Invasive snails are helping an endangered bird make a comeback in Florida | 24CA News

Since island apple snails invaded the Florida Everglades, an endangered species of chook often called the snail kite has bounced again from the specter of extinction.

It’s a uncommon case of a damaging invasive species having a constructive influence, says Robert Fletcher, a professor of panorama ecology on the University of Florida who additionally directs a snail kite monitoring program.

“There was a lot of concern that this bird that was already endangered was really on the brink of extinction. And then entered this non-native snail,” Fletcher instructed As It Happens host Nil Köksal.

The Everglade snail kite is a hawk-like raptor that depends on wetland ecosystems to feed nearly solely on Florida apple snails.

In the early 2000s, extreme droughts within the Everglades brought about the inhabitants of those native apple snails to dissipate. And since snail kites relied on them as their sole meals supply, their numbers plunged from greater than 3,000 birds within the late ’90s to roughly 700 in 2009, in response to a 2022 report by the conservation group Audubon Florida.

Birds adapt to new prey

Cue the non-native island apple snail.

After they confirmed up within the southeastern United States, the snail kite inhabitants in Florida bounced again to roughly 3,000 birds right now.

But when the non-native snail was first noticed in 2004, Fletcher mentioned folks have been very apprehensive that it was “going to exacerbate the extinction risk of [the snail kite] and essentially really push it even closer to extinction.” 

The major concern was that these non-native snails have been as much as 5 instances larger than what the birds have been used to capturing with their talons and extracting with their payments. 

“Scientists quickly saw snail kites trying to forage on this non-native snail, but they were largely unsuccessful. They would drop the snails quite often,” Fletcher mentioned.

Once the non-native snails had expanded by means of a lot of the Everglades and overtaken the native ones, nonetheless, the snail kite inhabitants started to rise.

And the birds who bred in wetlands with the invasive snails fared much better than birds compelled to outlive with out them as a supply of meals, says Fletcher.

“It was incredibly surprising,” he mentioned. “We couldn’t understand how the birds were handling such large snails.”

He and his college students had been monitoring the snail kites for years, banding them as they fled from their nests with the intention to measure many issues about them, together with the dimensions of their payments.

The information they’d been accumulating confirmed their payments have been getting larger yearly with the intention to accommodate the baseball-sized snails.

What this implies for the native ecosystem 

Samuel Chan, an invasive species knowledgeable at Oregon State University, says the island apple snail from South America doubtless obtained free and established themselves in Florida by means of the pet or aquarium commerce. Since this species of snail was extra resilient to dry circumstances, it out-competed the native species and took over.

Although the snail kite’s rising restoration is nice news, it seems to be nearly utterly based mostly on the prevalence of unique snails, Chan mentioned. The dangerous news, he added, is the native snails haven’t made a comeback. 

“I think the birds are telling us a story about what’s missing in their habitat,” he mentioned. “The reality is that this invasive species is filling a hole, but there will be repercussions in other layers of the ecosystem.” 

Chan referred to the non-native island apple snail as a “surrogate” meals supply for the snail kites, which have tailored their feeding as a survival technique. 

“But a surrogate host can’t be a solution. It’s not just saving the snail kites; it’s doing other things, too. And that’s the part that is worrisome. The surrogate is not going to stay still,” Chan mentioned.

Fletcher admits it is a difficult scenario and he additionally has considerations in regards to the potential influence the species can have on the Everglades in the long run. 

While the island apple snail might look like saving the snail kite, it’s identified to be damaging, Fletcher says. It has decimated agricultural fields and feasted on aquatic vegetation in lots of areas of the world.

“It’s a tricky one,” he mentioned, “because depending on the situation, there can be lots of lots of consequences when new species come into areas — but sometimes there can be benefits.”

Fletcher and Chan each seek advice from the Florida apple snail inhabitants as a barometer for the well being of the native ecosystem.

In order for the snail kite’s comeback story to have a contented ending, says Chan, native range and resilience is required. If the endangered chook continues to rely solely on non-native invaders, there might be detrimental impacts on its ecosystem.

“If we’re going to recover the native snail kite, we need to recover the native snail,” he mentioned.