Definition of cullers:
(v) :
To pick or take someone or something (from a larger group).
(v) :
To select animals from a group and then kill them in order to reduce the numbers of the group in a controlled manner.
(v) :
To lay off in order to reduce the size of, get rid of.
(v) :
To gather, collect.
(v) :
(by extension) To kill (animals, etc).
(n) :
A selection.