BIG PINE KEY, Fla. — The world's only Key deer, the smallest subspecies of the white-tailed deer, are found in piney and marshy wetlands bordered by the Atlantic Ocean and Gulf of Mexico on the Florida Keys.
For years, their biggest threat was being struck by vehicles speeding along U.S. Highway 1 or local roads.
But those waters surrounding the islands now pose the biggest long-term risk for this herd of about 800 deer as sea rise jeopardizes their sole habitat.
Key deer walk in a residential neighborhood Oct. 15 in Big Pine Key, Fla.
These charismatic diminutive deer have been listed as endangered for almost 60 years after their numbers dipped to about 50 from hunting and poaching long ago.
Yet they made a tremendous comeback, with a peak population of about 1,000 in the mid-2010s before a deadly parasite and Hurricane Irma took a heavy toll.
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However, experts and wildlife advocates say this conservation success story today is at risk of being undone by climate change. Sea level rise is already altering the landscape of Big Pine Key and at least 20 smaller islands the deer call home.
The bulk of the deer live on Big Pine Key, a marshy island 30 miles from Key West. They roam neighborhoods where about 4,500 people live, browsing on lush gardens and drinking water from buckets residents put out for them as natural freshwater supplies dwindle.
A bucket of drinking water is left along a road for Key deer Oct. 17 in Big Pine Key, Fla.
Key deer are far smaller than their North American counterparts, with the biggest bucks standing less than 3 feet tall at the shoulder and weighing around 75 pounds.
"They were always vulnerable," said Chris Bergh, the South Florida program manager for the Nature Conservancy, who oversees sea level rise projects and lives in Big Pine Key. "They're much more vulnerable now. And with the sea level rising and their habitat shrinking, they're becoming even more so."
A Key deer crosses a road Oct. 17 in Big Pine Key, Fla.
Highway deer deaths
On Big Pine Key, mom and pop bars and restaurants dot either side of bustling U.S. 1, along with gas stations and small motels. The main industry revolves around the water — charter boats, fishing, diving, vacation rentals.
To protect the deer from being hit by vehicles, signs tell motorists they're entering deer habitat. A 2-mile stretch of U.S. 1 is elevated and fenced, allowing deer to cross under the road.
And speed limits are strictly enforced, often frustrating tourists driving to Key West.
A road sign warns motorists not to speed in an area frequented by Key deer Oct. 16 in Big Pine Key, Fla.
Deer still are struck at an alarming rate. "The bottom line is that some 90 to 120 deer are known to be killed by vehicles each year," said Jan Svejkovsky, chief scientist for Save Our Key Deer.
Wildlife officials have worked hard get out the message: Don't feed Key deer. They fear deer will approach cars and go near roadways for handouts.
Even with the traffic deaths, the population has remained stable. But a larger threat looms.
Key deer walk along mangroves Oct. 15 in Big Pine Key, Fla.
Climate change impacts on deer
The National Oceanic and Atmospheric Administration projects that by 2100, seas will rise 1.5 feet to 7 feet in parts of the Florida Keys. The threat is greatest to low lying islands like Big Pine Key, where the highest point is only about 8 feet above sea level.
Sea rise will continue to shrink freshwater and food sources Key deer need to survive, experts say.
"So as the sea rises, that shrinks the amount of available freshwater, the amount of available, palatable vegetation, the places for bearing their young," said Bergh of the Nature Conservancy. "It puts them increasingly in conflict with people who are also occupying those higher grounds."
In addition to sea rise, climate change brings the threat of stronger hurricanes, with storm surges that can damage deer habitat and freshwater supplies.
Salt water intrusion also is responsible for killing many of the Florida slash pines that gave Big Pine Key its name. Mangroves are growing in their place in an ever-changing environment, choking deer habitat even more.
Habitat of the Key deer and developments are seen Oct. 15 in Big Pine Key, Fla.
Shrinking habitat drives deer to neighborhoods
Key deer on Big Pine Key move through neighborhoods, munching on gardens. Some people even have names for ones that frequent their yards.
"They are very gentle, very, very gentle," said Connie Ritchie, who sometimes sees about 30 deer a day. "And the longer you live here, the more you want to protect them. Big time. Protect them because they're so innocent."
"They have certain plants that they really love," Ritchie said, noting that the federal deer refuge here hosts events where it gives away native plants. "So they're trying to teach us to plant the plants that the deer won't eat."
Development on Big Pine Key began in the 1970s and 1980s "when entire swaths of land on islands that still held deer were developed into planned subdivisions, complete with saltwater canal networks to provide lot-buyers with direct water access," said Svejkovsky of Save Our Key Deer.
A Key deer walks in a residential neighborhood Oct. 15 in Big Pine Key, Fla.
While the key remains mostly rural with modest Florida bungalows and more palatial places, development has taken away some deer habitat.
"We have lots of people and the wildlife living in the same really concentrated area," said Katy Hosokawa, a park ranger at the National Key Deer Refuge, established in 1957 on 8,542 acres of Big Pine Key. "So the more houses that we build, or the less lands that we have protected, the less areas that they have that are safe."
