annual loss of moose to train collisions in the winters between 1969 and 1982 was
estimated to range from several hundred to more than 1000 animals (Child 1983).
In Norway, the number of moose killed in train collisions has increased from
ca. 50 moose per year in the 1950s to a yearly average of 676 during 1990–1996.
This has resulted in economic costs due to material damages and loss of income due
to the lower number of hunting licenses issued (Gundersen and Andreassen 1998).
Jaren et al. (1991) estimated these costs at around $2900 per train-killed moose in
Norway. On average, 87 moose are killed along the Rørosbanen railway (Norway)
each year, which sums to a socio-economic loss of ca. $250,000 (Jaren et al. 1991).
Although in Alaska moose are considered common species within their range,
train kills accounted for 24% of known deaths, being the second cause of death in a
studied population (Modafferi and Becker 1997). During the winter of 1989–1990
there was a 35% reduction of the moose population in lower Susitna Valley,
Alaska, due to a combined effect of non-natural mortality and poor winter survival.
Although train collisions alone were not the only reason for that reduction, they
were the main cause of non-natural mortality (61.5%; 351 individuals). There was a
reduction of about 70% of moose numbers along this railway between 1984 and
1991, presumably due to high mortality on both the railway and the highway
(Modafferi and Becker 1997).
Some behaviours can contribute to this high mortality rate on railways. Moose
annually migrate from traditional summer areas to lower elevation winter areas with
snowfall determining the onset of these seasonal movements (Child 1983).
Wherever railways intercept and/or are parallel to areas occupied by moose, large
concentrations of animals may use the right-of-way of rails. Moreover, in winters
with above average snowfall, moose use the railways as travelling routes more
often, being more vulnerable to collisions (Child 1983; Gundersen et al. 1998;
Gundersen and Andreassen 1998; Rausch 1958). About 79% of moose train
accidents in Norway occurred from December to March, possibly due to their
migratory behaviour (Gundersen and Andreassen 1998).
As observed by Child (1983), moose can return rapidly to train tracks even after
a collision experience. A typical fatal event occurs when the animal attempts to
leave the tracks, but rapidly returns to the rail, probably because it is free of snow,
and then try to escape the approaching train by running on the rail. Sometimes
moose show an aggressive behaviour, standing in front of the train and attacking the
locomotive, with fatal consequences (Child 1983).
The factors influencing moose collision risk were studied by Gundersen and
Andreassen (1998) who found that trains running at night, in the morning or in the
evening had a higher risk of moose collision than daytime trains. The probability of
collision was also higher during nights of full moon. This could be partially
explained by the higher moose activity in those periods (Gundersen and Andreassen
1998). In a parallel study, it was found that the collisions increased in winter with
increasing snow depth and ambient temperatures below 0 °C, and were located in
the outlets of side valleys (Gundersen et al. 1998). The increase in the food
availability close to the railways due to logging activities also increased the number
of moose collisions (Gundersen et al. 1998).
2 Current Knowledge on Wildlife Mortality in Railways
13
estimated to range from several hundred to more than 1000 animals (Child 1983).
In Norway, the number of moose killed in train collisions has increased from
ca. 50 moose per year in the 1950s to a yearly average of 676 during 1990–1996.
This has resulted in economic costs due to material damages and loss of income due
to the lower number of hunting licenses issued (Gundersen and Andreassen 1998).
Jaren et al. (1991) estimated these costs at around $2900 per train-killed moose in
Norway. On average, 87 moose are killed along the Rørosbanen railway (Norway)
each year, which sums to a socio-economic loss of ca. $250,000 (Jaren et al. 1991).
Although in Alaska moose are considered common species within their range,
train kills accounted for 24% of known deaths, being the second cause of death in a
studied population (Modafferi and Becker 1997). During the winter of 1989–1990
there was a 35% reduction of the moose population in lower Susitna Valley,
Alaska, due to a combined effect of non-natural mortality and poor winter survival.
Although train collisions alone were not the only reason for that reduction, they
were the main cause of non-natural mortality (61.5%; 351 individuals). There was a
reduction of about 70% of moose numbers along this railway between 1984 and
1991, presumably due to high mortality on both the railway and the highway
(Modafferi and Becker 1997).
Some behaviours can contribute to this high mortality rate on railways. Moose
annually migrate from traditional summer areas to lower elevation winter areas with
snowfall determining the onset of these seasonal movements (Child 1983).
Wherever railways intercept and/or are parallel to areas occupied by moose, large
concentrations of animals may use the right-of-way of rails. Moreover, in winters
with above average snowfall, moose use the railways as travelling routes more
often, being more vulnerable to collisions (Child 1983; Gundersen et al. 1998;
Gundersen and Andreassen 1998; Rausch 1958). About 79% of moose train
accidents in Norway occurred from December to March, possibly due to their
migratory behaviour (Gundersen and Andreassen 1998).
As observed by Child (1983), moose can return rapidly to train tracks even after
a collision experience. A typical fatal event occurs when the animal attempts to
leave the tracks, but rapidly returns to the rail, probably because it is free of snow,
and then try to escape the approaching train by running on the rail. Sometimes
moose show an aggressive behaviour, standing in front of the train and attacking the
locomotive, with fatal consequences (Child 1983).
The factors influencing moose collision risk were studied by Gundersen and
Andreassen (1998) who found that trains running at night, in the morning or in the
evening had a higher risk of moose collision than daytime trains. The probability of
collision was also higher during nights of full moon. This could be partially
explained by the higher moose activity in those periods (Gundersen and Andreassen
1998). In a parallel study, it was found that the collisions increased in winter with
increasing snow depth and ambient temperatures below 0 °C, and were located in
the outlets of side valleys (Gundersen et al. 1998). The increase in the food
availability close to the railways due to logging activities also increased the number
of moose collisions (Gundersen et al. 1998).
2 Current Knowledge on Wildlife Mortality in Railways
13