Snail Kites Move North as Health of Lake O & the Everglades Wane
While Florida’s endangered snail kite has rebounded a bit, the native species of snail it lives off has not. So the snail kite is changing its diet and moving on from its long-time habitat in the Everglades and Lake Okeechobee.
The snail kite is a bird of prey that, until very recently, was only found in South Florida. And the snail kite, also until very recently, has eaten one thing: Florida’s native apple snail, which the snail kite has uniquely evolved to be able to eat.
Back in the year 2000, there were about 3,000 of the birds in the state, but by 2010, their population had decreased to just 700. The apple snail, which is their only source of food, was disappearing with drought.
Then came a new, invasive, exotic apple snail that is bigger than our native Florida apple snail.
"They're just like a native snail on steroids. These exotic snails have been very resistant to the water management problems we have," said Science Coordinator for Audubon Florida's Everglades restoration program Paul Gray.
The snail kite population has rebounded to between two and 3,000, as the snail kite has started living off the invasive exotic snail species. While that sounds positive, our native apple snail isn't doing very well. According to Gray, that could be a reflection of the overall health of Lake Okeechobee and the ecosystem south through the Everglades.
"Unfortunately, like last year, it was very, very dry in spring and Lake Okeechobee didn't have a single snail kite nest on it and neither did the Everglades," said Gray.
"And so the population estimate last year declined by about maybe 20%."
Gray says if the snail kites can’t find enough food to feed themselves or their babies, they simply won’t nest, but as the invasive snails have moved North, the snail kites have followed, and are now living along the Gulf rim all the way to Louisiana, and the number one nesting site in the entire state most recently was Paynes Prairie, near Gainesville.
"Prior to that we'd never really had any records of kites nesting in that area at all. And then suddenly, there were a lot of nests up there because of the invasion of these exotic apple snails. So, their distribution around the state has changed because the snails can inhabit places that our native snails didn't inhabit," said Gray
Lake Okeechobee is listed as a critical habitat for Snail kites. Gray says that the U.S. Army Corps of Engineers’ proposals for Lake O, which plan to keep the lake at a much higher level than previously, may be concerning because when there was deep water in the Lake before it eliminated snail kite nesting.
"The trade off for that is if we decide we don't want the Lake to get too deep and endanger kites, then you have to get the water out of the Lake, and the only way to do that is … to dump the water down to the Caloosahatchee and St. Lucie estuaries. And of course everybody knows that that can cause severe harm to those estuaries," said Gray.
Gray notes that when the Lake hit 17 feet after Hurricane Irma, an entire plant zone was almost lost and still has not recovered nearly four years later. The native snail was part of that loss.
"The native snail is one of those things that is going to tell us if we have the water right or if we don't by their abundance," said Gray.
He suggests people advocate for healthy ecosystems and Everglades restoration to keep the snail kite, and its food source, the native apple snail, healthy.
"People come from all over the United States just to see snail kites. They're actually kind of dainty and they have really broad wings because they're hunting for a snail, you know, snails are fast. And so they can glide really, really slowly over the water. Because they have such broad wings. And I mean, it looks like they're only going 10 miles an hour and just about any other bird on the planet would fall out the sky because their wings wouldn't be big enough to float them, but snail kites can do that. So they're just a really cool bird that is just one of those unique things that we have in Florida, that people all come from all around to see, so it's fun to have them, but it's also kind of scary, because we have to make sure we don't screw it up and lose them by bad water management," said Gray.