metazoa12

Saint Lucian viper, Bothrops caribbaeus, juvenile. Troumassee Bay, south-eastern Saint Lucia, Lesser Antilles.

The Latin verb fascinare translates as "to bewitch". In the English language it is especially predicated of serpents, believed to be able to hold other creatures under the spell of their unblinking eyes, immobilizing them to a place.

The ancient Maya expressed their fascination and almost numinous awe by naming one of their main deities the "Feathered Serpent": K'uk ul-Kán.

Snakes are really a clade of lizards and evolved in a relatively recent geological past. They might share a common ancestor with the monitors (Varanidae) and water monitors (Lanthanotidae) of the Old World, and with the Gila monster and the beaded lizard (Helodermatidae) of North America.

There is no single trait that unequivocally separates snakes from lizards, so maintaining the two groups as distinct entities is mainly a matter of verbal tradition. Together with the several groups of legless lizards, snakes form a sort of morphological continuum. The four traits that are often invoked to distinguish snakes are: a tail shorter than the elongated body, lack of external ears, lack of movable eyelids, and a forked tongue. However, amphisbaenians (treated in their own section in this website) possess all these, as well. So, should amphisbaenians be considered a peculiar kind of snakes, or are ophidians nothing but an ill-defined group of lizards?

... snakes are Cosmopolitan in distribution, living everywhere save for Antarctica and the most remote oceanic islands. They have also adapted to all habitats within their extensive range save for constantly snow-clad mountain summits.

This resting position is common among arboreal and semi-arboreal boids and pythonids: tightly coiled on a branch with the head in a central position.
Captive greater Puerto Rican boa, Chilabothrus inornatus, male.

While some lizards - like large iguanids and uromasticids - are mainly herbivorous, such is not the case with any snake. Each and every known species is a predator that, according to its size, feeds on anything from insects and slugs, to large mammals like deer and antelope. As happens with many of their lizard relatives, many diurnal snakes have very good color vision. Snakes usually hunt by reacting to the movement of their prey. If the potential victim does not move, it will frequently escape detection. However, some species, especially among nocturnal ones, can scavenge dead animals, which they find by smell. The same applies to a few species that specialize in feeding on the eggs of birds and amphibians.

Ophidians are well known worldwide for their capacity to swallow prey wider than their own girth. This feat is accomplished by highly kinetic jaws that are united at the chin not by bone, but by an elastic set of tendons and cartilages. Many species can also open their jaws at an almost 180-degree angle. Most snakes have two rows of upper teeth: two on the maxilla and two on the palate (for a total of six, including the two on the mandibles) and, in most cases, the maxilla (to which the two outer rows of upper teeth are attached) is itself loosely hinged to the skull. Once the prey is seized (and usually killed first by one of several means, like the use of venom or constriction) each jaw bone moves independently from the other, back and forth, slowly "walking" the prey down the throat. So that the reptile does not asphyxiate during the sometimes lengthy process of swallowing a food item, the front end of the trachea ends on the floor of the mouth itself, right behind the tongue, and is pushed forward and opened every so often to take a breath of air.

A male Puerto Rican racer, (nominate race, Borikenophis portoricensis portoricensis) devours a

male Puerto Rican crested anole, (nominate race, Anolis cristatellus cristatellus).

A female greater Puerto Rican boa, Chilabothrus inornatus, devours a chicken that it captured in a tree.

The bird is almost three times the girth of the snake, and it took the reptile almost two hours to swallow its victim.

The snake hangs from its short but muscular and prehensile tail, while the rest of its body coils around the prey.

Small, active species will eat as frequently as they can. However, a large boa, python, or Gaboon viper can fast for more than a year, if conditions require it. It is this capacity to go without food for long periods of time what has allowed snakes of one species or another to invade many of the most remote islands, some of them located thousands of kilometers from the nearest continent.

True to their predatory habits, an ophidian's teeth are needle-sharp and point backwards. They are totally unsuitable for chewing, but serve merely for seizing, restraining, and swallowing their victims.

