STATUS: Endangered throughout its range, Federal Register, March 11, 1967
DESCRIPTION: This is the smallest race of North American deer. Adults measure 25 to 30 inches at the shoulder and have an average weight of 55 to 75 pounds for males and 45-65 pounds for females. The body is stockier, legs shorter, and skull wider than other races of white-tailed deer. The coat varies from a deep reddish brown to a grizzled, gray color. Bucks usually have antlers by their second year, and eight points by the fifth.The Key deer's primary food source is the red mangrove (Rhizophora mangle), but approximately 60 other plants are also known to form part of its diet. Possibly most of the available plant species are used at one time or another. The selection of some food plants changes seasonally, probably reflecting availability and nutritional needs. Other plants are browsed almost continuously resulting in their stunting and near extirpation.
REPRODUCTION AND DEVELOPMENT: Breeding occurs all year but peaks in September and October. Territorial activity seems limited to defending a receptive doe from other bucks. Bucks with full racks are generally the earliest breeders and exclude yearling males and those with lesser racks. The peak of fawning coincides with the rainy season in April and May. Key deer have a relatively low reproductive rate, averaging 1.08 fawns per adult doe annually. Male fawns outnumber females, but the sex ratio changes until adult females outnumber males 2.38 to 1. Longevity records are 8 years for males and 17 years for females. Adult females form loose matriarchal groups with one or two generations of offspring, while bucks feed and bed together during the non-breeding season only.
RANGE AND POPULATION LEVEL: Key deer are restricted to Monroe County, Florida, and are permanent residents in the following Lower Keys: Big Pine, Big Torch, Cudjoe, Howe, Little Pine, Little Torch, Middle Torch, No Name, Sugarloaf, and Summerland. The following Lower Keys receive transient use only because of their lack of a permanent supply of fresh water: Annette, Big Munson, Little Munson, Johnson, Knockemdown, Mayo, Porpoise, Ramrod, Toptree Hammock, Wahoo, Water Key (east) and Water Keys (west). The current Key deer population is an estimated 250 to 300 animals. In 1955, the number of Key deer was estimated at 25 to 80.
HABITAT: Only islands with permanent fresh water are used consistently by Key deer. Big Pine Key (5,997 acres) and No Name Key (998 acres) support more than two-thirds of the population. Both have permanent fresh water and extensive pineland habitat. One study indicates that habitat use is in the following order of preference: pinelands, hardwood hammocks, buttonwood-scrub mangrove, mangrove swamp, and developed areas. Habitat selection varies with season, time of day, and the sex and age to the animal. Pinelands, hardwood hammocks, recent clearings, roadsides and grassy areas are used for feeding. Burned-over pinelands produce new growth which is browsed extensively for 6 months or more. Hammocks and mangrove swamps are used for cool retreats during the day. Home ranges average about 299 acres (greater during the breeding season) for males, and about 138 acres for females.
REASONS FOR CURRENT STATUS: The greatest current impact on Key deer is the loss of habitat to development. Anticipated future population growth implies a further loss of habitat. Other current factors include road kills, mortality of young from falling into drainage ditches, and killing by free-roaming dogs. Overhunting with dogs and jacklights was probably an important factor in the 1940's and 1950's.
MANAGEMENT AND PROTECTION: Recommendations for management include: continuation of a closed hunting season; acquisition of additional refuge habitat on Big Pine, No Name, and Cudjoe Keys; prescribed burning in pinelands habitat; maintenance of existing water holes; management of vegetation along selected roadways; providing underpasses to allow deer to cross safely under U.S. Highway 1; elimination of public feeding; population and habitat monitoring; visitor management; and additional research on all aspects of Key deer biology. Other recommendations include: strict enforcement of speed limits on Big Pine Key; reduce speed limits along U.S. Highway 1 to 35 miles per hour on Big Pine Key; and rigorously control free-roaming dogs.