Are these animals of different species?
No, all the animals are horses.
    src        edge_attr  dst
0     0   to the left of   15
1     0               on    3
2     0  to the right of    6
3     0  to the right of    5
4     0  to the right of   17
5     1               of    3
6     1   to the left of   18
7     1  to the right of    7
8     1   to the left of    8
9     2  to the right of    5
10    2  to the right of    6
11    3  to the right of    9
12    3  to the right of   16
13    5               on    6
14    5   to the left of    2
15    5   to the left of    0
16    6   to the left of   13
17    6   to the left of    2
18    6   to the left of    0
19    7  to the right of    9
20    7   to the left of   18
21    7   to the left of    1
22    7               of   14
23    8  to the right of    1
24    8               of    3
25    8  to the right of   14
26    8  to the right of   18
27    9   to the left of    3
28    9   to the left of    7
29    9               of   14
30   11               of   14
31   12               on    2
32   13  to the right of    6
33   13  to the right of   17
34   14   to the left of    8
35   14   to the left of   15
36   14   to the left of   18
37   15  to the right of    0
38   15  to the right of   14
39   16   to the left of    3
40   16   to the left of   17
41   17  to the right of   16
42   17   to the left of    0
43   17   to the left of   13
44   18  to the right of    1
45   18   to the left of    8
46   18  to the right of    7
47   18               of    3
48   18  to the right of   14