Snakes can be classified (though not in a properly phylogenetic way) according to their envenoming apparatus, or lack thereof. Those that maintain the ancestral condition common to all lack proper venom-producing and -injecting systems, are called "aglyphs" (Greek for "without a groove"). On the other hand, many colubrids and dipsadids have one or more pairs of enlarged teeth near the back of the mouth, each with a open groove on their front edge, and located close to the hinge between the maxilla and the mandible. Such snakes exhibit the "opistoglyph" ("rear groove") condition. These snakes lack true venom-producing organs, and instead have a pair of Duvernoy's glands that open at the bases of the fangs, and secrete toxins that mix with the normal saliva and are rather inefficiently injected into a wound. Snakes with fixed, enlarged fangs near the front of their mouths, each having a deep and partially closed groove, are "proteroglyphs" ("anterior groove"). These snakes are the elapids (cobras, mambas, tiger snakes, coral snakes, taipans, and their relatives) and the hydrophiids (sea snakes). Species with highly modified fangs hinged to the upper jaw through the maxilla, each having a completely closed groove (effectively turning the fang into a syringe) are called "solenoglyphs" ("groove and channel"). Such snakes are the viperids (vipers), and the atractaspidids.

All of a snake's teeth are shed and replaced periodically, so that the animal always has a functional set of them.

The venom of a snake not only serves to slow down or kill the animals it hunts, but in many cases it actually begins digesting them from the inside out, even before the predator has ingested them. Snake venom is actually a modified saliva with a very high protein and enzyme content. In varying degrees, depending on the species, the venom can be either neurotoxic, attacking the autonomous nervous system of the victim (and thus, often disturbing or paralyzing functions like heart contractions and breathing) or hemotoxic, which directly destroys tissue (frequently causing massive internal bleeding). Sometimes, a snake's venom is a combination of both basic sorts of toxins.

A juvenile Puerto Rican racer, (southern race, Borikenophis portoricensis prymnus), captures and devours a juvenile Puerto Rican giant whiptail, Pholidoscelis exsul.
Camp Santiago, south-eastern Puerto Rico.
Within seconds of the first bite on the lizard's neck, it started to vomit blood, attesting to the powerful (for other reptiles) hemolitic venom of the snake, which destroys blood cells and other tissues.
The racer took only three minutes to dispatch its prey. These snakes are mostly harmless to humans and retiring in temperament.

While the independently mobile jawbones are not actually universal in snakes, as far as it is known all snakes do possess an acute sense of smell, extended partially to their thin and protractile tongues, which can "taste" the air when waved outside the mouth. Their tongues also transmit odor molecules to the vomeronasal (or "Jacobson's") organ that opens into the palate, further enhancing their olfactory powers. (The vomeronasal organ is also present and similarly used in many families of lizards, amphibians, and mammals, though ours is merely vestigial).

Like most snakes, a greater Puerto Rican boa, Chilabothrus inornatus, has a small aperture in the upper lip at the tip of the snout.

The tongue is protruded through such, flicked in the air, and then inserted inside the vomeronasal organ on the palate, which collects and analyses odor molecules.

Most snakes have only one functional lung, usually the right one. The great majority are terrestrial, although some are highly aquatic in freshwater habitats, and members of the Indopacific family Hidrophiidae are truly marine, to the point of mating and then giving birth to live offspring at sea. Many terrestrial species are highly adapted to a life on trees and, among these, many boids and pythonids have short yet strongly prehensile tails.

Unlike other groups of reptiles, like crocodilians and even some lizards, snakes are voiceless. At most, some will hiss when threatened by expelling air forcefully through their throats.

Venomous or not, most snakes are shy, retiring animals. Almost all attacks on man are in one way or another provoked, and occur due to the fact that the animal is not so much aggressive as it is frightened, and seeks to defend itself from a perceived attacker. Only two or three species, for example, the African black mamba (Dendroaspis polylepis) are known to occasionally go out of their way to pursue and bite a human. Even in such cases, the attack is a territorial response, and certainly not carried out because of hunger. (Only a few pythonids, like the reticulated python of eastern Asia, and the rock python of Africa, are known to be able to swallow a human being, and even those cases are rare in the extreme).

