Acklins Ground Iguana
Encyclopedia
Cyclura rileyi nuchalis, commonly known as the Acklins Ground Iguana or Watling Island Iguana, is an endangered subspecies
of lizard
of the genus Cyclura
it is one of three subspecific forms of Cyclura rileyi
in the Iguanidae
family.
, recognized as such since 1975. The species is listed as endangered according to the current IUCN Red List.
Its generic
name (Cyclura
) is derived from the Ancient Greek
cyclos (κύκλος) meaning "circular" and ourá (οὐρά) meaning "tail", after the thick-ringed tail characteristic of all Cyclura iguanas. Its specific name, rileyi, is a Latinized form of the name of American biologist
, Joseph Harvey Riley
. Its subspecific name,nuchalis, is Latin for "neck
" in reference to the thick scalation around the animal's neck.
Like other members of the genus Cyclura
, males of this subspecies are larger than females, and have more prominent dorsal
crests in addition to prominent femoral pore
s on their thighs, which are used to release pheromones. Females have less prominent pores and have shorter crests than the males making the animals sexually dimorphic
.
s in the Bahamas
and is described as endangered according to the current IUCN Red List.
Natural populations of Acklins Ground Iguanas are found only on Fish Cay and North Cay in the Acklins
Bight, Bahamas. They formerly inhabited Long (Fortune) Cay. An additional introduced population with five founding individuals was established on a small cay in the early 1970s.
These two populations are made up of 12,500-18,800 individual animals. A translocated population in the Exumas Land and Sea Park contains 300 animals and appears to be stable.
species the Acklins Ground Iguana is primarily herbivorous
, 95% of which from consuming leaves
, flower
s and fruit
s from 7 different plant species such as Seaside Rock Shrub (Rachicallis americana), and Erect Prickly Pear (Opuntia stricta
). This diet is very rarely supplemented with animal matter, although a wild specimen has been recorded eating mice
.
s, heron
s, kestrel
s and seagulls have minimal impact on the populations.
The Acklins Cays also have an abundance of food and vegetation compared to the cays on which other iguanas are found and this also must be considered as a factor in their success. Sea level rise may be the greatest threat these animals face in the future, as the cays lack elevation relief and a sea level rise of 1 meter over the next 100 years could cost the cays up to 50% habitat loss.
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
of the genus Cyclura
Cyclura
Cyclura is a genus of lizards from the family Iguanidae. Members of this genus are known as "cyclurids" or more commonly as rock iguanas and only occur on islands in the West Indies...
it is one of three subspecific forms of Cyclura rileyi
Cyclura rileyi
Cyclura rileyi, commonly known as the San Salvador Rock Iguana or Bahamian Rock Iguana, is a critically endangered species of lizard of the genus Cyclura native to three island groups in the Bahamas. The species is in decline due to habitat encroachment by human development and predation by feral...
in the Iguanidae
Iguanidae
Iguanidae is a family of lizards, composed of iguanas and related species.-Classification of Iguanidae:Two different classification schemes have been used to define the structure of this family. These are the "traditional" classification and the classification presented by Frost et al. .Frost et...
family.
Taxonomy
The Acklins Ground iguana is a recognized subspecies of the San Salvador Rock IguanaCyclura rileyi
Cyclura rileyi, commonly known as the San Salvador Rock Iguana or Bahamian Rock Iguana, is a critically endangered species of lizard of the genus Cyclura native to three island groups in the Bahamas. The species is in decline due to habitat encroachment by human development and predation by feral...
, recognized as such since 1975. The species is listed as endangered according to the current IUCN Red List.
Its generic
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
name (Cyclura
Cyclura
Cyclura is a genus of lizards from the family Iguanidae. Members of this genus are known as "cyclurids" or more commonly as rock iguanas and only occur on islands in the West Indies...
) is derived from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
cyclos (κύκλος) meaning "circular" and ourá (οὐρά) meaning "tail", after the thick-ringed tail characteristic of all Cyclura iguanas. Its specific name, rileyi, is a Latinized form of the name of American biologist
Biologist
A biologist is a scientist devoted to and producing results in biology through the study of life. Typically biologists study organisms and their relationship to their environment. Biologists involved in basic research attempt to discover underlying mechanisms that govern how organisms work...
, Joseph Harvey Riley
Joseph Harvey Riley
Joseph Harvey Riley was an American ornithologist.Born in Falls Church, Virginia, Riley was employed at the Smithsonian Institution from 1896 until his death, becoming Associate Curator of the Division of Birds in 1932.-Sources:*...
. Its subspecific name,nuchalis, is Latin for "neck
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...
" in reference to the thick scalation around the animal's neck.
