Florida Key Deer
Florida Key Deer
Odocoileus virginianus clavium
|Listed||March 11, 1967|
|Description||Small, white-tailed deer; tawny in summer, blue-gray in winter.|
|Habitat||Subtropical keys; woods and meadows.|
|Reproduction||Single fawn per season.|
|Threats||Loss of habitat, road kills.|
The Key deer is the smallest subspecies of the Virginia white-tailed deer found in the United States. Adult sizes vary considerably. The average weight of an adult male is 80 lbs (36 kg) and of an adult female, 64 lbs (29 kg). Average shoulder heights range from 24-28 in (61-71 cm). The adult is white beneath and tawny above in summer, blue-gray in winter. Fawns display white spots on a reddish coat that persist for about three months. All animals have a conspicuous white tail. Antlers have erect un-branched tines arising from the main beam.
Key deer are more solitary than other white-tailed deer, which travel in family groups. In many cases, the solitary behavior has been adversely modified by public feeding, which attracts artificially large groups. Left to itself, the Key deer feeds on a wide variety of subtropical plants, including the red mangrove, black mangrove, Indian mulberry, silver palm, and thatch palm.
The reproductive cycle of the Key deer is similar to that of its mainland relatives. Breeding begins in September, peaks in early October, and gradually decreases through November. Gestation is 204 days, after which a single fawn is born. Most births occur between March and May, peaking in April. Key deer reach sexual maturity between three and five years of age. Familial bonds are not highly developed, and fawns have been observed to move with any passing female.
The Key deer uses different sub-habitats on the islands, depending on availability, activity, and time of day. Hardwood hammocks and mangroves are frequented during daylight hours as they provide cover, bedding, and resting areas. Open meadow or grasslands, especially those that are routinely mowed, are used primarily during the evening for feeding and some limited bedding. Buttonwood and pine forests are used equally at all times. Freshwater sources, which are scarce on the Florida Keys, also influence frequency of habitat use.
The ancestors of the Key deer migrated to the region of the Florida Keys from the mainland many thousands of years ago. When the last glaciers melted, water levels rose, fragmenting what was once a long, narrow peninsula into a series of small islands. Isolation from mainland populations and the confines of an island habitat influenced the development of the Key deer's special physical characteristics and behavior patterns.
The earliest mention of the Key deer is found in the memoirs of Spanish explorer D. E. Fontaneda, who was shipwrecked in the Florida Keys in 1575. At that time, Key deer were apparently abundant and used as food by both Native Americans and crews from passing ships. The deer probably ranged from Key West to Duck Key.
The Key deer was hunted ruthlessly to the brink of extinction. Florida state law banned hunting in 1939, but by the end of the Second World War only about 30 deer survived.
The National Key Deer Refuge was established in 1957, and the population slowly began to recover. About the same time, however, residential and resort development began a boom in the Keys that continues today. By 1978, the Key deer population had increased to about 400 animals, but available habitat had shrunk to a fraction of its former extent. The Key deer is now restricted to the lower Keys. Of the current population, estimated at less than 300 deer in 1989, about 200 are found on Big Pine Key and No Name Key. The rest are scattered from Saddlebunch to Spanish Harbor Bridge and associated islands.
The Florida Keys have long been a popular tourist and resort area. More recently, developers have cleared land to build homes for full-time residents. Between 1969 and 1973 nearly 124 acres (50 hectares) were cleared annually on Big Pine Key alone. In 1984, 310 housing units were approved to support nearly 800 new inhabitants. The human population now stands at about 5,000, but at current rates of development all private land will be built out within 20 years, and Big Pine Key could support an estimated 20,000 residents.
A by-product of increased settlement is the increase of road kills, which now account for more than 80% of Key deer mortality. An average of 45 road kills per year is thought to equal most, if not all, of the yearly production of fawns. Public feeding compounds the problems by reducing the deer's fear of vehicles. In 1982 legislation was passed prohibiting the feeding or placing of food to attract Key deer, and although public feeding has diminished, the animals' behavior may take generations to return to normal. Recently, Monroe County stepped up enforcement of speed limits, visibly slowing the flow of traffic along the major highways. As a result, the number of road kills appears to have leveled off.
Free-ranging dogs are probably the second greatest cause of deer mortality. Dogs both kill young deer and chase deer into traffic to be killed by vehicles. Another cause of death among the deer is drowning. There are about 100 mi (165 km) of steep-sided ditches on Big Pine Key that are deep enough to drown fawns. Wildlife refuge personnel have initiated a project to fill the most dangerous ditches.
Conservation and Recovery
Most habitat for the Key deer probably can never be recovered sufficiently to greatly increase the size of the population. The goal of recovery, therefore, is to arrest habitat decline to whatever extent possible and to manage public lands in the Keys to stabilize the population between 200 and 300 animals. Recovery actions include limited controlled burns and other techniques to create and maintain open meadows within the refuge to prevent deer from straying into residential areas.
The U. S. Fish and Wildlife Service is working to expand the National Key Deer Refuge as funds become available.
Regional Office of Endangered Species
U.S. Fish and Wildlife Service
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
Allen, R. P. 1952. "The Key Deer: A Challenge from the Past." Audubon 54:76-81.
Barbour, T., and G. M. Allen. 1922. "The White-Tailed Deer of Eastern United States." Journal of Mammalogy 3 (2):65-78.
Florida Department of Community Affairs. 1984."Status of Major Development Projects, Monroe County." Bureau of Land Management, Key West, Florida.
Hardin, J. W., et al. 1976. "Group Size and Composition of the Florida Key Deer." Journal of Wildlife Management 40 (3):454-463.
U.S. Fish and Wildlife Service. 1985. "Florida Key Deer Recovery Plan." U.S. Fish and Wildlife Service, Atlanta.