From August 2020 to February 2021, the Monkey Management Project focused on researching the abundance and status of the invasive vervet monkey (Chlorocebus pygerythrus) to establish sustainable and humane solutions to manage their growing population, in order to protect St. Maarten’s native species and local agriculture.

The Monkey Management Project (full title “The Nature Foundation St. Maarten Explores Different Management Solutions for the Invasive Vervet Monkey Population on Sint Maarten“) aimed to research the current invasive vervet monkey troop population on St. Maarten and their effects on the environment in order to develop recommendations and guidelines to manage their populations. The project also focused on obtaining public opinion of the monkeys through two resident-targeted surveys, and worked to educate the island’s residents about invasive species and their impact on St. Maarten’s ecosystems.

The Monkey Management Project was introduced by the Nature Foundation St. Maarten and funded via the Resources for Community Resilience (R4CR) grant scheme. The R4CR program is a grant scheme that focuses exclusively on financing and strengthening of local Civil Society Organization (CSOs). The program is financed by the Government of the Netherlands via the St. Maarten Trust Fund. The latter is administered by the World Bank, implemented by the NRPB (National Recovery Program Bureau) and executed by VNGI (the Vereniging van Nederlandse Gemeenten International) in close cooperation with Foresee Foundation-NPOwer and other local partners.


St. Maarten had its first recorded wild vervet monkey sighting in the 1970s. Since then, the island’s invasive monkey has grown exponentially, with an estimated 450 vervet monkeys living in Dutch St. Maarten. These monkeys are highly concentrated in the evergreen vegetation seen on St. Maarten’s hilltops. The surrounding hillside residences and businesses deal with the presence of monkeys year-round, especially during the dry season.

Without natural predators present, their population can rapidly double within a year. This species can cause irreversible damage to a variety of wildlife, including endangered native flora and fauna. Monkeys also cause extensive damage to the vegetation they live in and consume. If the vervet monkey population continues to increase uncontrolled, the native and transient bird populations are likely to decrease.

Food security is currently very challenging to achieve given the significant monkey-caused challenges local farmers must handle. Agriculturists on the island have spoken frequently about issues with monkeys raiding and destroying especially their crops or disturbing their livestock. This issue is heightened during the dry season on St. Maarten when wild food sources are scarce, resulting in large groups of monkeys descending on valuable croplands and raiding valuable fruit and vegetable crops.

Safety issues have also become pronounced as St. Maarten’s monkeys familiarize themselves with humans and become bolder in approaching residents, schools, and businesses in search of food. Throughout the Monkey Management Project conducted by the Nature Foundation in 2021, there were several reports about the monkeys entering private gardens with residents and children feeling endangered. Health concerns are also imminent considering their close relation to humans and possibility of disease transfer.