Key deer, the smallest subspecies of white-tailed deer in North America, are emblematic of the Florida Keys. The endearing creatures are miniature versions of their larger counterparts, captivating onlookers with their tiny stature and friendly demeanor.
According to the Florida Fish and Wildlife Conservation Commission, the Key deer were once poached almost to extinction and in 1967 were put on the endangered species list, where they remain today. Although the population has somewhat stabilized, with an estimated 700 to 800 individuals currently thriving in the Lower Keys, the threat of extinction continues to haunt these delicate creatures.
Since its inception in 2017, Save Our Key Deer (SOKD) has been a prominent force in the ongoing battle to safeguard and preserve the iconic Key deer. SOKD has funded crucial research undertaken by local scientists, highlighting the details of the Key deer’s fragile habitat.
A recent peer-reviewed article published in the Journal for Nature Conservation has revealed a disturbing trend: The deer are becoming increasingly domesticated due to a critical shortage of clean drinking water. This development, coupled with other threats such as the encroachment of rising sea levels, the effect of hurricanes and the unpredictability of seasons, continues to endanger the species’ existence.
SOKD embarked on a multiyear investigation to determine the severity of freshwater scarcity affecting the vulnerable Key deer population. The comprehensive study examined 89 freshwater holes, spanning the archipelago from the southernmost reaches of Sugarloaf Key to the northernmost shores of Big Pine Key.

The project yielded valuable insights, SOKD president Valerie Preziosi said, shedding light on the challenges confronting the Key deer and providing crucial information for guiding future management strategies and enhancing their prospects for long-term survival.
In an island chain surrounded by salt water, deer have been observed actively drinking from water sources with a salinity of up to nine parts per thousand (seawater, meanwhile, is roughly 35 parts per thousand). Still, like most animals, they do need a certain amount of fresh water to survive.
“Our research shows that the Key deer require lower-salinity water sources than previously believed,” explains Preziosi. “We hope this new information compels the (National Key Deer Refuge) to enhance as many individual water holes as possible, resulting in the deer returning to the woods where they belong.”
Human development has accelerated a rampant loss of critical habitat and vital sources of clean drinking water. Historically, the remarkable survival of these deer hinged on the unique geological features of the Keys, which provide surface access to underground freshwater reserves. These natural water features served as lifelines for the deer, offering unlimited access to critical hydration. However, the march of human development has decimated many of these invaluable sites, leaving the delicate balance of the Key deer’s ecosystem teetering on the brink.
In recent years, a troubling trend has unfolded, as Key deer are displaying increasingly tame behaviors. The unsettling shift stems from their dependence on human intervention. The scarcity of natural water sources has left some deer heavily reliant on the efforts of humans, who provide fresh water in makeshift receptacles such as buckets, bird baths, manmade backyard ponds and pet bowls.
This reliance on human charity represents a dramatic departure from the wild instincts of these creatures, raising concerns about their long-term viability and the fragile equilibrium of their delicate ecosystem.

The readily-available drinking water appears to be a prime resource sought out by the deer that regularly visit residents’ properties. While it is illegal to feed or touch Key deer, it is not illegal to leave water out for them. Local neighbors may leave clean water for deer to drink, as the animals face a historically low availability of natural drinking water in their native habitats – but Preziosi said SOKD believes the ultimate goal is to return the deer to enhanced water sources in the woods.
“Our current journal publication is essential research to consider when the U.S. Fish and Wildlife (Service) updates its mandatory species status assessment for the endangered Key deer,” said Preziosi. “Delisting the species from its endangered status will be extremely difficult. … We hope our research encourages the refuge to reimplement enhancements of appropriate individual water sources.”
If you see an ill or injured Key deer, contact FWC’s Wildlife Hotline at 888-404-3922, ext. 1. More information is at www.saveourkeydeer.org.
Photos by VALERIE PREZIOSI/Contributed