Osteopilus septentrionalis, commonly known as the
Cuban tree frog, is an amphibian native to the
CaribbeanThe Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
region of the
Western HemisphereThe Western Hemisphere or western hemisphere is mainly used as a geographical term for the half of the Earth that lies west of the Prime Meridian and east of the Antimeridian , the other half being called the Eastern Hemisphere.In this sense, the western hemisphere consists of the western portions...
. It is the largest tree frog of North America. Their wide diet and ability to thrive amongst humans has made it a highly
invasive species"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
with established colonies in Northern Florida, the Hawaiian island of
OahuOahu or Oahu , known as "The Gathering Place", is the third largest of the Hawaiian Islands and most populous of the islands in the U.S. state of Hawaii. The state capital Honolulu is located on the southeast coast...
, and thorough the Caribbean Islands. They range in size from 3 to 5.5 in (7.6 to 14 ) and vary in color from olive-brown, bronze, gray, or grayish-white. A nocturnal tree dwelling frog, they are known to eat almost anything that will fit in their mouth and to mate year-round. Their arrival in a new community is believed to be detrimental to local species and it has been suggested that these frogs be destroyed on sight upon their arrival in new habitats. Cuban tree frogs are commonly available as pets; however, because the animal secretes a toxic mucus from their skin that can cause a burning sensation in the eyes it is not an ideal pet. It is also believed that further distribution of the species has been expanded by the release of these pets.
Description
The Cuban tree frogs range in size from 3 to 5.5 in (7.6 to 14 ) in length. It is the largest tree frog in
North AmericaNorth America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and has a rough warty skin. Their toepads are much larger than those of other tree frogs and they will often have an orange-tint to their eyes. Varying in color from, olive-brown, bronze, gray, or grayish-white.
Cuban tree frogs can change colors depending on their temperature and environment. Many individuals have darker splotches on the back, and some splotchy banding on the legs. In many individuals, the hidden surfaces of the legs are bright yellow. When the frog leaps to avoid a predator, these bright yellow patches are visible, and may help to confuse the predator.
Also, the skin on their heads is fused to the skull—if the head of an adult frog is rubbed (between the eyes), the skin does not move. This is a special adaptation that prevents water loss, since there are fewer blood vessels in the "co-ossified" (fused) area. When handled, Cuban tree frogs secrete a toxic mucus from their skin. In humans, this can cause an allergic reaction or burning sensation to the eyes and nose, and even trigger asthma.
Behavior
Excellent climbers the Cuban tree frogs will typically sleep above ground during the day. During the night Cuban tree frogs forage for insects in sources of artificial light. Indiscriminate predators they will eat anything they can overpower and fits into their mouth, including:
snailSnail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s,
spiderSpiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s,
insectInsects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, other
frogFrogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s (even other Cuban tree frogs),
snakeSnakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s,
lizardLizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s, small
crustaceanCrustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, and
hatchling birdsIn oviparous biology, a hatchling is the newborn of animals that develop and emerge from within hard-shell eggs. The offspring of birds are often hatched naked and with their eyes closed. The hatchling relies totally on its parents for feeding and warmth. Hatchlings precede nestlings in the chick's...
in their nest. Their foraging will occasionally take them up
utility poleA utility pole is a pole used to support overhead power lines and various other public utilities, such as cable, fibre optic cable, and related equipment such as transformers and street lights. It can be referred to as a telephone pole, power pole, hydro pole, telegraph pole, or telegraph post,...
s where they can cause short-circuits of utility switches, causing costly power outages.
Life cycle
Cuban tree frogs are sexually dimorphic–females are larger than males. Breeding males can be identified by their development of black
nuptial padA nuptial pad is a secondary sex characteristic present on some mature male frogs and salamanders. Triggered by androgen hormones, this breeding gland appears as a spiked epithelial swelling on the forearm and prepollex that aids with grip, used primarily by males to grasp females during amplexus...
s on their thumbs, which help the male to hold onto the female during mating.
Cuban tree frogs breed year round, but most commonly occurs in the wet season, between May and October. Optimal conditions are considered to be 81.5 °F (27.5 °C) with high humidity (97.8%) and rain. They lay a partial
clutchA clutch of eggs refers to all the eggs produced by birds or reptiles, often at a single time, particularly those laid in a nest.In birds, destruction of a clutch by predators, , results in double-clutching...
of eggs in varying size ranging from 100-1,000. The full clutch is average a total of 3,961 and varies based on female body size. Eggs can hatch in under 30 hours and can fully develop in 1 month. Much like their adult counter parts newly hatched
tadpoleA tadpole or polliwog is the wholly aquatic larval stage in the life cycle of an amphibian, particularly that of a frog or toad.- Appellation :...
s can come in a variety of colors and patterns. They have a wide caudal fin and two rows of labial teeth on the top of the mouth and four rows on the bottom. Tadpoles survive off of
algaeAlgae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
and will occasionally turn to cannibalism eating other tadpoles and on rare occasions recently metamorphism juveniles. After transformation are between 0.55 and 0.67 in (1.4 and 1.7 ), while the tail is entirely absorbed.
