UF Model Predicts Potential Results of Macaque Population Control Methods

Newswise — GAINESVILLE, Fla. --- Recent laboratory research established that rhesus macaques – a type of monkey – in Silver Springs State Park host a virus that can pose ecological and human health threats. Although no one has been reported to have contracted a virus from a wild macaque, including those in the Florida park, the monkeys pose a danger to native species and humans in the park and in adjacent areas, say University of Florida researchers.

As of three years ago, about 175 macaques were estimated to live in the park. Without intervention, the population will increase to about 350 by 2022, according to a new UF Institute of Food and Agricultural Sciences study.

Because macaques pose a danger to native species and people, UF/IFAS researchers wanted to know how many primates would remain in Silver Springs State Park if various population control methods were adopted.

In the new study, published in The Journal of Wildlife Management, UF/IFAS researchers tested possible ways to control the population of rhesus macaques at the park, including physically removing them or sterilizing female macaques. Scientists used computer models to test how many macaques would remain in the park under various population reduction methods.

Among other results, the UF/IFAS scientists showed that if park managers want to eventually eliminate the macaques from the park, they could remove at least half of the primates every other year. A second alterative, sterilizing at least half the adult females every two years, could cut the population to one third its current size, the study showed.

Without reducing the macaque population, the animals are more apt to interact with people, said Steve Johnson, a UF/IFAS associate professor of wildlife ecology and conservation and co-author of the study. Higher macaque populations increase the possibility of harm to humans, researchers say.

“The population is just going to grow, and the frequency of the problems is going to grow, and it increases the possibility of the monkeys going outside the park,” Johnson said. If monkeys get out of the park, they’re even more likely to interact with people, which poses further dangers. For instance, they might bite people in neighboring areas, Johnson said.

It’s important to note that the study included macaques living within the confines of Silver Springs State Park, not the ones living near the park, said Jane Anderson, a wildlife ecology and conservation doctoral alumna of the UF/IFAS College of Agricultural and Life Sciences who led the study as part of her doctoral research.

“In order for these management strategies to be fully effective, they would also need to be applied to macaques around the park,” Anderson said. “It is possible if the macaques are removed from the park and not elsewhere, macaques could move into the park from surrounding areas.”

In addition to human interactions, macaques can threaten the park’s ecology, although Johnson said researchers don’t know the potential magnitude of that yet.

The Florida Department of Environmental Protection would decide how and whether to control the macaque population at Silver Springs State Park.

UF/IFAS researchers are communicating with the FDEP about their research, but Johnson said he doesn’t know what, if anything, state officials will do with the population control models.

“This provides them with some guidance,” Johnson said. “For example, if you do this particular action, this is likely what you’d see. They’d have to decide from there.”

Meanwhile, here’s Johnson’s best advice: Look at macaques, but don’t feed them, and in general, avoid them.

For more information about Florida’s history with rhesus macaques, click here.

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By: Brad Buck, 352-294-3303, [email protected]

The mission of the University of Florida Institute of Food and Agricultural Sciences is to develop knowledge relevant to agricultural, human and natural resources and to make that knowledge available to sustain and enhance the quality of human life. With more than a dozen research facilities, 67 county Extension offices, and award-winning students and faculty in the UF College of Agricultural and Life Sciences, UF/IFAS works to bring science-based solutions to the state’s agricultural and natural resources industries, and all Florida residents. Visit the UF/IFAS web site at ifas.ufl.edu and follow us on social media at @UF_IFAS.