Also in 2004–2015, we found that the occurrence of elephant–train collisions
varied markedly during the daily cycle. In fact, most accidents occurred between
midnight and 6:00 and 16:00–24:00, with peaks at 01:00–2:00 and 22:00–23:00
(Fig. 10.2). More accidents occurred during the night (80%), and this was significantly higher than during the day (Z = 3.198, P = 0.002). There were also significant seasonal patterns in the number of accidents (Kruskal–Wallis H = 12.69,
P = 0.05) and the number of elephant deaths (Kruskal–Wallis H = 39.70,
P = 0.05), with both occurring most frequently during the paddy cultivation season,
followed by maize and non-crop seasons (Fig. 10.3). The association of accidents
with elephants with the crop cultivation seasons is further emphasized by the strong
correlation between the monthly proportion of elephants killed and the frequency of
crop raiding by elephants in villages (all seasons: r = 0.38, P = 0.11; maize season:
r = 0.81, P = 0.025; paddy season: r = −0.037, P = 0.47). In fact, there were
Table 10.2 Age structure of the elephant population in northern West Bengal (based on Sukumar
et al. 2003) and those killed in train elephant collisions in the Siliguri–Alipurduar railway between
2004 and 2015
Age class
% Females
in population
% Females killed in
train accidents
% Males in
population
% Males killed
in train accidents
Adult
33.3
29.0
12.9
30.6
Sub-adult
11.1
11.3
12.3
8.1
Juvenile
13.5
4.8
8.8
0.0
Calves
4.1
8.1
4.1
8.1
Total
62.0
53.2
38.0
46.8
0.0
2.0
4.0
6.0
8.0
10.0
12.0
00:00-01:00
01:00-02:00
02:00-03:00
03:00-04:00
04:00-05:00
05:00-06:00
06:00-07:00
07:00-08:00
08:00-09:00
09:00-10:00
10:00-11:00
11:00-12:00
12:00-13:00
13:00-14:00
14:00-15:00
15:00-16:00
16:00-17:00
17:00-18:00
18:00-19:00
19:00-20:00
20:00-21:00
21:00-22:00
22:00-23:00
23:00-24:00
Percentage
Fig. 10.2 Temporal distribution of train–elephant collisions during the daily cycle from 2004
until 2015 (after broad gauge conversion), in the Siliguri–Alipurduar railway, northern West
Bengal, India
164
M. Roy and R. Sukumar
varied markedly during the daily cycle. In fact, most accidents occurred between
midnight and 6:00 and 16:00–24:00, with peaks at 01:00–2:00 and 22:00–23:00
(Fig. 10.2). More accidents occurred during the night (80%), and this was significantly higher than during the day (Z = 3.198, P = 0.002). There were also significant seasonal patterns in the number of accidents (Kruskal–Wallis H = 12.69,
P = 0.05) and the number of elephant deaths (Kruskal–Wallis H = 39.70,
P = 0.05), with both occurring most frequently during the paddy cultivation season,
followed by maize and non-crop seasons (Fig. 10.3). The association of accidents
with elephants with the crop cultivation seasons is further emphasized by the strong
correlation between the monthly proportion of elephants killed and the frequency of
crop raiding by elephants in villages (all seasons: r = 0.38, P = 0.11; maize season:
r = 0.81, P = 0.025; paddy season: r = −0.037, P = 0.47). In fact, there were
Table 10.2 Age structure of the elephant population in northern West Bengal (based on Sukumar
et al. 2003) and those killed in train elephant collisions in the Siliguri–Alipurduar railway between
2004 and 2015
Age class
% Females
in population
% Females killed in
train accidents
% Males in
population
% Males killed
in train accidents
Adult
33.3
29.0
12.9
30.6
Sub-adult
11.1
11.3
12.3
8.1
Juvenile
13.5
4.8
8.8
0.0
Calves
4.1
8.1
4.1
8.1
Total
62.0
53.2
38.0
46.8
0.0
2.0
4.0
6.0
8.0
10.0
12.0
00:00-01:00
01:00-02:00
02:00-03:00
03:00-04:00
04:00-05:00
05:00-06:00
06:00-07:00
07:00-08:00
08:00-09:00
09:00-10:00
10:00-11:00
11:00-12:00
12:00-13:00
13:00-14:00
14:00-15:00
15:00-16:00
16:00-17:00
17:00-18:00
18:00-19:00
19:00-20:00
20:00-21:00
21:00-22:00
22:00-23:00
23:00-24:00
Percentage
Fig. 10.2 Temporal distribution of train–elephant collisions during the daily cycle from 2004
until 2015 (after broad gauge conversion), in the Siliguri–Alipurduar railway, northern West
Bengal, India
164
M. Roy and R. Sukumar