the current Asiatic wild ass distribution because no wild ass has been observed on
the eastern side for many years, despite the existence of suitable habitat on the
northeastern side of the railway (Kaczensky et al. 2011b, 2015). Further data on
tracked Mongolian gazelles have confirmed that the railway impeded 24 gazelles
tracked between 2002 and 2012 from crossing to both sides (Fig. 14.6; Ito et al.
2013a), except for one individual (Olson 2012).
International border fences further exacerbate the fragmentation of the landscape
and have a similar barrier effect on wild ungulates. Almost none of the tracked
ungulates in Mongolia crossed the borders (Fig. 14.6; Ito et al. 2013a; Kaczensky
et al. 2006, 2008, 2011a; Olson 2012; Olson et al. 2009b), except for one reported
case of an Asiatic wild ass in western Mongolia (Kaczensky et al. 2011a). These
results indicate that the railway and the border fences are likely causes of habitat
fragmentation and impediments to long-distance movements of ungulates.
Influences of the Barrier Effect on Wild Ungulates
What are the problems caused by railway barrier effects on wild ungulates?
Although the railway bisects Mongolia’s Gobi-Steppe Ecosystem, each part of the
ecosystem is still vast. The seasonality of the ungulates’ location is a key to
evaluate how the railway influences the animals restricted to one side of this barrier.
Tracked Mongolian gazelles and Asiatic wild asses used areas far from the barriers
during summer but used areas close to the railway and the borders during winter
(Fig. 14.7; Ito et al. 2005, 2013a). The only case of a tracked wild ass crossing the
border to China and returning to Mongolia was observed during the harsh winter
Fig. 14.5 Average
normalized-difference
vegetation index (NDVI) in
each zone adjacent to the
railway from 17 November to
2 December 2002. Error bars
represent 95% confidence
intervals. See Fig. 14.3 for
explanation of zone names
(from Ito et al. 2005)
14 Habitat Fragmentation by Railways as a Barrier to Great …
237
the eastern side for many years, despite the existence of suitable habitat on the
northeastern side of the railway (Kaczensky et al. 2011b, 2015). Further data on
tracked Mongolian gazelles have confirmed that the railway impeded 24 gazelles
tracked between 2002 and 2012 from crossing to both sides (Fig. 14.6; Ito et al.
2013a), except for one individual (Olson 2012).
International border fences further exacerbate the fragmentation of the landscape
and have a similar barrier effect on wild ungulates. Almost none of the tracked
ungulates in Mongolia crossed the borders (Fig. 14.6; Ito et al. 2013a; Kaczensky
et al. 2006, 2008, 2011a; Olson 2012; Olson et al. 2009b), except for one reported
case of an Asiatic wild ass in western Mongolia (Kaczensky et al. 2011a). These
results indicate that the railway and the border fences are likely causes of habitat
fragmentation and impediments to long-distance movements of ungulates.
Influences of the Barrier Effect on Wild Ungulates
What are the problems caused by railway barrier effects on wild ungulates?
Although the railway bisects Mongolia’s Gobi-Steppe Ecosystem, each part of the
ecosystem is still vast. The seasonality of the ungulates’ location is a key to
evaluate how the railway influences the animals restricted to one side of this barrier.
Tracked Mongolian gazelles and Asiatic wild asses used areas far from the barriers
during summer but used areas close to the railway and the borders during winter
(Fig. 14.7; Ito et al. 2005, 2013a). The only case of a tracked wild ass crossing the
border to China and returning to Mongolia was observed during the harsh winter
Fig. 14.5 Average
normalized-difference
vegetation index (NDVI) in
each zone adjacent to the
railway from 17 November to
2 December 2002. Error bars
represent 95% confidence
intervals. See Fig. 14.3 for
explanation of zone names
(from Ito et al. 2005)
14 Habitat Fragmentation by Railways as a Barrier to Great …
237