The other boid species currently on show at Bristol are our Cuban boas, Chilobothrus (formerly Epicrates) angulifer. These are fairly typical medium-sized (for boas) snakes, reaching around 3m usually, although a length of 4.8m is on record. They are confined to Cuba, and are currently classed as Near Threatened by the IUCN. The chief threats are human persecution and deforestation, but at present at least it is not as threatened as some of its relatives on other West Indian islands.
A recent study of the genetics of the ten living species of West Indian boas has shown they share a common ancestor on the mainland of South America. Formerly this was believed to be the ancestor of the modern Rainbow boa, Epicrates cenchria, but a study this year has shown that they split of from the stem that gave rise to the modern anacondas Eunectes, themselves closely related to Epicrates. As a result, they are now placed in the genus Chilobothrus instead. The Cuban boa seems to be the earliest surviving branch on the tree of West Indian boas, and seems to have split off from its relatives around 20m years ago. For more details, the paper can be found here: http://faculty.umb.edu/liam.revell/pdfs/Reynolds_etal_2013.MPE.pdf
In its ecology, the Cuban boa is something of a generalist, living in a variety of habitats including human altered ones. They mostly feed on mammals of various kinds, especially when larger, although they are recorded as feeding on Rock Iguanas Cyclura nubila on occasion. Before rats were introduced they probably fed largely on Cuban Hutias and other endemic species including bats, and when young probably take smaller lizards, birds, and amphibians as well.
Cuban Rock Iguana
One of the interesting features of their biology is the very small litter size. A female will have a maximum of seven, fairly large, young, which is an unusually small number for any reptile. Other Chilobothrus boas have more normal numbers, and the Jamaican boa has large numbers of very small young, which represents a completely different reproductive strategy. Producing large offspring is a drain on the females reserves, and in practise females probably breed at most every other year or less, further reducing lifetime reproductive output. This is an indication that survival of the young in natural circumstances must be quite high, and even when young boas do not face a large number of natural enemies. Another feature of this lifestyle is a long lifespan, and in captivity Cuban boas can live to over 30 years.
As with most boas, Cuban boas are nocturnal, emerging after dark to locate their prey. They have quite prominent heat detecting pits in the upper lip, which assists in locating warm-blooded prey after dark. Smaller individuals spend more time in trees, but larger ones are probably more terrestrial, occupying caves and holes in the ground.
In captivity, care for Cuban boas is straightforward, and similar to that for Common Boas Boa constrictor. Given the large size of adults however, a large enclosure is required, with plentiful opportunity for climbing, and they tend to be rather snappy. Although there are Cuban Boas in private hands, for this reason they do not make good pet snakes, except for dedicated hobbyists.