What is the bird on?
The bird is on the tree.
    src        edge_attr  dst
0     0  to the right of    7
1     0  to the right of    2
2     0  to the right of    1
3     0               of    3
4     0  to the right of   10
5     1   to the left of    0
6     2   to the left of    0
7     2               of    3
8     3               on    5
9     6  to the right of    7
10    6  to the right of   10
11    7   to the left of    0
12    7   to the left of    6
13   10   to the left of    6
14   10   to the left of    0