Updated on September 7, 2026. Key deer (Odocoileus virginianus clavium) are the smallest North American white-tailed deer, endemic to the Lower Florida Keys. Adults stand 25–30 inches at the shoulder. They remain federally endangered. Taking any deer in the Keys is illegal.
This is the subspecies profile. The parent encyclopedia is deer species. The mainland animal is white-tailed deer. The other tiny hunted whitetail we cover is Coues deer — Arizona and Mexico, not Florida. Mainland Florida hunting lives on Florida deer hunting. Key deer are not a hunt.
Key deer facts (sourced)
| Scientific name | Odocoileus virginianus clavium (Barbour and Allen, 1922). ITIS TSN 202409. A subspecies of white-tailed deer, not a separate species. ITIS; U.S. Fish and Wildlife Service, Key deer |
|---|---|
| Size | Adults 25–30 in at the shoulder. Bucks average 55–75 lb; does 45–65 lb. Stockier body, shorter legs, and a relatively wider skull than mainland whitetails. Fawns about 1.5 kg (3.3 lb) at birth. FWS species profile; Hardin et al. 1984, cited in FWS hurricane BMP |
| Range | About 25–26 islands from Big Pine Key to Sugarloaf Key, Monroe County, Florida. About 75% of the animals live on Big Pine and No Name Keys. Historic range ran from Vaca Key to Key West. Boca Chica sightings are treated as temporary visits. FWS; National Key Deer Refuge |
| Population | A few dozen animals in the 1950s. About 1,000 in 2016. New World screwworm (2016–17) and Hurricane Irma (Sept. 2017) cut the count. 2020 surveys about 750. FWS stated in 2023 that 2022–23 studies indicated a return toward pre-screwworm and pre-Irma levels. No 2026 census is published here. FWS recovery-plan FAQ, 2022; FWS, July 2023 |
| Conservation | Federally endangered since March 11, 1967 (Endangered Species Preservation Act; continued under the ESA of 1973). NatureServe G5T1 / Florida S1. The species O. virginianus is IUCN Least Concern; this island race is not. Still listed; a 2022 recovery-plan amendment added delisting criteria and did not change status. NatureServe; IUCN O. virginianus |
| Habitat | Pine rockland and tropical hardwood hammock for year-round needs; also mangrove, freshwater wetland, and neighborhoods. Fresh water is the limiter. FWS |
| Diet | More than 160 plant species. Primary items include red mangrove, blackbead, grasses, pineland acacia, Indian mulberry, and pencil flower. Menu shifts with season. FWS |
| Reproduction | Rut begins in September, peaks in October, declines through December–January. Gestation about 204 days. Fawning peaks April–May with the rainy season; spotted fawns have been seen in every month. Twins are uncommon; triplets have not been documented. FWS; Folk and Klimstra 1991 via NatureServe |
| Life span | Does average 6.5 years (maximum observed 19). Bucks average 2.9 years (maximum observed 12). Male annual survival is lower. FWS |
| Hunting | None. FWC: taking deer is prohibited by any method in the Florida Keys. Feeding is illegal. Report injured, sick, or dead animals to the FWC Wildlife Hotline, 888-404-3922, option 1. FWC taking game; FWS refuge |
| Official pages | FWS Key deer · National Key Deer Refuge · FWC taking game |
| Last checked | September 7, 2026 |
Those rows wear a source. Weights and island counts are not a single “average deer.” If this table and the FWS species page disagree, FWS wins.
How to tell a Key deer from a mainland whitetail, a Coues, and a fawn
Geography does most of the work. If the animal is on Big Pine Key, No Name Key, or a neighboring Lower Keys island, it is a Key deer. Mainland Florida still holds ordinary white-tailed deer. Those animals live north of the Keys chain. FWC closed the Keys to taking any deer, which is why the Florida deer hunting page treats this subspecies as a photograph, not a tag.
Size is the field mark once you are off the Overseas Highway. FWS puts adults at 25–30 inches at the shoulder. A typical mainland Florida buck is taller at the shoulder than a Key deer is at the ear. Northern farm-country bucks on how much a deer weighs run 150–300 lb. A Key deer buck is 55–75 lb. The body is stockier, the legs shorter, the skull relatively wider. That is island dwarfism, not a stunted yearling.
