Key DeerOdocoileus virginianus claviumWhere and when to see them

The Key deer is a small island subspecies of white-tailed deer restricted to the lower Florida Keys. Its compact size reflects a long history in a limited island environment, but it is not a separate deer species. Freshwater availability, habitat fragmentation and vehicle collisions strongly influence its survival. Protection has prevented its disappearance, yet a confident animal beside a road should not be mistaken for a population free from serious threats.

Size

61-81 cm at shoulder

Weight

20-34 kg

Lifespan

Not reliably established

Status

Assessment varies

Key deer browse and move through island vegetation, often becoming most active around dawn and dusk. They can swim between islands, although roads and development constrain many daily movements. Females commonly remain in small social groups, while adult males become more competitive during the rut. Animals accustomed to people may approach closely, but feeding changes natural behaviour and draws them toward traffic, dogs and other hazards around developed areas. Key deer are excellent swimmers and will readily cross channels between islands to forage or escape danger. They exhibit a distinct social structure where related females often form small family groups. Males are largely solitary outside of the rut, though young bucks may form bachelor groups.

• It is an island subspecies of white-tailed deer.
• Individuals can swim between islands.
• Males grow and shed antlers annually.
• Freshwater sources are a critical resource despite its coastal distribution.

Key deer are resident and can be observed year-round where access is permitted. November to April generally offers cooler walking weather and fewer biting insects. Daily timing matters more than a migration season, while storms, heat and freshwater conditions can alter local activity. The fawning season typically runs from April to June, when observers might spot young fawns with their mothers. The rut, or breeding season, generally occurs in September and October, leading to increased male activity and competition. During hot periods, deer may become more crepuscular, resting in shaded areas during the day.

They use a mosaic of pine rockland, hardwood hammock, mangrove margins and freshwater wetlands. Access to drinking water is especially important in this saline island landscape. Coastal habitat alone is insufficient if freshwater, shelter and safe movement routes are missing or fragmented. They require continuous freshwater access for drinking, often finding it in limestone depressions or artificial sources. Despite their name, Key deer do not inhabit every island in the Florida Keys, but are concentrated in the Big Pine Key and No Name Key region. Their habitat is under constant threat from sea level rise and increased human development.

Key deer eat leaves, shoots, flowers and fruit from many native plants. Mangroves and other salt-tolerant vegetation contribute to their diet, alongside plants in pinelands and hammocks. They are browsers rather than lawn specialists, and human food can disrupt nutrition and increase dangerous habituation. Their diet includes leaves, twigs, and fruits from over 150 plant species found in the Keys. Preferred food items include red mangrove, white mangrove, black mangrove, thatch palm berries, and various pineland herbs. Human food, including deer corn, is detrimental to their digestive system and contributes to nutrient deficiencies.

Common name

Key Deer

Scientific name

Odocoileus virginianus clavium

Animal group

Mammals

Size

61-81 cm at shoulder

Weight

20-34 kg

Lifespan

Not reliably established

Status

Assessment varies

Identification

The Key deer resembles other white-tailed deer, including the white underside of its raised tail, but is markedly smaller and naturally restricted to the lower Florida Keys. Adult males (bucks) typically grow antlers between April and September, shedding them in late winter. A distinguishing feature is their average size, with adult males standing about 24-30 inches at the shoulder and weighing 60-80 pounds, while females are slightly smaller. Key deer also have a distinct reddish-brown coat that can appear paler in summer.