Distribution
The Cuban tree frog is native to
CubaThe Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
, the Bahamas, and the
Cayman IslandsThe Cayman Islands is a British Overseas Territory and overseas territory of the European Union located in the western Caribbean Sea. The territory comprises the three islands of Grand Cayman, Cayman Brac, and Little Cayman, located south of Cuba and northwest of Jamaica...
. This large frog has been introduced in
Puerto RicoPuerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
, the U.S. Virgin Islands, the
British Virgin IslandsThe Virgin Islands, often called the British Virgin Islands , is a British overseas territory and overseas territory of the European Union, located in the Caribbean to the east of Puerto Rico. The islands make up part of the Virgin Islands archipelago, the remaining islands constituting the U.S...
, many islands of the
Lesser AntillesThe Lesser Antilles are a long, partly volcanic island arc in the Western Hemisphere. Most of its islands form the eastern boundary of the Caribbean Sea with the Atlantic Ocean, with the remainder located in the southern Caribbean just north of South America...
, and
HawaiiHawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
. There is debate over if the species was native to the
Key WestKey West is an island in the Straits of Florida on the North American continent at the southernmost tip of the Florida Keys. Key West is home to the southernmost point in the Continental United States; the island is about from Cuba....
region of
FloridaFlorida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, or if it was introduced to the area. First discovered in the 1930s, it is theorized that they might arrived on ships in the 1800s or could have made it to the area by natural means. They can survive in
brackish waterBrackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
and this ability may have helped the species to spread to various islands. The Cuban tree frogs progressed colonization into the mainland of Florida is believed to be by use of
Florida State Road A1AState Road A1A is a Florida State Road that runs mostly along the Atlantic Ocean, with sections from Key West at the southern tip of Florida, to Callahan, just south of Georgia. It is the main road through most oceanfront towns. SR A1A is designated the A1A Scenic and Historic Coastal Highway, a...
construction during the 1940s. The species is now established in southern Florida and parts of the
panhandle regionThe Florida Panhandle, an informal, unofficial term for the northwestern part of Florida, is a strip of land roughly 200 miles long and 50 to 100 miles wide , lying between Alabama on the north and the west, Georgia also on the north, and the Gulf of Mexico to the south. Its eastern boundary is...
and can be found as far north as
South CarolinaSouth Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
.
The Cuban tree frog is known to hitchhike on shipments of potted plants, vegetation, packaging, boats, and other motorized vehicles. Once in a new location the frogs become an
invasive species"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
. They have several good colonizing traits, such as: high
fecundityFecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...
, short generation time, a diverse diet, good competitive ability, and the ability to co-exist with humans. In addition they also secrete a toxic mucus from their skin which helps to limit the number of natural predators.
Cuban tree frogs are known to inhabit a variety of communities, including
estuaryAn estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
s, low-density suburban development, small towns, agricultural areas, particularly ones with exotic plants, and lowland forests and swamps. Within their habitat they can be found in damp, shady areas, particularly around shrubs and trees, by cisterns, rain barrels, and buildings.
Conservation
The large frog directly impacts native ecosystems by eating native frogs, lizards, and snakes and poses a threat to the
biodiversityBiodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
of the areas into which it spreads by causing native tree frog populations to decline. These effects are most noticeable in urban and suburban areas, where native tree frogs such as the
American green tree frogThe American green tree frog is a common species of New World tree frog belonging to the genus Hyla. It is a common backyard species that is popular as a pet, and is the state amphibian of Georgia and Louisiana.-Description:...
(
Hyla cinerea) and the Squirrel treefrog (
Hyla squirella) are rapidly disappearing.
It has spread throughout peninsular Florida, and is also commonly found in isolated populations as far north as southern Georgia. It hitchhikes on vehicles or ornamental plants, spreading to new areas, and has been transported as far north as Canada. Because of its effects on the biodiversity some experts have recommended killing the animal when it is found in a new habitat.
In captivity
Cuban tree frogs are commonly available in the
petA pet is a household animal kept for companionship and a person's enjoyment, as opposed to wild animals or to livestock, laboratory animals, working animals or sport animals, which are kept for economic or productive reasons. The most popular pets are noted for their loyal or playful...
trade within the United States. They are inexpensive, and when cared for properly tend to live 5–10 years. They feed readily on commercially available
cricketsCrickets, family Gryllidae , are insects somewhat related to grasshoppers, and more closely related to katydids or bush crickets . They have somewhat flattened bodies and long antennae. There are about 900 species of crickets...
, however while in captivity they may turn to cannibalism. The skin of Cuban tree frogs secretes a toxic mucus that can burn the eyes and trigger an allergic (or asthmatic) reaction; as a result, this species is not an ideal pet species, especially for children.
The Cuban tree frog's colonization of the Hawaiian island of
OahuOahu or Oahu , known as "The Gathering Place", is the third largest of the Hawaiian Islands and most populous of the islands in the U.S. state of Hawaii. The state capital Honolulu is located on the southeast coast...
is believed to be a result of accidental or deliberate release of a pets. Therefore the Species is now banned from sale in Hawaii. Conviction of importation of a Cuban tree frog carries a maximum fine of $25,000 and a year in jail.
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