Snakes have been maligned, feared and despised by peoples of many cultures, with very little on the way of rational discourse for doing so. These biases are often perpetuated by nonsensical religious traditions or the unthinking repetition of superstitious statements. This last is the case in practically all the Antilles, where any and every snake will be killed on sight as an "evil" creature, even as poisonous snakes are notoriously absent from most of these islands. The fact is that although a number of species on Earth can be truly dangerous, a snake will almost invariably leave you alone if you leave it alone and do not do something stupid. While many people find it very difficult to lay aside their biases and phobias against snakes, the fact is that most people are at far greater risk of being mauled or kicked to death by a domestic dog or horse, or of being stung to death by bees, that of being killed by any given snake. In most cases (including a few I personally know of) where a human has been bitten by a snake, the incident was due to either clumsiness or childish bravado on the part of the person.

Several groups of snakes are represented in the West Indies. Although not as numerous as lizards, there are still about 123 native ophidian species in this region, and they comprise a sizable element of the local herpetofauna.

Six families of snakes are native in the West Indies: Boidae, Colubridae, Crotalidae, Leptotyphlopidae, Tropidophiidae, and Typhlopidae.

These are fossorial, burrowing snakes that seem to be the most primitive members of the entire group. They often have vestigial pelvic girdles and are usually small in size.

Worldwide, several families of snakes are highly specialized burrowers. Among them some groups, like the leptotyphlopids, have taken their fossorial existence to such extremes that they actually look like thin earthworms. Threadsnakes feed, like typhlopids, on very small insects like ants and termites.

Superficially similar to typhlopids (below), yet only distantly related to them, the family Leptotyphlopidae is present in the Antilles. However, they exhibit a strangely disjunct distribution in The Bahamas, Hispaniola, and a few of the Lesser Antilles, while many intervening islands are seemingly devoid of them.

New World members of the family belong in the subfamily Epictinae. The genus Epictia is found in the Neotropical continent regions, with two species present in an Salvador (The Bahamas) and San Andres. Mitophis is an endemic Hispaniolan taxon containing 5 species. Tetracheilostoma is endemic to the Lesser Antillean islands of Martinique, Saint Lucia, and Barbados. The last homes the smallest snake on Earth: Tetracheilostoma carlae.

Compared to the similar threadsnakes, typhlopids are much more widely distributed throughout the Caribbean.

Many blind snakes of the genus Amerotyphlops, Antillotyphlops, Cubatyphlops and Typhlops are known to inhabit the Greater Antilles, The Bahamas, and some of the Lesser Antilles. The first genus is widely spread throughout the mainland Neotropics with but one known species in the Antilles. The other three are mainly West Indian in distribution. The family itself is truly Cosmopolitan.

Typhlopids have vestigial eyes discernible under the skin of the head as tiny, dark dots.

Many have a sharp scale at the end of the tail, used to anchor themselves as they burrow underground. With such, they can also prick any predator that threatens them.

First photograph: Puerto Rican brown-bellied blindsnake, Typhlops rostellatus. Florida, central Puerto Rico.

Second photograph: coastal dwarf blind snake, Antillotyphlops hypomethes. Fort Buchanan, Guaynabo, north-eastern Puerto Rico.

Bahoruco blindsnake, Typhlops eperopeus. Near Cabral, south-western Dominican Republic, Hispaniola.

They usually are larger and heavier than threadsnakes, but still exhibit the same basic lifestyle and occupy a similar niche underground. Able to distinguish only between light and darkness, their eyes are reduced to tiny dark spots under the skin. Their bodies are almost perfectly cylindrical, and their scales are small, smooth, and tightly set, all of these being adaptations to a subterranean existence. Additionally, many typhlopids have a sharp, pointed scale on the tip of their very short tails. With such, they can inflict a startling but totally harmless prick on any hand that holds them.