A spotted Key deer in May is a fawn, not a different species. Spots drop on the same schedule as other whitetails — see when fawns lose their spots. An unspotted adult that looks “too small” is still an adult. Do not call it a baby because a Michigan buck would stand over it.
The other tiny North American whitetail is the Coues deer of Arizona, New Mexico, and Mexico. Coues bucks rarely top 100 lb and live in desert mountains, not mangroves. The hunt mix-up is Coues deer vs mule deer. You will not see a Coues in Monroe County. You will not see a Key deer on the Mogollon Rim.
The world’s smallest living deer is not this animal. That is the southern pudu of the Andes, a different genus. Key deer are still Odocoileus: they flag a white tail, grow typical whitetail antlers on bucks, and bound. They are a small whitetail, not a pudu with a Florida zip code.
Spotted exotic deer on Texas ranches are a different problem. Axis vs whitetail and sika vs whitetail cover those. Axis and sika keep spots as adults. Adult Key deer do not. Mule deer vs whitetail is the western native split; mule deer do not live in the Keys.
Range: 26 islands, not “the Florida Keys”
FWS currently maps Key deer on about 25–26 islands from Big Pine Key west and south to Sugarloaf Key. The 2023 Service story puts the historic range from Vaca Key to Key West. Development, hunting, and habitat loss pinched that map. Boca Chica, near Key West Naval Air Station, is outside the official range; deer seen there are treated as wanderers from Sugarloaf.
About 75% of the population lives on two islands: Big Pine Key and No Name Key. That is why a visitor who only drives U.S. 1 to Key West can miss them, and why a resident of Big Pine cannot. Density plus roads is the collision problem. The National Key Deer Refuge, established in 1957, was created to hold the last animals. FWS’s 2022 recovery FAQ called it a 9,000-acre refuge; a Keys refuges complex sheet also lists a much larger acreage that includes marine waters. Use the refuge page for the current map. The Nature Center is at 30587 Overseas Highway on Big Pine Key. Hours move; confirm before you go.
They swim. FWS: Key deer walk, wade, or swim from island to island. That is ordinary deer behavior on a map made of water, not a unique superpower — can deer swim is the family page. In the dry season they pull onto larger islands with reliable fresh water. Pine rockland solution holes and constructed wetlands matter more than a beach photo.
This is not a second Seneca white deer story. Seneca whites are a fenced color morph of mainland whitetail. Key deer are a named subspecies that evolved on islands. The Latin clavium is “of the keys.”
Diet by season
FWS lists more than 160 plant species. That is a Keys menu, not a Midwest browse list. Primary items on the Service species page: red mangrove, blackbead, grasses, pineland acacia, Indian mulberry (Morinda), and pencil flower. Older summaries add black mangrove, silver palm fruit, and thatch palm berries. The mix shifts with the wet and dry seasons and with what a lactating doe needs in spring.
They are herbivores. They are not “the deer that eat mangrove bark and nothing else.” Red mangrove is a staple, not the whole diet. Hardwood hammock fruits, pineland forbs, and lawn edges all get used. That is why a Big Pine garden looks like a salad bar. The family diet page is what deer eat; mainland browse is what a white-tailed deer eats. Hostas are a northern shade-garden problem, not a Keys plant — that question lives on do deer eat hostas. Keys damage is tropical ornamentals, fruit trees, and anything watered in the dry season. Neighborhood conflict is the same pest pattern as deer as pests, on a much smaller animal.
They need fresh water. FWS and the Florida Natural Areas Inventory both treat upland communities as the year-round habitat because that is where drinkable water sits. They can take mildly brackish water. They cannot live on seawater. After Hurricane Irma’s storm surge salted wetlands in 2017, FWS put out emergency water stations — a one-time break from the usual “do not feed or water” line, because the natural holes were undrinkable.
Do not feed them. Handouts pull deer to roads, concentrate animals, and spread parasites. FWS and FWC both say feeding is illegal. Bread, fruit, and “just a carrot” are not a kindness. The backyard-feeding page is what to feed deer in your backyard — the answer there is still do not.
Reproduction and fawns
A female is a doe. A male is a buck. A baby is a fawn. Key deer keep those names because they are whitetails.
FWS: breeding starts in September, peaks in October, and declines through December and January. Younger animals breed later, if they breed. Male and female fawns are not reproductively active. Most yearling bucks do not breed. Many yearling does do. Adult bucks can be shut out by older, more aggressive males. That is a small-island rut, not a 40-acre Midwest bachelor group. Timing of the family rut is on when is deer mating season and the deer rut explained.
