construction of the infrastructure.
However, the most serious impacts occur during the operating phase of roads, such as
direct mortality of individuals and indirect impacts derived from the degradation of
habitats close to roads. Similarly, railways alter bird communities both by destruction
and degradation of habitats, as well as by lethal collision (Spencer 1965; Mammen
et al. 2002). Due to the structural characteristics of HSRs (larger embankments,
catenaries, etc.), their structural effects on habitats (and thus on species) are expected
to exceed those of roads, while the degradation of habitats due to light, noise, and
pollution, as well as mortality, are expected to be smaller due to lower traffic intensity.
In any case, the effects of HSRs on birds will depend upon the individual responses
of species to the new landscape conditions. On the one hand, species will respond to
the presence of structures that alter the natural physiognomy of the area, including the
development of new habitats (e.g., revegetated embankments), and structural elements (e.g., catenaries, poles, bridges) that provide new potential perching and
nesting sites (Tryjanowski et al. 2013; Morelli et al. 2014). On the other hand, the risk
of mortality is restricted to birds that enter the narrow corridor where trains circulate,
where the habitat has undergone extreme modification, from the gravel ballast where
the rails lie to the catenary wires. To explain the impacts of future projects, it is crucial
to know how birds respond to the presence of the railway.
This chapter summarizes the results gathered during the monitoring of birds in an
agricultural area of the Iberian Peninsula that is crossed by a high-speed railway. We
present a sequential approach that addresses the presence, abundance, and activity
patterns of birds in the surroundings and on an HSR, complemented with data
addressing the response of birds facing approaching trains obtained through cockpit
video recordings.
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J.E. Malo et al.
The development of large-scale transport infrastructure impacts surrounding
ecosystems. Environmental impact assessment is the formal procedure set up to
predict, evaluate, and plan for the mitigation or compensation of such impacts in
advance of project development (Petts 1999). Large projects impact various kinds of
species; those that affect animal populations, especially vertebrates, are prioritized
due to societal biases in conservation (Wilson et al. 2007). Nonetheless, the existing
knowledge about bird responses to the presence and operation of railways is extremely scarce, and the data are even more scarce with respect to high speed railways
(HSRs), due to their limited and relatively recent presence (Dorsey et al. 2015). Given
the expected expansion of these railways in the near future (Campos and de Rus 2009;
Todorovich et al. 2011; Fu et al. 2012), it is urgent that the environmental effects of
this new technology be assessed to enable the development of mitigation strategies.
There is now reliable information on the impacts of roads on wildlife and on birds
in particular (Benítez-López et al. 2010). We know that the effects are numerous,
beginning with habitat loss generated by the construction of the infrastructure.
However, the most serious impacts occur during the operating phase of roads, such as
direct mortality of individuals and indirect impacts derived from the degradation of
habitats close to roads. Similarly, railways alter bird communities both by destruction
and degradation of habitats, as well as by lethal collision (Spencer 1965; Mammen
et al. 2002). Due to the structural characteristics of HSRs (larger embankments,
catenaries, etc.), their structural effects on habitats (and thus on species) are expected
to exceed those of roads, while the degradation of habitats due to light, noise, and
pollution, as well as mortality, are expected to be smaller due to lower traffic intensity.
In any case, the effects of HSRs on birds will depend upon the individual responses
of species to the new landscape conditions. On the one hand, species will respond to
the presence of structures that alter the natural physiognomy of the area, including the
development of new habitats (e.g., revegetated embankments), and structural elements (e.g., catenaries, poles, bridges) that provide new potential perching and
nesting sites (Tryjanowski et al. 2013; Morelli et al. 2014). On the other hand, the risk
of mortality is restricted to birds that enter the narrow corridor where trains circulate,
where the habitat has undergone extreme modification, from the gravel ballast where
the rails lie to the catenary wires. To explain the impacts of future projects, it is crucial
to know how birds respond to the presence of the railway.
This chapter summarizes the results gathered during the monitoring of birds in an
agricultural area of the Iberian Peninsula that is crossed by a high-speed railway. We
present a sequential approach that addresses the presence, abundance, and activity
patterns of birds in the surroundings and on an HSR, complemented with data
addressing the response of birds facing approaching trains obtained through cockpit
video recordings.
118
J.E. Malo et al.