Jamaican boa  (Epicrates subflavus)

Classified as Vulnerable (VU) on the IUCN Red List (1) and listed on Appendix I of CITES (4).

As its common name suggests, this distinctive species is found only on Jamaica, and is the island’s largest, native, terrestrial predator (5). The colouration of the Jamaican boa varies over its length, with the upper part of the head usually appearing grey or olive-green, becoming golden yellow, orange or reddish-brown on the front part of the body (3). From the neck to the tail the body acquires an increasing degree of black colouration, with black crossbands on a yellow background exhibited on the mid-section, merging to form an almost uniform black region at the rear, except for some irregular yellow markings (2) (3). The scales of this species are iridescent and reflect a striking rainbow sheen when exposed to the light, especially at the darker rear-end of the body (3). The newborn Jamaican boa is pale orange on the upperparts, with dark orange or brown crossbands, and pinkish-orange on the belly. Captive specimens are known to acquire the adult colouration at around one and a half years old (3).

Endemic to Jamaica, the Jamaican boa occurs on the mainland, as well as on Goat Island, a small island off the southwest coast (6).

The Jamaican boa occurs in a variety of forest and woodland habitats, including humid, tropical and mountainous forest, dry limestone scrub-forest, moist woodland, swampland and mangroves (2) (3).

Active at night, the Jamaican boa seeks out prey by detecting chemical signals with its forked tongue as it moves stealthily through the trees. Once located, this species usually employs an ambush strategy, staying motionless until the animal comes within range. It then strikes swiftly, holding the victim in place with its needle-like teeth, while enveloping it in coils of its muscular body. Each time the prey exhales, the boa tightens its grip until eventually asphyxiation occurs, after which the animal is swallowed whole (3). Adults mainly feed upon rodents, bats and birds, while juveniles usually take lizards and frogs (2). While this species typically inhabits trees, as its habitat becomes increasingly altered, it is also being observed hunting on the ground. During the day, the Jamaican boa seeks refuge in dense foliage, tree hollows, cracks in rocks, or in underground burrows, although, in the early morning, it may be seen basking on rocks to raise its body temperature (3).

The Jamaican boa mates between February and April, with the onset of the breeding season stimulated by change in temperature, day length and rainfall. Females choose a mate by scent, selecting males which produce the most attractive pheromones. The female may mate with several males in a single breeding season, with each mating event lasting up to 24 hours, during which the two snakes’ bodies stay tightly intertwined. After fertilisation, the eggs are retained in the body, where they are nourished by yolk reserves for around six to seven months before hatching. The young, which may number between 5 and 44 individuals, are born live, each measuring around 50 centimetres in length. Captive specimens of the Jamaican boa have been known to live for over 30 years (3).

Once abundant throughout its range, the combined threats of persecution, habitat loss and the introduction of non-native species have had a catastrophic effect on the Jamaican boa’s population (3) (5) (7). The colonisation of the island by Europeans in the 1500s led to the introduction of predators such as cats, pigs and dogs, which not only compete for food with the boa, but also prey upon it directly (2) (5). Rats were also introduced by the European ships, and as an agricultural pest, their arrival prompted the deliberate introduction of the Asian mongoose, which also readily preys upon snakes (5). Along with predation, erroneous local beliefs that the snake is dangerous, as well as negative religious associations, have led to widespread persecution (3) (7). These threats are further compounded by ongoing habitat destruction, which has claimed over 90 percent of the snake’s habitat, and left the remaining areas fragmented (7). One of the last strongholds for this species, the largest remaining contiguous block of forest known as ‘Cockpit Country’, is now also being affected by bauxite mining and associated forest clearance and road building. Unless significant conservation action is undertaken, the Jamaican boa may eventually become extinct in the wild (5).

The Jamaican boa is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES), making all international trade in this species illegal (4). In addition, it is listed as a protected species under Jamaica’s Wildlife Protection Act, making the harming of the snake or possession of living or dead specimens an imprisonable offence (8). Unfortunately, however, persecution persists, as does the threat of habitat loss and degradation, therefore several conservation organisations are working to address these issues (8) (9) (10). A captive breeding program, begun in the 1970s at the Durrell Wildlife Conservation Trust, has shown great success, so that today, 14 institutions affiliated to the European Association of Zoos and Aquariums (EAZA) house Jamaican boa specimens (5) (7). In addition, education programmes are underway to educate local people about the snake’s precarious status and its benefit to humans, thereby diminishing persecution (7). Nevertheless, in order to assure the Jamaican boa’s survival, further work is still needed to protect this species’ habitat, and to eradicate exotic predators, such as the mongoose (2).

View information on this species at the UNEP World Conservation Monitoring Centre.

To learn more about the conservation of the Jamaican boa visit:

• Laboratory of Artificial and Natural Evolution:
  www.lanevol.org/LANE/jamboa.html
• Seven Oaks Sanctuary for Wildlife:
  http://soswildlife.jamaica.googlepages.com
• The Windsor Research Center:
  www.cockpitcountry.com/yellowboa.php