Fifteen female Barbary Macaques from the upper Rock have been sterilised by the Gibraltar Government in a bid to control the population without the use of extensive culling.
A government spokesman said that the control of the population, which is necessary in a small, densely populated area such as Gibraltar, is best carried out by other means.
“While contraceptive implants have been used for several years now, they are of limited duration and sometimes not 100% effective,” the spokesman said. “As of this autumn, the Macaque Management Team, run by the Department of the Environment and Climate Change which includes the GONHS and the Gibraltar Veterinary Clinic, has introduced surgical contraception by way of laparoscopy.”
Local veterinarian Mark Pizarro has so far treated fifteen female macaques from most of the groups found on the rock. The females are carefully selected by the team.
“They are always females who have already had one or more young in past years, so that they are not denied the opportunity of becoming mothers, which is important in macaque society,” the spokesman said. “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.”
The spokesman said that this method will have the long term effect of stopping population growth, while allowing social structures to remain and not threaten the continuation of the Gibraltar macaque population.
As an additional management tool, this year has also seen the start of a programme to carry out genetic fingerprinting of the whole macaque population of Gibraltar.
“Correct management of our Barbary macaques is essential, and not just to reduce the nuisance they can cause in built-up areas,” the spokesman said.
The species was recently ‘up-listed’ to Appendix I of the Convention on the Illegal Trade in Endangered Species of Wild Fauna and Flora.
This up-listing, which was supported by the International Primate Protection League, highlighted the importance of the species and Gibraltar as the primate’s refuge as numbers are dwindling in its North African habitat. Minister for the Environment and Climate Change Dr John Cortes was also consulted in his personal capacity as a macaque conservation biologist prior to making a decision.
“Having largely resolved the problem of macaques impacting on our built-up areas which, as I said at the time, required a few years of patient work,” he said. “We can now fine tune our management methods so that all of us can once again start to think of our monkeys, not as pests, but as an asset of which to be proud.”