Living under termitaria, rocks, and fallen logs, they "swim" easily into loose soil when their lair is disturbed. They feed mainly on the bodily fluids of small insects, like termites and ants.

Virgin Islands blindsnake, Antillotyphlops richardi. Crown Mountain, Saint Thomas, United States Virgin Islands.

One of the minute members of the typhlopid family: the tiny Guanica blindsnake Antillotyphlops granti.

Females lay a few eggs at a time, often only two or three and seemingly very large for the size of the animal. These eggs are laid in their usual lairs under objects resting on the ground.

Because they all have the same basic ecology, inhabit the same microhabitat and, thus, are very similar to one another, the many species of typhlopids can be very difficult to distinguish from one another at first glance, even by experts. Often, the best way to be certain as to their identity is through the rather tedious process of counting the rows of scales on their bodies.

Puerto Rican white-tailed blindsnakes, Antillotyphlops platycephalus. Aside from T. granti (above), this is the only species in its insular bank that is [somewhat] easy to tell apart by its color.
It is also peculiar in its distribution, since it is also found in some of The Bahamas, probably having reached there by over water dispersal from Puerto Rico.

Puerto Rican white-tailed blindsnake. Turks and Caicos. Actually, it probably is a different species from the Puerto Rican population.
(Photograph courtesy of Mr. Joseph Burgess).

Saint Barthelemy's blind snake, Antillotyphlops annae. Saint Barthelemy, Lesser Antilles.

Coastal dwarf blindsnake, Antillotyphlops hypomethes. Fort Buchanan, Guaynabo, north-eastern Puerto Rico.

Virgin Gorda blindsnake, Antillotyphlops naugus. Gorda Peak National Park, central Virgin Gorda, British Virgin Islands.

Grenadian blindsnake, Amerotyphlops tasymicris. Union Island, Saint Vincent and the Grenadines, Lesser Antilles.
This is the only West Indian member of its genus, otherwise extended through much of the continental Neotropics.

This group contains all the other living snakes. It is a much more varied group than the previous one and includes the species most familiar to man.

One of the more primitive families of snakes, Boidae, includes quite a number of Antillean representatives. Primitive they might be, but boids include some of the most impressive reptiles alive today. These include the giant serpents of the Americas: the neotropical boa (Boa constrictor) which may reach more than four meters in length, and the four species of anacondas to include the green anaconda, Eunectes murinus, which may reach six meters in length and 98 kilograms in weight. All are South American, although other Boa reach Central America, its islands, and the Lesser Antilles. The largest known snake was an awesome, 12 meter-long monster that also belonged to this group: Titanoboa cerrejonensis.

Together with the members of their related family, the pythons, boas are the constrictors par excellence. Although a few other snakes also rely on this method of subduing their prey, boas are extremely powerful, and have perfected this means of killing like no other group of ophidians.

Boids are ambush predators that will most often allow their victims to come close to them, instead of offering pursuit. A boa intent on feeding constitutes a spectacle worth observing. The seemingly phlegmatic reptile will suddenly explode into an attack, seizing the prey with its fangs and immediately throwing several coils of its muscular body around it. Death occurs by suffocation, since every time the prey exhales the snake will tighten its hold even more, until the ribcage of the victim simply collapses. While most boids feed on rodents and birds, the largest anacondas and neotropical boas can kill and swallow caimans, jaguars, and deer.

A neaonate Greater Puerto Rican boa (Chilabothrus inornatus), shows the umbilical chord that attaches to the rudimentary placenta of the mother.
Guaynabo, north-eastern Puerto Rico.

They also have vestigial hind-limbs, externally seen only as a claw on each side of the vent. Those of males are better developed, and are used to scratch the sides of the females during courtship.

West Indian members of the family belong to three genera: the aforementioned Boa as well as Chilabothrus and Corallus. Like all boids, they are mainly nocturnal creatures with elliptical pupils.

