abundant either close to or far from the railway albeit not significantly so but this
often varied across the tidal and annual cycles. Overall, our study did not find
noticeable exclusion effects of this railway on wetland birds, with spatial variation
in abundances probably reflecting habitat selection and daily movement patterns.
Information is needed on other study systems to assess the generality of our
findings.
Keywords Aquatic birds Á Habitat loss Á Human disturbance Á Environmental
impact Á Transportation infrastructures Á Zone of influence
Introduction
Linear transportation infrastructures such as roads and railways are increasing
worldwide, and this is generally considered a serious threat to wildlife conservation
(van der Ree et al. 2015). Transportation infrastructure networks are particularly
dense in developed countries, with a recent study showing that in Europe about
50% of the land area is within 1.5 km of a paved road or railway line (Torres et al.
2016). This problem also increasingly affects less developed countries, where most
infrastructure and urban development is expected to take place over the coming
decades (Seto et al. 2012). Therefore, there is an urgent need to evaluate the impacts
of linear infrastructure development on wildlife, and to devise planning and technical solutions to mitigate such impacts (DeFries et al. 2012).
The impacts of linear transportation infrastructures are generally associated with
direct mortality caused by animal collisions with circulating vehicles (Loss et al.
2015; Santos et al. 2016), and with barrier effects and the consequent increases in
habitat fragmentation and reduced landscape connectivity (Carvalho et al. 2016).
However, there may also be widespread indirect habitat degradation, because many
animal species avoid using areas close to transportation infrastructures (Forman and
Deblinger 2000; Torres et al. 2016). For instance, a recent study showed that many
bird species strongly avoided traffic noise, while certain others remaining close to
noisy environments exhibited degradation in body condition (Ware et al. 2015).
Another study showed that even unpaved roads reduced herbivore densities in a
protected area (D’Amico et al. 2016). Most of these studies, however, have focused on
roads, either ignoring railways or assuming that roads and railways have largely
similar impacts (e.g. Torres et al. 2016). Furthermore, the few studies available are
contradictory (see Chap. 6), with some pointing out negative effects of noise, lights
and vibrations associated with circulating trains, while others suggest that wildlife
ignore or adapt to railway disturbance (Owens 1977; Waterman et al. 2002; Gosh et al.
2010; Li et al. 2010; Mundahl et al. 2013; Wiacek et al. 2015). Thus, more information
is needed on the exclusion effects of railways, particularly on the species and ecological conditions associated with the most negative effects.
If railways have strong exclusion effects, their consequences may be particularly
serious when crossing wetland habitats. This is because wetlands are declining fast,
180
C. Godinho et al.
often varied across the tidal and annual cycles. Overall, our study did not find
noticeable exclusion effects of this railway on wetland birds, with spatial variation
in abundances probably reflecting habitat selection and daily movement patterns.
Information is needed on other study systems to assess the generality of our
findings.
Keywords Aquatic birds Á Habitat loss Á Human disturbance Á Environmental
impact Á Transportation infrastructures Á Zone of influence
Introduction
Linear transportation infrastructures such as roads and railways are increasing
worldwide, and this is generally considered a serious threat to wildlife conservation
(van der Ree et al. 2015). Transportation infrastructure networks are particularly
dense in developed countries, with a recent study showing that in Europe about
50% of the land area is within 1.5 km of a paved road or railway line (Torres et al.
2016). This problem also increasingly affects less developed countries, where most
infrastructure and urban development is expected to take place over the coming
decades (Seto et al. 2012). Therefore, there is an urgent need to evaluate the impacts
of linear infrastructure development on wildlife, and to devise planning and technical solutions to mitigate such impacts (DeFries et al. 2012).
The impacts of linear transportation infrastructures are generally associated with
direct mortality caused by animal collisions with circulating vehicles (Loss et al.
2015; Santos et al. 2016), and with barrier effects and the consequent increases in
habitat fragmentation and reduced landscape connectivity (Carvalho et al. 2016).
However, there may also be widespread indirect habitat degradation, because many
animal species avoid using areas close to transportation infrastructures (Forman and
Deblinger 2000; Torres et al. 2016). For instance, a recent study showed that many
bird species strongly avoided traffic noise, while certain others remaining close to
noisy environments exhibited degradation in body condition (Ware et al. 2015).
Another study showed that even unpaved roads reduced herbivore densities in a
protected area (D’Amico et al. 2016). Most of these studies, however, have focused on
roads, either ignoring railways or assuming that roads and railways have largely
similar impacts (e.g. Torres et al. 2016). Furthermore, the few studies available are
contradictory (see Chap. 6), with some pointing out negative effects of noise, lights
and vibrations associated with circulating trains, while others suggest that wildlife
ignore or adapt to railway disturbance (Owens 1977; Waterman et al. 2002; Gosh et al.
2010; Li et al. 2010; Mundahl et al. 2013; Wiacek et al. 2015). Thus, more information
is needed on the exclusion effects of railways, particularly on the species and ecological conditions associated with the most negative effects.
If railways have strong exclusion effects, their consequences may be particularly
serious when crossing wetland habitats. This is because wetlands are declining fast,
180
C. Godinho et al.