Florida’s Endangered Key Deer Survived Hurricane Irma—but Their Future Is Stormy

From climate change to kidnappings, the threats are adding up against these tiny, adorable cervids.

Murray Foubister/Flickr

Way down in the Florida Keys live about 950 miniature relatives of the white-tailed deer. Since the last Ice Age 11,000 years ago, the species has become so adapted to island living that it has shrunk down to no more than 32 inches tall, about the height of a toddler. So when Hurricane Irma struck Florida in September, it’s no surprise that people were worried that the six-foot storm surge might sweep the tiny deer into the sea of extinction.

But these little guys are tougher than they look. In the two months since the storm, wildlife managers at the National Key Deer Refuge have determined that nearly all of the endangered Key deer survived. Just 21 of them died from storm-related causes, says Kristie Killam, a ranger for the Florida Keys National Wildlife Refuges, a group of four refuges spread among the islands.

How did a 60-pound animal not even three feet tall stand up against six feet of seawater surge? Killam says nobody really knows. The Keys were evacuated, and those residents who chose to stay obviously weren’t focused on observing wildlife behavior. What Killam does know is that these deer routinely swim between the islands, so they are no strangers to water. And because Irma wasn’t the first hurricane to swirl over the Florida Keys in the thousands of years the deer have lived there, they’ve likely become experts at riding out a storm.

Unfortunately, there are other threats these deer aren’t so good at dodging. Like Hyundai Sonatas.

Vehicle strikes represent an ever-present threat to Key deer (and other animals), but cars come with other dangers―namely, people. Last July, a Monroe County Sherriff’s deputy pulled over two men in a Sonata for a traffic violation and soon discovered they were not the only passengers. The men had kidnapped two live Key deer, hog-tied them, and stuffed them into the Sonata’s back seat. On further inspection, the deputy found a third deer, a fully antlered buck, hidden in the trunk.

According to Killam, this is just one of many bad things that can happen when deer become habituated to humans. Whether it’s through dining on our trash and our gardens or receiving handouts from well-meaning residents, many Key deer have lost their fear of people. And when that happens, they can become more likely to be attacked by dogs, mowed down by cars, or picked up by a couple of weird dudes.

Vehicle strikes are an ever-present threat to Key deer

Florida Fish and Wildlife/Flickr

But this is no laughing matter. The buck in the trunk broke one of its legs trying to escape and had to be euthanized. And touching, harassing, or possessing a federally protected species is a federal offense. In October, the duo’s ringleader was sentenced to a year in federal prison, while his accomplice got off with a year of supervised release. The two said they had just wanted to “take pictures” with the deer. Right.

Killam says that while that particular situation was extreme, unfortunate human–deer incidents happen all the time. For those who like to feed the animals, Killam suggests planting native vegetation and creating wild habitat around their houses. “[It’s] a way to feed wildlife without feeding wildlife,” she says.

Another threat that humans can help mitigate is a kind of flesh-eating parasite called the New World screwworm. These flies and their maggots usually munch on cattle and other livestock. The adults lay their eggs on or near an animal’s skin wounds, and when the maggots hatch, they have rings of spikes all over their bodies, the better for burrowing into flesh. One tiny screwworm is a painful inconvenience, but dozens or even hundreds of the buggers can actually kill—which is what they did to at least 135 Key deer beginning in the summer of 2016.

No one is really sure where these screwworms came from last year, especially since the last reported case of infection anywhere in the United States was more than 30 years ago. Back then, the screwworm cost the livestock industry some $20 million a year, so the U.S. Department of Agriculture sterilized and released billions of adult flies in order to stop the reproduction cycle. Eventually the screwworm population collapsed.

When the parasites popped up in the Keys, wildlife refuge staff, the U.S. Fish and Wildlife Service, the USDA, and dozens of local volunteers banded together to inoculate every deer they could get their hands on. They also released 40 million sterile adults. (If it ain’t broke, don’t fix it.) Thankfully, the plan worked, and this spring the herd was given a clean bill of health.

Screwworms, hurricanes, and kidnappers, however, take a back seat to the Key deer’s biggest existential threat: climate change.

The deer play musical chairs between a number of islands in the lower Keys, but they chiefly live on Big Pine Key and No Name Key—both of which, on average, lie only about three feet above sea level. According to some estimates, all of the Florida Keys could experience as much as 15 inches of sea-level rise by 2045. At the same time, other research shows that the ocean floor around the Keys is eroding away at higher than normal rates, likely a result of ailing coral reefs. And because reefs provide protection against waves and storm surges, the islands will be more vulnerable to hurricanes in the future. In short, the Keys are getting it from both ends.

Add it all up, says Killam, and you have a threat not just to Key deer but to the very habitats that sustain them—and more than a dozen other federally protected species, such as the Lower Keys marsh rabbit (endangered), Bartram’s hairstreak butterfly (endangered), and the Miami blue butterfly (endangered).

These species are all survivors, but their world is changing rapidly—perhaps too rapidly for them to adapt this time. 


onEarth provides reporting and analysis about environmental science, policy, and culture. All opinions expressed are those of the authors and do not necessarily reflect the policies or positions of NRDC. Learn more or follow us on Facebook and Twitter.

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