It took decades for this endangered bird to reclaim its habitat.
The snail kite, one of Florida’s most imperiled birds, appeared to be in the midst of a complicated success story after Hurricane Irma flooded Paynes Prairie in 2017. The high water created new habitat for wildlife and allowed an invasive aquatic snail species to continue creeping into northern Florida. The uniquely adapted snail kites followed.
But the endangered snail kite might not hang on much longer.
The water levels at Paynes Prairie never stay steady for too long -- rising and falling with changing conditions. Snail kites rely on wetlands. And right now, water levels are falling quickly. The snail kite population peaked at 151 birds in April 2020, before dipping to less than five in May 2021 as their new hunting grounds dried up.
Snail kites were nearly eradicated from the state after years of wetland and water quality degradation. In the early 1900s, they were common in south and central Florida’s undisturbed wetland areas where they hunted apple snails — a gooey delicacy that accounts for the majority of their diet. As Florida drained its marshes and contaminated fragile waterways during the mid-century development boom, snail kites retreated to the Everglades and vanished from their historic breeding grounds.
Caroline Poli was the first to spot a snail kite on Paynes Prairie after Hurricane Irma; it was only the eighth sighting in Alachua County since 1985. A visiting friend had invited her to Sweetwater Wetlands Park on a work day, but that didn’t keep Poli from getting out there.
“I never turn down an opportunity to go birding,” said Poli,a snail kite researcher and postdoctoral associate at the University of Florida.
Her snail kite sighting was unexpected, and so was the arrival of more birds in the following weeks.
But Poli wasn't surprised.
Paynes Prairie is one of the biggest wetlands in north Florida that remains intact, and it has ideal habitat for snail kites. Of course, they need a large aquatic snail population to survive and the invasive apple snails had already made their way from south Florida to Paynes Prairie through the state's connected waterways. The kites also need a mix of open and vegetated water for foraging in addition to dead willow trees -- their preferred nesting grounds.
“When you have good prey and good hydrology, you have all the good conditions for a kite to nest and hang out year-round,” Poli said.
As it turns out, the birds aren’t bothered by the bulky invasive snails — which grow up to three times larger and produce 300 times more eggs than the native apple snails. Snail kites have large talons specifically evolved to snatch floating snails, and a deeply curved beak to sever the body from the shell.
While they appear to have overcome invasive prey, other factors challenge their ability to re-establish a stable population and lift them from endangered status. Invasive plant species have wreaked havoc on Florida’s wetlands, causing chemical and biological imbalances. For the kites, the dense vegetation makes it difficult to see the snails from the sky and increases the risk of predators in their nests, according to Poli.
Poli also identified the lack of comprehensive wetland management as a threat to existing snail kite populations. Wetland systems naturally change over time and without a network of protected wetlands in an area, snail kites would have nowhere to go if their existing home dries up — like what is currently happening in Paynes Prairie.