http://www.surinenglish.com/20161021/news/gibraltar/management-procedure-gibraltar-population

2016-11-06 10:00:00

The Barbary macaques of Gibraltar are famous but the population needs very careful management, not only because if they increase too much in number they can become a nuisance in built-up areas, but also because they are an endangered species. This was reflected in the recent uplisting of the species to Appendix I of the Convention on the Illegal Trade in Endangered Species of Wild Fauna and Flora.
The Gibraltar government does everything possible to avoid the need for extensive culls, which used to be the method used to control the macaque population in the past, and in recent years contraceptive implants have been used. However, these are of limited duration and are not 100 per cent effective.
Now the Macaque Management Team, which is run by the Department of the Environment and includes Gibraltar Ornithological & Natural History Society (GONHS) and the Gibraltar Veterinary Clinic, has introduced surgical contraception by way of laparoscopy.
Fifteen females have been treated so far from different groups of macaques on the Rock, all of which have already had one or more offspring in the past, so that they are not denied the opportunity of becoming mothers, which is important in macaque society.
The numbers of females sterilised in this way is also limited, so that there will always be some females within every group which will bear young.
This method will have the long term effect of stopping population growth, while allowing social structures to remain, and it does not threaten the continuation of the Gibraltar macaque population.source surinenglsih