Towards a Resilient and Environmentally Sustainable Island by Improving Management of the Invasive Monkey Population on St. Maarten

Student Report

The Monkey Management Project was developed by the Nature Foundation St. Maarten and funded by Resources for Community Resilience (R4CR). The project focused on researching the abundance and status of the invasive vervet monkey (Chlorocebus pygerythrus) and to establish sustainable and humane solutions to manage the invasive monkey population to protect St. Maarten’s native species and local agriculture. The project was guided by the results from the preliminary online survey conducted in August and September 2020 which included the areas the monkeys are most likely seen by respondents. Field research was executed in January and February 2021, to collect data from the monkeys on the island, using a rapid assessment of 10-minute instantaneous scan sampling. A Management Options Survey was conducted to further educate St. Maarten residents on the monkeys and the possible management solutions, and to allow them to provide their opinion on which of these solutions should be implemented on St. Maarten. Observations from the field research reflected data that differed from expected results, including lower numbers of monkeys recorded than expected to be seen during the early morning and evenings. This indicates underestimated numbers of monkeys sighted during the field research. The research shows that most monkeys are located in Point Blanche hill area, but also Guana bay, Sentry hill and Dawn beach hill areas showed high amounts of sighted monkeys. Over half of the respondents from the Management Option Survey decided eradication was the best option for St. Maarten, and a third of respondents decided that sterilization was the best option. Based on the results from the field research, and Management Options Survey, it is estimated that 6 up to 9 troops are located on the Dutch side of the island and each troop existing of 10 up to 50 monkeys. Due to this information collected, the Nature Foundation St. Maarten recommends humane euthanasia to be applied to effectively manage the invasive vervet monkey population. The Foundation recommends making the funds available and starting the process as soon as possible to prevent deterioration of the monkey situation or have residents take matters into their own hands.

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