NatureServe, citing Folk and Klimstra 1991: gestation lasts 204 days; a single fawn is the rule; twins are uncommon. USDA Forest Service notes for southern whitetails: triplets have not been documented in Key deer. Fawning peaks in April and May, which is the Keys rainy season — FWS’s point is that lactating does then have green forage. Spotted fawns have been recorded in every month. Does bed fawns in open hammock and pineland, then leave them to feed. If you find a spotted fawn alone, leave it. The doe knows where it is. How many fawns a mainland doe carries is a different page: how many fawns do deer have.
Antler cycle
Only bucks grow antlers. FNAI: males more than two years old carry them. FWS’s refuge calendar is the working Keys clock: antlers in velvet in July and August; velvet scraped and antlers used in sparring as the September–October rut starts. They shed after the breeding season and grow a new set in spring, the same annual cycle as other deer — why deer shed their antlers and do deer antlers grow back. Racks are typical whitetail beams with upright tines, scaled to a 60-pound animal. They are not palmate, not axis lyres, and not a Coues desert 10-point.
The 2016–17 screwworm outbreak showed why the rut is also a wound season. USDA and UF/IFAS: New World screwworm (Cochliomyia hominivorax) killed or forced the euthanasia of about 135 Key deer, roughly 9–20% of the herd, with about 82% of those deaths in males. Flies laid eggs in sparring cuts. That is an antler-cycle mortality, not a random plague. Sterile-fly release and treatment ended the outbreak; USDA declared it eradicated in 2017. It was the first U.S. infestation in decades.
Predators — and the thing that actually kills them
The refuge page is blunt: despite the absence of large native predators, Key deer still flag the tail when alarmed. There is no panther in the Lower Keys. There is no wolf. Free-roaming dogs and the occasional alligator at places like Blue Hole can take a fawn; they are not the population driver. The family predator page is what eats deer.
Cars are. A 2022 analysis of refuge mortality records from 1966–2017 found that about 75% of reported Key deer deaths were vehicle collisions. U.S. 1 bisects Big Pine Key. FDOT and FWS have fenced roughly three miles of that highway, with two underpasses and four deer guards (cattle-grate style) to keep deer off the pavement. Posted speeds on the mitigated stretch have been 45 mph by day and 35 mph at night. Collisions still happen on unfenced local roads and on the unmitigated highway sections. If you hit a deer anywhere else in the country, start at what to do if you hit a deer. In the Keys, call 888-404-3922, option 1. Do not load a Key deer into a truck. It is a listed animal.
People, the refuge, and why they are still listed
Unregulated hunting and habitat loss dropped the herd to a few dozen animals by the 1950s — FWS has used “about 25” in recovery materials. Florida banned hunting them in 1939; poaching continued. The refuge dates to 1957. Federal listing followed on March 11, 1967, the same early endangered list as the Florida panther and the Florida manatee. The population recovered into the hundreds, then to about 1,000 by 2016, then took the screwworm and Irma hits. FWS is not currently delisting. The 2022 recovery-plan amendment added quantitative delisting criteria, including sea-level-rise habitat, connected subpopulations on Big Pine, No Name, Sugarloaf, and Cudjoe, and managed vehicle and disease mortality. An amendment is guidance. Status changes only through the Federal Register.
Sea-level rise is the long threat the 1999 plan did not quantify. Pine rockland and freshwater holes sit a few feet above the water. If those uplands drown, the subspecies has nowhere else on Earth to go. Short-term threats are still cars, illegal feeding, development on private inholdings, hurricanes, and disease in a small gene pool.
They are wild animals that live in a wildland–urban interface. FWS, July 2023: they are not domesticated, not semi-wild, and not a petting-zoo herd. They will walk a neighborhood because people live inside the range. That is not an invitation to touch them. Photograph from a car or a trail. Blue Hole (an old quarry), the Jack Watson Wildlife Trail, and the Fred Mannillo Wildlife Trail are the named public walks on the refuge. Stay in the car if a deer is in the road. Wait. Do not honk it into traffic.
Mainland Florida still has a deer season. The Keys do not. If you came here looking for a south-Florida hunt, turn around to Florida deer hunting and hunt Zone A or the panhandle. Do not invent a Key deer tag.
