Share this article
Wildlife Featured in this article
- Key deer
Wild Cam: Lack of water drives key deer toward domestication
Wildlife managers may need to create artificial water sources to avoid extirpation in some areas
A lack of natural water sources as a result of climate change may be driving an endangered subspecies of white-tailed deer found only in the Florida Keys toward domestication.
If wildlife managers don’t stop residents from providing water to deer—and if they fail to expand artificial water sources—the Key deer (Odocoileus virginianus clavium) could become extirpated from their only natural habitat in the Florida Keys.
“It’s important to characterize the true state of affairs as far as the state of domestication,” said Jan Svejkovsky, president of the Ocean Imaging Corporation, a consulting business that conducts various types of environmental projects.

Key deer, the smallest deer species native to North America, primarily feed on red mangroves that grow in the Keys. The U.S. Fish and Wildlife Service considers the ungulates endangered due to the loss of habitat from development, domestication from humans feeding them, and changes to the fire regime in the area.
Svejkovsky has been interested in conserving these deer since just after Hurricane Irma struck southern Florida in September 2017. He and his wife, Valerie Preziosi, started a nonprofit called Save Our Key Deer, Inc., after hearing that wildlife rehabilitation centers in the area didn’t focus on this species.

How do Key deer find water?
In examining the ecology of the species, Svejkovsky and other volunteers with the foundation quickly realized that one of the main obstacles for recovery may be the availability of natural drinking water.
Decades earlier, a graduate student had mapped 294 watering holes in the Keys. But a closer examination revealed that many of these either dried up for most of the year, like the one pictured above, or became too salty to drink from. Further, hurricanes like Irma can lead to storm surge and sea level rise that can increase the salinity of freshwater sources.
In a study published in the Journal for Nature Conservation, Svejkovsky and his colleagues took a closer look at these water sources to determine how deer were subsisting in the Keys.

The team began their research by testing and monitoring about 80 drinking holes from those originally mapped in the 1990s and found that many of them dried up for at least part of the year. Only a fraction of them served as year-round water sources, which came from either rainwater or underground freshwater lenses. The latter occurs when rainwater seeps through porous rock and forms a convex-shaped layer of fresh groundwater that floats above the denser saltwater below.

The holes filled with rainwater in particular—like the one pictured above—often dry up or become more saline in the less rainy seasons.
Overall, the team’s surveys revealed that large parts of Key deer habitat lacked natural drinking water sources. But since there were still deer in many of these areas, the researchers wondered how they were surviving.
Do people feed Key deer?
Residents in the Keys sometimes illegally feed deer. In fact, in some areas, the deer have become so domesticated that they allow people to touch them or hand-feed them. In one case, a Florida man faced charges for luring deer into his house with food, according to a local news broadcast.

In other cases, deer have become urbanized but not quite domesticated, where they’re invited into someone’s home. They may live largely off of food and water resources that humans provide.
“Due to the scarcity of the water resources, it’s silly to pretend that these are wild animals that do their own thing in the wild,” Svejkovsky said.
In fact, deer may be subsisting solely on natural freshwater sources only on a few smaller islands where there aren’t many people.

Svejkovsky fears that climate change and the resulting sea level rise and storm surges, which can make freshwater sources saltier, will only make matters worse. As a result, instead of residents providing freshwater directly to deer, he thinks a program that was started in the mid-2000s and subsequently abandoned should be readopted.
Back then, wildlife authorities enhanced some natural ponds in the Keys by digging out accumulated mud, sand and debris and expanding them. “That, in itself, could probably take care of some of these areas that experience a complete lack of drinking water in some seasons,” Svejkovsky said.
If not, he fears that subspecies may become extirpated from some of the Keys and totally domesticated in others.
This photo essay is part of an occasional series from The Wildlife Society featuring photos and video images of wildlife taken with camera traps and other equipment. Check out other entries in the series here. If you’re working on an interesting camera trap research project or one that has a series of good photos you’d like to share, email Josh at jlearn@wildlife.org.
Header Image: Key deer are only found in the Florida Keys. Credit: Valerie Preziosi