Water-quality managers in Florida have some unwanted guests—the kind that move in and just won’t leave. It’s another example of an invasive species taking over an ecosystem. However, unlike kudzu—once thought to be an ideal plant for erosion control, and now ubiquitous in the Southeastern US—or the water hyacinth, a pretty ornamental that was introduced to the US at the 1884 Cotton States Exposition in New Orleans and soon spread out of control, this species has wings.
The purple swamphen, native to Asia, Africa, Europe, the Pacific islands—almost everywhere, it seems, but North and South America—is turning out to be an inconsiderate guest. Larger than many indigenous species, it’s bullying the local bird populations and outcompeting them for food and habitat. An article in the Miami Herald quotes a South Florida Water Management District scientist: “They’re really hardy, really adaptable, and eat whatever they want…. There’s no reason they couldn’t take over Florida.”
As with the water hyacinth, we know exactly when the birds were introduced, just 14 years ago. They’re attractive and colorful birds, once kept by the Romans as decorative pets, and some Florida residents apparently had the same idea. They allowed some of their captive swamphens to roam free, though; soon there were many more swamphens, and a decade later, in 2006, they were firmly established in one of the Everglades’ water conservation areas.
It’s uncertain how many of the birds now exist in the Everglades, but an attempt to hunt them several years ago in four of the water management district’s stormwater treatment areas yielded 3,000 birds, far more than the couple hundred the Florida Fish and Wildlife Conservation Commission was expecting. Scientists are now gathering information about their range, eating habits (the plants in the stormwater treatment areas are much to their liking, apparently), and reproduction so that they can plan the next move.