FAQ
Are Key deer a separate species? No. They are a subspecies of white-tailed deer, Odocoileus virginianus clavium. Same genus, same tail flag, same antler plan. The size, skull, and island range are what the name marks. Full species context: white-tailed deer and the deer species hub.
Can you hunt Key deer? No. FWC prohibits taking deer by any method in the Florida Keys. They have been federally endangered since 1967. There is no tag, no leftover, and no “oops, I thought it was a mainland deer” defense on Big Pine Key.
How many Key deer are left? FWS put the 2016 high near 1,000, the 2020 survey near 750 after screwworm and Irma, and said in 2023 that newer studies pointed back toward pre-2016 levels. Treat “about 800” as a working band, not a 2026 census. Confirm on the FWS species page.
Why are they so small? Island dwarfism. Limited forage, isolation from mainland herds, and thousands of years on a small landmass selected for a smaller body. They are not starving mainland deer. A healthy Key deer buck at 70 lb is a large Key deer, not a small Illinois deer.
Is it legal to feed them? No. FWS and FWC both say do not feed, approach, or touch Key deer. Feeding pulls them to roads and spreads disease. A backyard feeder is how a listed animal learns to stand in U.S. 1.
Where can I see them? Dawn and dusk on Big Pine Key, often south toward Lower Sugarloaf. Start at the National Key Deer Refuge Nature Center on Overseas Highway, then the named trails. Drive the posted speed. If you hit one, or find one injured, call 888-404-3922, option 1. Collision how-to for the rest of the country: what to do if you hit a deer.
Sources
- U.S. Fish and Wildlife Service. Key deer species profile. Size, diet, range, reproduction, life span. fws.gov/species/key-deer-odocoileus-virginianus-clavium. Last checked September 7, 2026.
- U.S. Fish and Wildlife Service. National Key Deer Refuge. Listing history, 75% of the herd on Big Pine and No Name, no large predators, feeding, visitor sites. fws.gov/refuge/national-key-deer.
- U.S. Fish and Wildlife Service. Key deer recovery plan amendment FAQ, July 12, 2022. Population 2016 / 2020, delisting criteria, sea-level rise, highway fencing. fws.gov/story/2022-07/key-deer-recovery-plan-amendment.
- U.S. Fish and Wildlife Service. “Key Deer: Wild Animals in a Wildland-Urban Interface,” July 10, 2023. Historic range, 2022–23 population note, hotline. fws.gov/story/2023-07/key-deer-wild-animals-wildland-urban-interface.
- Florida Fish and Wildlife Conservation Commission. Taking game: “Taking deer is prohibited by any method in the Florida Keys.” myfwc.com/hunting/regulations/taking-game.
- NatureServe Explorer. Odocoileus virginianus clavium. G5T1 / S1; Endangered March 11, 1967; Folk and Klimstra 1991 reproduction notes. NatureServe taxon page.
- Florida Natural Areas Inventory. Key deer field guide (2000). Shoulder height, weights, hammock and pineland use. FNAI PDF.
- Hardin, J.W., Silvy, N.J., and Klimstra, W.D. 1984, as cited in FWS Key deer hurricane-response BMP: adult male 36 kg, adult female 28 kg, fawns ~1.5 kg; shoulder height 69 cm bucks / 65 cm does. FWS BMP PDF.
- Parker, I.D. et al. and UF/IFAS EENY-668. New World screwworm in Key deer, 2016–17: about 135 deaths, male-biased, sterile-fly eradication. UF/IFAS screwworm.
- Begley, J.S. et al. 2022. Nature Conservation 47: 283–302. About 75% of reported Key deer mortality 1966–2017 from vehicles; U.S. 1 fence and underpasses.
- Silvy, N.J. et al. 2022. Wildlife Society Bulletin. March 2020 mark-resight estimate n = 748 on Big Pine and No Name Keys.
- Gallina, S. and López-Arévalo, H. 2016. Odocoileus virginianus. IUCN Red List, Least Concern. IUCN.
- ITIS. TSN 202409, Odocoileus virginianus clavium Barbour and Allen, 1922. ITIS record.
Parent hub: deer species. Siblings: white-tailed deer, Coues deer, southern pudu, endangered deer species. Florida hunt (mainland only): Florida deer hunting.