Anatomy and morphology
Acklins Ground Iguana strongly resembles the San Salvador Rock Iguana in color and shape. The lizard's back color can range from red, orange or yellow, to green, brown or grey, usually patterned by darker markings. The very brightest colors (red, orange or yellow) are normally only displayed by males and are more pronounced which at warmer body temperatures. Immature iguanas lack these bright colors, being either solid brown or grey with faint slightly darker stripes. What makes this iguana stand out from the other two subspecies is the scalation on its neck and head.Like other members of the genus Cyclura
Cyclura
Cyclura is a genus of lizards from the family Iguanidae. Members of this genus are known as "cyclurids" or more commonly as rock iguanas and only occur on islands in the West Indies...
, males of this subspecies are larger than females, and have more prominent dorsal
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
crests in addition to prominent femoral pore
Femoral pore
Femoral pores are a part of a holocrine secretory gland found on the inside of the thighs of certain lizards and amphisbaenians which releases pheromones to attract mates or mark territory. In certain species only the male has these pores and in other species, both sexes have them, with the males...
s on their thighs, which are used to release pheromones. Females have less prominent pores and have shorter crests than the males making the animals sexually dimorphic
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
.
Distribution
The Acklins Ground Iguana is endemic to three small cayCay
A cay , also spelled caye or key, is a small, low-elevation, sandy island formed on the surface of coral reefs. Cays occur in tropical environments throughout the Pacific, Atlantic and Indian Oceans , where they provide habitable and agricultural land for hundreds of thousands of people...
s in the Bahamas
The Bahamas
The Bahamas , officially the Commonwealth of the Bahamas, is a nation consisting of 29 islands, 661 cays, and 2,387 islets . It is located in the Atlantic Ocean north of Cuba and Hispaniola , northwest of the Turks and Caicos Islands, and southeast of the United States...
and is described as endangered according to the current IUCN Red List.
Natural populations of Acklins Ground Iguanas are found only on Fish Cay and North Cay in the Acklins
Acklins
Acklins is an island and district of the Bahamas.It is one of a group of islands arranged along a large, shallow lagoon called the Bight of Acklins, of which the largest are Crooked Island in the north and Acklins in the southeast, and the smaller are Long Cay [ 8sq mi] in the northwest, and...
Bight, Bahamas. They formerly inhabited Long (Fortune) Cay. An additional introduced population with five founding individuals was established on a small cay in the early 1970s.
These two populations are made up of 12,500-18,800 individual animals. A translocated population in the Exumas Land and Sea Park contains 300 animals and appears to be stable.
Diet
Like all CycluraCyclura
Cyclura is a genus of lizards from the family Iguanidae. Members of this genus are known as "cyclurids" or more commonly as rock iguanas and only occur on islands in the West Indies...
species the Acklins Ground Iguana is primarily herbivorous
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
, 95% of which from consuming leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
, flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s and fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
s from 7 different plant species such as Seaside Rock Shrub (Rachicallis americana), and Erect Prickly Pear (Opuntia stricta
Opuntia stricta
Opuntia stricta is a species of cactus from southern North America, Central America, the Caribbean, and northern South America. Common names include Erect Prickly Pear and Nopal Estricto ....
). This diet is very rarely supplemented with animal matter, although a wild specimen has been recorded eating mice
Mouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
.
Mating
Mating occurs between May and June depending on when the dry season ends, and 2-5 eggs are usually laid within 40 days depending on the size and age of the female. Some females have been observed migrating to coastal areas on the various cays in order to build their nests in the sand, and some guard the nest site for a short period of time. The hatchlings emerge from the nests in August to early September.Habitat
Unlike every other species of Cyclura the Acklins Ground Iguana is free of threats by feral predators. The cays they dwell on are remote and human populations leave the animals undisturbed. Natural predators in the form of ospreyOsprey
The Osprey , sometimes known as the sea hawk or fish eagle, is a diurnal, fish-eating bird of prey. It is a large raptor, reaching more than in length and across the wings...
s, heron
Heron
The herons are long-legged freshwater and coastal birds in the family Ardeidae. There are 64 recognised species in this family. Some are called "egrets" or "bitterns" instead of "heron"....
s, kestrel
Kestrel
The name kestrel, is given to several different members of the falcon genus, Falco. Kestrels are most easily distinguished by their typical hunting behaviour which is to hover at a height of around over open country and swoop down on prey, usually small mammals, lizards or large insects...
s and seagulls have minimal impact on the populations.
The Acklins Cays also have an abundance of food and vegetation compared to the cays on which other iguanas are found and this also must be considered as a factor in their success. Sea level rise may be the greatest threat these animals face in the future, as the cays lack elevation relief and a sea level rise of 1 meter over the next 100 years could cost the cays up to 50% habitat loss.