The trigger mechanism and metrics for establishing this success are still unclear.
Sliding up and down in the trough was a block, fitted with a trigger mechanism, through which passed the middle of the bowstring.
I had pressed down too hard on the trigger mechanism, in the heat of the battle, and this had jammed.
Inside the case was some sort of a trigger mechanism operated by a button on the outside.
The bird is caught when it alights on the trigger mechanism which snaps a noose as the bird perches on it.