macaques

From: AR-News

Even though humane population control is possible -- and despite objections
from leading primatologists and the Gibraltar Ornithological and Natural
History Society -- the government of Gibraltar has embarked upon the culling
of Barbary macaques.  [For more information, please see the news article
appended further below.]

Please write to the government of Gibraltar's Environmental Agency and
Tourist Board in protest of the killing of Barbary macaques.  Ask that
Gibraltar immediately implement humane sterilization techniques to prevent
the monkeys from overpopulating and being deemed "nuisances".  Ironically,
these "nuisances" are one of the biggest tourist attractions for Gibraltar,
so be sure to let them know that you will not visit Gibraltar as long as
they are killing the monkeys.

I don't understand this. If you're just going to sterlize monkeys, then why not kill them?
That just gets the ultimate job done sooner.
Is it just that you, as tourists, want to enjoy the nut-chopped macaques before their much-more-anticipated, ultimate demise?