A University of Florida Institute of Food and Agricultural Sciences study shows that wildlife is moving because of climate change.
Piercing dark eyes gazed at bird enthusiasts and scientists at Paynes Prairie in April. The snail kite, an endangered species native to the Everglades, hadn’t been seen as far north as Gainesville for 100 years — until last year, that is.
Some research suggests climate change may play a role in the species’ new breeding grounds.
A recently published study by University of Florida researcher Brett Scheffers and Gretta Pecl of the University of Tasmania suggests that wildlife is on the move as a result of climate change, and Florida’s fauna seem to be following the observed trends.
“It’s not a thing of the future,” Scheffers said. “It’s happening now.”
The Nature Climate Change paper, “Persecuting, protecting or ignoring biodiversity under climate change,” discusses the different ways people have responded to species that have moved because of climate change.
Some, like the snail kite, are well-liked and heavily protected.
Robert Fletcher, a UF associate professor of wildlife ecology and conservation who studies the bird, said he and other researchers found four snail kite nests at Paynes Prairie last year, but this year dozens have been sighted.
“There’s a lot of birds that move north to come nesting at Paynes Prairie,” he said.
Fletcher said increased flooding and the introduction of the exotic apple snail, a food source for the bird, has contributed greatly to the species’ northward movement.
“It’s very much provided the conditions necessary for snail kites,” he said.
Fletcher said climate change is likely an indirect cause of snail kite movement into the area, causing extreme weather events such as the flooding that enable the snail kite, which nests directly over water, to put down roots.
Changing conditions have led to species population growth, Fletcher said, which gives him cautious optimism for the birds’ success.
“Those are all very promising signs,” he said. “But we still don’t know what will happen in the future.”
Scheffers, the study's author, said species that are not as well-liked, but are nevertheless on the move due to climate change, are often persecuted by society.
In South Florida, fewer instances of cold temperatures have led to a boom in the green iguana population.
Perry Colato, cofounder of Redline Iguana Removal in Hollywood, said the last record-breaking major cold snap in the area occurred in 2010, and since then, iguanas have been reigning supreme on South Florida golf courses, in yards and even in toilets.
“They’re anywhere and everywhere,” he said. “They don’t have any predators around here.”
The non-native, invasive reptiles were first reported in the state in the 1960s in Hialeah, Coral Gables and Key Biscayne, according to the Florida Fish and Wildlife Conservation Commission website.
The iguana has now been found in 33 counties stretching all the way up the Atlantic Coast into Georgia and along the Gulf Coast. Some have even been sighted in the panhandle region.
Colato and co-founder Blake Wilkins started the business about a year ago because the problem has become so significant.
Redline gets between 75 and 100 calls for service weekly, Colato said.
Steve Johnson, a UF associate professor of wildlife ecology and conservation, said the Cuban tree frog is another example of an invasive species in Florida whose spread may be “exacerbated” by climate change.
Cuban tree frogs are believed to have arrived in the Sunshine State in the 1920s as stowaways in shipping containers, Johnson said. The state’s heat, humidity and year-long temperate weather kept their populations steady.
“It makes Florida sort of an ideal place for them,” he said. “They’re established throughout the state.”
Much like the green iguana’s takeover, Cuban tree frogs may have been impacted by climate change through decreased frequencies of cold temperatures.
They eat native tree frog species and take over environments, Johnson said. Although they are not poisonous to dogs like the cane toad, also known as the bufo toad, they cause headaches for people, too.
Some have even short-circuited air conditioning units, Johnson said.
Although non-native species have already been well-documented throughout the state, he said, people can make a difference by reporting new finds to authorities such as Florida Fish and Wildlife.
“If everyone did that, it would make a difference,” he said.
New techniques have enabled researchers to make progress in tracking one of the most notorious invasive species in Florida, the Burmese python.
Margaret Hunter, a research geneticist at USGS Wetland and Aquatic Research Center in Gainesville, uses Environmental DNA by collecting water samples and extracting the python’s genetic information, to track the elusive snakes, which have not yet been able to be stopped from spreading.
The technique isn’t foolproof for determining exactly how many are in a given location, she said, but helps track overall trends.
“That is obviously very difficult given the size of the Everglades and how difficult they are to detect,” she said.
Burmese pythons camouflage well in the swamp areas where they are mostly found.
When it came to the 2010 cold snap, the Burmese python reacted differently from the green iguana and Cubn tree frog, Hunter said.
“It appears they might have the ability to adapt to colder temperatures,” she said.
Hunter said her team has not specifically studied whether climate change has impacted the Burmese python’s expanded range, but that her research area has spread beyond just the Everglades since starting in 2014.
She said it would be difficult to completely stop the breeding of escaped or released invasive pythons in Florida, but that tracking them can help people as their ranges expand.
“It can help managers learn how to prepare when they move into an area,” Hunter said.
David Zierden, the state climatologist and an associate researcher at Florida State University’s Center for Ocean-Atmospheric Prediction Studies, said weather patterns impacted by climate change include rising overnight temperatures and greater amounts of rainfall.
He said current research does not directly link extreme weather patterns to climate change in the state, but it is a definite possibility as temperatures and rainfall increase.
“It’s been a combination of causes,” Zierden said.
As temperatures increase, he said plant and animal species such as the snail kite or green iguana may continue moving north.
However, he stressed the importance of considering other impacts on animal movement, such as pollution and nutrient runoff.
“Our changing climate is only one stressor on our plants and animals here in the state,” he said. “We need to take a holistic approach.”
Florida Fish and Wildlife recently launched a website, www.climateadaptationexplorer.org, which details the impacts of climate change on species and environments, as well as potential solutions.
Scheffers, the study's author, said species movement caused by climate change is an issue that crosses geopolitical boundaries.
Scientists and policymakers from multiple states and nations will need to work together to create solutions, he said.