Cuban Tree Frog (Osteopilus septentrionalis)

Order Anura, Family Hylidae (Tree Frogs), Genus Osteopilus, Species O. septentrionalis. This genus is known for species with skin fused to the skull (co-ossification), and this is the largest tree frog in North America.

Species

Family

Size

Adults typically range from 1.5 to 5 inches (3.8 to 12.7 cm). Females are significantly larger than males. This species is much larger than native North American tree frogs like the Green Tree Frog or Squirrel Tree Frog.

Conservation

IUCN Least Concern. However, in Florida and other introduced ranges, they are considered a harmful invasive species. Management often encourages the humane euthanasia of these frogs to protect native ecosystems.

Description

The Cuban Tree Frog is a formidable and adaptable amphibian. Often seen hunched in doorways or near lights, it has a distinct 'rubbery' and warty appearance. While impressive for its size and climbing ability, its presence in the US is a concern for biodiversity. It is a master of urban survival, utilizing human architecture for shelter.

Key Features

Large size (up to 5 inches), exceptionally large toe pads, warty skin, and skin fused to the skull. In the provided image, the frog’s tan/brown coloration and choice of a man-made crevice are classic indicators.

Physical Description

Large, robust tree frog with a broad head and prominent bulging eyes. The ears (tympanum) are large and distinct. It features exceptionally large, sticky toe pads used for climbing. The hind legs are long and powerful. A key anatomical trait is the skin on the top of the head being fused to the skull in adults.

Skin Texture & Coloration

Skin is highly variable, ranging from creamy white to bronze, brown, or olive green. It often displays mottled patterns or blotches. The texture is notably 'warty' or granular compared to other tree frogs. They can change color significantly based on temperature, light, and stress levels.

Distinguishing Features

Large toe pads (wider than the toes), warty skin, and large size. The most diagnostic feature is the skin on the head being 'fused' to the skull; if you gently rub the skin between the eyes, it does not move. They lack the dark 'eye mask' found in many other local tree frog species.

Habitat

Highly adaptable. Occupies wetlands, forests, and hammocks but thrives in urban and suburban landscapes. They are frequently found on houses, near outdoor lights, and in man-made structures like the sliding door track seen in the image.

Geographic Range

Native to Cuba, the Bahamas, and the Cayman Islands. It is an invasive species in Florida (where it is widespread), Georgia, South Carolina, and various Caribbean islands where it was not originally native.

Behavior

Nocturnal and highly predatory. They are known for 'synanthropic' behavior, meaning they live in close association with humans. They often hide in dark, moist crevices (like door tracks or pipes) during the day and hunt at night near porch lights that attract insects.

Diet & Feeding

Generalist carnivores. They eat almost anything they can fit in their mouths, including insects, spiders, snails, lizards, and other frogs. Their appetite for native frog species makes them a significant ecological threat in invaded areas.

Reproduction

Explosive breeders triggered by heavy rains and warm temperatures. They lay large clutches of eggs (up to 3,000) in various water sources, including ponds, swimming pools, birdbaths, and even clogged gutters. Amplexus is axillary.

Vocalizations

The call is described as a raspy, variable 'snore' or a 'croak' similar to a door hinge creaking. It is not musical like native hylids. In large choruses, the sound can be quite loud and abrasive.

Life Cycle

Typical frog life cycle: Egg to aquatic tadpole to terrestrial adult. Tadpoles are dark and develop quickly in warm water, often metamorphosing in as little as 3 to 4 weeks depending on food availability and temperature.

Conservation Status

Toxicity & Defense

Their skin produces a noxious mucus that can be irritating to human eyes and mucous membranes. It acts as a deterrent to predators. While not lethal to humans, it can cause significant discomfort or allergic reactions if touched and kemudian rubbed into eyes.

Ecological Role

In its native range, it is a mid-level predator. In its invasive range, it is a disruptive force that outcompetes and eats native frogs, leading to declines in indigenous amphibian populations.

Similar Species

Green Tree Frog (Dryophytes cinereus) – smaller, smoother skin, usually has a white lateral stripe. Squirrel Tree Frog (Dryophytes squirellus) – smaller, smoother, lacks the warty texture. Cope's Gray Tree Frog – warty but has bright yellow/orange on the inner thighs.

Observation Tips

Look near outdoor lights at night in Florida or the Caribbean. Check inside PVC pipes, under large leaves like bromeliads, or in the tracks of sliding glass doors and windows where moisture accumulates.

Handling & Safety

If handling is necessary, use gloves. The skin secretions can cause burning in the eyes and nose. Always wash hands thoroughly after contact. In Florida, wildlife authorities recommend not releasing them if captured due to their invasive status.

Seasonal Activity

Active year-round in tropical climates. In more temperate regions like North Florida, they become most active and vocal during the rainy summer months, often entering a period of reduced activity (brumation) during cold snaps.

Cultural Significance

Currently primarily known in North America as one of the most successful invasive vertebrates. They serve as a primary example in ecology of how adaptable species can displace native wildlife through competition and predation.

Interesting Facts

This frog can actually consume small birds and snakes. They are also known to cause short circuits in utility boxes and air conditioners when they crawl inside searching for moisture and cool air.

Identified on 6/23/2026