The deer have adapted to the humans and move freely between wild spaces and the neighborhoods. "They roam, they spend their day grazing," Hosokawa said. "We don't have a really nutritionally dense soil, so they need to eat a lot of food to get what they need. But trust me, they're very good at it. If it's soft and tender, they will try to eat it."
Jan Svejkovsky, chief scientist for Save Our Key Deer, watches one of the animals Oct. 16 in front of his home in Big Pine Key, Fla.
Future of the deer
The future, while uncertain, looks grim.
Just six inches of sea rise, expected by 2030, would mean loss of 16% of the freshwater holes on Big Pine Key, said Nova Silvy, professor emeritus with Texas A&M University who has studied Key deer since 1968 and has lived here for several years.
By 2050, sea rise is expected to overtake about 84% of the 1,988 remaining acres of the preferred habitat on Big Pine Key — and "the deer will already be gone," Silvy said.
Key deer walk in a residential neighborhood Oct. 16 in Big Pine Key, Fla.
What happens if the deer can't survive in the Keys?
Bergh said he prefers to buy more time to keep the deer viable here. "And at some point, if that's no longer possible, I personally think zoos are the most responsible alternative," he said. "But that's a terrible alternative. Who wants that for a wild animal?"
In rare instances, scientists have been allowed to relocate endangered species threatened by climate change as a last resort. But Silvy said, "The problem is if you take them any other place with deer, they're going to interbreed and then you've lost the Key deer."
Massive die-off of Pacific Northwest trees linked to climate change
Christine Buhl, a forest health specialist for the Oregon Department of Forestry, uses an increment borer to core a dead western red cedar at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023. Iconic red cedars — known as the "Tree of Life' — and other tree species in the Pacific Northwest have been dying because of climate-induced drought, researchers say. Last year, Buhl and colleagues reported that red cedars were dying throughout the tree’s growing range not because of a fungus or insect attack, but due to the region’s “climate change-induced drought.”
Christine Buhl, a forest health specialist for the Oregon Department of Forestry, holds a tree core from a dead western red cedar, showing healthier rings toward the right of the sample and more drought-affected rings to the left, at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023. In recent years, at least 15 native Pacific Northwest tree species have experienced growth declines and die-offs, 10 of which have been linked to drought and warming temperatures, according to recent studies and reports.
Three dead western red cedars, center, at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023. Iconic red cedars — known as the "Tree of Life' — and other tree species in the Pacific Northwest have been dying because of climate-induced drought, researchers say. A term coined by researchers, “Firmageddon” refers to the more than 1,875 square-mile die-off of five fir species in Oregon, Washington and northern California.
Bark on a dead western red cedar at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023. Iconic red cedars — known as the "Tree of Life' — and other tree species in the Pacific Northwest have been dying because of climate-induced drought, researchers say. The die-off is likely to move uphill as temperatures warm in the coming decades, according to a study in the Journal of Forestry.
Christine Buhl, a forest health specialist for the Oregon Department of Forestry, uses an increment borer to core a western red cedar at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023.
Woodpecker nesting holes in a dead western red cedar tree at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023.
Property manager James Bailey looks at a dead Douglas fir among several dead western red cedars at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023. Firmageddon and Douglas fir die-offs have been linked to a combination of drought weakening trees and insect pests moving in for the kill.
Moss grows on the branches of a dead western red cedar at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023. Iconic red cedars — known as the "Tree of Life' — and other tree species in the Pacific Northwest have been dying because of climate-induced drought, researchers say.
An increment borer attaches to a vest worn by Christine Buhl, a forest health specialist for the Oregon Department of Forestry, after taking tree core samples at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023.
A section of a Douglas fir tree with the bark removed by scientists to examine insect damage that led to the tree's death following heat stress in the Willamette National Forest, Ore., Oct. 27, 2023. Firmageddon and Douglas fir die-offs have been linked to a combination of drought weakening trees and insect pests moving in for the kill.
Douglas fir trees that died as a result of insect damage following heat stress are visible in the Willamette National Forest, Ore., Oct. 27, 2023.
Sun shines on leaves on a big leaf maple tree in the Willamette National Forest, Ore., Oct. 27, 2023. In recent years, at least 15 native tree species in the region have experienced growth declines and die-offs, with 10 linked to drought and warming temperatures, according to recent studies and reports.
Dead needles hang on a western red cedar tree in the Willamette National Forest, Ore., Oct. 27, 2023. Iconic red cedars — known as the "Tree of Life' — and other tree species in the Pacific Northwest have been dying because of climate-induced drought, researchers say.
James Bailey, property manager, right, and Christine Buhl, a forest health specialist for the Oregon Department of Forestry, walk along a trail in the forest at Magness Memorial Tree Farm in Sherwood, Ore., Oct. 11, 2023. In recent years, at least 15 native tree species in the region have experienced growth declines and die-offs, with 10 linked to drought and warming temperatures, according to recent studies and reports. (AP Photo/Amanda Loman)
