Caicos Islands dwarf boa  (Tropidophis greenwayi)

The Caicos Islands dwarf boa has yet to be classified on the IUCN Red List. It is listed on Appendix II of CITES (3).

The Caicos Islands dwarf boa (Tropidophis greenwayi) is, as its name suggests, a small, stout-bodied snake which is endemic to the Caicos Islands. The colour and pattern of the Caicos Islands dwarf boa varies widely, although it is usually uniform dark brown on the back of the head, becoming slightly paler on the neck and body. A wide greyish-tan stripe runs along the back and the upper surface of the tail, and there are usually two rows of dark brown blotches, outlined with pale grey, running down the centre (4).

The head of the Caicos Islands dwarf boa is black and white, mixed with mottled browns and tans, with flecks of cream on the dark brown scales that border the mouth. The sides of the body are dark brown and somewhat blotchy, becoming redder underneath, while the underside of the Caicos Islands dwarf boa is reddish-tan to chocolate brown, with two rows of dark brown blotches. The tip of the tail is yellow (4).   

The Caicos Islands dwarf boa is endemic to the Caicos Islands, where it is only found on six of the islands and cays, including South Caicos, Middleton Cay, Long Cay, North Caicos, Middle Caicos and Ambergris Cay. Some reports suggest the Caicos Islands dwarf boa may also be found on the island of Providenciales, although its presence there is currently unconfirmed (2) (5). 

The Caicos Islands dwarf boa is found mainly under limestone rocks in areas of rocky coppice or dense scrub, although it is known to inhabit most types of habitat apart from beaches, marshes and lakes (2) (4).

Typically a rather secretive snake, the Caicos Islands dwarf boa is active only at night. It forages on the ground, where it feeds primarily on lizards of the genus Anolis, and on frogs, particularly Eleutherodactylus species (6) (7). It may also occasionally feed on invertebrates (8). When disturbed or threatened, the Caicos Islands dwarf boa exhibits a characteristic defensive behaviour, coiling itself up into a tight ball and hiding its head, smearing a foul-smelling fluid onto its coils and exposing its bright yellow tail (2) (4).

The Caicos Islands dwarf boa is viviparous, giving birth to two or three very small live young (7) (8). Although very little is known about its breeding in the wild, individuals in captivity have been observed mating between late January and February, with the young born in early June, to coincide with the onset of the rainy season. The female Caicos Islands dwarf boa becomes sexually mature after reaching a length of around 22 centimetres and a weight of between 9 and 10.5 grams (4).

The conservation status of the Caicos Islands dwarf boa is currently unknown, although the population is thought to be declining. The main threats to this species include habitat loss and introduced species, and it is also frequently killed by local islanders or sold into the pet trade (2) (5). 

There are no known conservation measures in place for the Caicos Islands dwarf boa. Distribution surveys and population status monitoring of this species are urgently needed in all remaining areas of suitable habitat throughout the Turks and Caicos Islands (5).

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Find out more about the Caicos Islands dwarf boa:

• Iverson, J. B. (1986) Notes on the natural history of the Caicos Islands dwarf boa, Tropidophis greenwayi. Caribbean Journal of Science. 22(3-4): 191-198. Available at:
  http://academic.uprm.edu/publications/cjs/VOL22/P191-198.PDF

 Find out more about the conservation of reptiles:

• The Herpetological Conservation Trust:
  http://www.herpconstrust.org.uk/

 Find out more about conservation of reptiles in the UK Overseas Territories:

• United Kingdom Overseas Territories Conservation Forum:
  http://www.ukotcf.org/
• Edgar, P. (2009) The Amphibians and Reptiles of the UK Overseas Territories, Crown Dependencies and Sovereign Base Areas: Species Inventory and Overview of Conservation and Research Priorities. Herpetological Conservation Trust, Dorset. Available at:
  http://www.herpconstrust.org.uk/downloads/UKOT%20Herps%20Report%20-%20Version%2001%20March%202009.pdf