Get an inside look at science as it happens in the Caribbean. This week, how do you know if something’s wrong in the local ecology, and how do you know what it is?
During a February 2017 field visit to St. Kitts and Nevis, I marveled at the forests. There were huge trees, hanging vines, graceful ferns and lush mosses. Still, while bursting with greenery, many areas seemed oddly lifeless. Anoles—the small tree lizards that are incredibly common in the Caribbean—seemed to be unusually scarce. Snails weren’t crawling across every damp leaf and tree trunk, they were almost absent.
Other members of the research team—experts on plants, reptiles, birds and more—noticed many similar anomalies. The heliconia plants were surprisingly rare, geckos that we would expect to find weren’t seen at all. Tiny moths and other insects that often erupt in clouds when walking through field or scrub seemed unaccountably sparse. Almost immediately, we were all wondering what was going on.
Our first intuition was to blame the monkeys. Vervet Monkeys from Africa were introduced to St. Kitts and Nevis in the 1600s. Smart and voracious, they’ve had hundreds of years to impact the local ecology. More importantly, they are the one thing that is most obviously different about St. Kitts and Nevis, compared to most other islands in the area. All the Lesser Antilles have rats, many have mongoose, but Barbados is the only other one that has had monkeys for centuries.
The intuition of a group of scientists with extensive research experience in the Caribbean is valuable, but it doesn’t prove anything. Implicating the monkeys would require data showing that ecosystems were damaged, and experiments to show that monkeys were the culprit. Although that is beyond the scope of our project, the data we collect could support the need to look further.
Another culprit had been upsetting the ecological balance over recent years as well. From a serious drought in 2015 to erratic rainfall in the years since, weather may have influenced what we observed. By the time we returned in May, the islands had received some spring rains. Lizards and snails still seemed less common than they should be, but the symphony of insect sounds at night seemed richer and fuller.
With specimens, data and observations collected across two field work sessions, interesting ideas about the ecology of St. Kitts and Nevis are bound to emerge. Do monkeys harm the local ecosystem? Almost certainly. Could animal and plant populations be temporarily lowered due to drought and rainfall irregularity? It’s definitely possible. Do St. Kitts and Nevis have less overall biodiversity that we might expect? Survey results should give us an idea. Most importantly, the data should give us ideas about what these islands can do to help preserve and protect their natural heritag