The Lesser Antillean populations of Boa and the Corallus tree boas invaded the region from South America. On the other hand, Chilabothrus is Greater Antillean and Bahamian and, as a group, probably evolved in situ from a Central American stock.

Boa is represented in the region by two endemic species. B. orophias lives in Saint Lucia, while B. nebulosa inhabits Dominica. They seldom reach over two meters in length but they are bulky and heavy for their length. Additionally, the Mexican and Central American subspecies of Boa constrictor, B. c. imperator, is found in a few Caribbean islands east of Central America. There are fossil records of Boa from elsewhere in the Lesser Antillean island chain, as far north as Antigua. It is not known at the moment why those populations became extinct, seemingly in pre-Columbian times.

In my opinion - and course anyone can disagree with me - the genus Boa contains the most majestic and elegant ophidians on Earth.

Saint Lucian boa, Boa orophias. Anse la Raye, western Saint Lucia, Lesser Antilles.

Dominican boa, Boa nebulosa, juvenile. Canefield, western Dominica.
(Photograph courtesy of Mr. Joseph Burgess).

The genus Chilabothrus is endemic to the Caribbean islands and contains 12 known species. Some of them are the largest ophidians in the region, and are the subject of several local legends and superstitions. These snakes are often the biggest predators in many of the areas they inhabit.

A female Cuban boa, Chilabothrus angulifer. Desenbarco del Gramna National Park, Cuba.

This species is the largest of its genus, and perhaps among West Indian snakes.
(Photograph courtesy of Dr. Rosendo Martínez).

First photograph: Los Haitises National Park, northern Dominican Republic, Hispaniola. (Courtesy of Mr. Pedro Genaro Rodriguez).

Last two photographs: Laguna de Nisibon, eastern Dominican Republic, Hispaniola. (Courtesy of Mr. Jorge Luis Brocca).

Chilabothrus striatus ailurus. Cat Island, The Bahamas.
(Photograph courtesy of Mr. Joseph Burgess).

Greater Puerto Rican boa, juvenile sleeping on a branch during the day. El Rosario, south-western Puerto Rico.
This snake finds itself equally at home on the ground as well as in trees.
Its usual diet is based on rodents, birds, and bats. Neonates and small juveniles feed mostly on anoles and other lizards.
Large individuals sometimes enter farms in search of rabbits, cats, and domestic fowl, and sometimes even the agile mongoose falls prey to it (which makes me very happy).
Formerly believed to be very rare, it is now known that in spite of routine killings by humans this boid is rather common even in some sub-urban areas.

A male greater Puerto Rican boa (darker individual) entices a feamle to mate by gently rubbing its cheeks againt hers.

Like other Chilabothrus boas in the Greater Antilles, the Jamaican species sometimes waits by the entrance to caverns in order to capture emerging bats at evening.
Windsor, north-central Jamaica.

All Chilabothrus boas have a peculiar iridescence to their skin. This is a phenomenon resulting from the molecular structure of the upper layers of skin cells (and in such way similar to that of a hummingbird's feathers), and is thus unrelated to the actual pigment of their scales. Even melanistic individuals exhibit beautiful green and blue sheens when they are seen under direct sunlight, especially shortly after a molt.

As with anoles, West Indian Chilabothrus boas can be divided into ecomorphs. However, the concept, as applied here, differs somewhat from the phenomenon seen in anoles. In Chilabothrus, the several island species are vicars of one another, having evolved one from another or all from a common ancestor, after a dispersal event. In anoline ecomorphs the species arose independently, and equivalent species are usually unrelated.

The four large Greater Antillean species of Chilabothrus - the Cuban C. angulifer, the Hispaniolan and Bahamian C. , the Jamaican C. subflavus, and the Puerto Rican C. inornatus - are ecomorphic generalists, being terrestrial and semiarboreal. (The mainland neotropical rainbow boa, C. cenchria, probably belongs to this ecomorph, as well). All reach more than two meters in length, and sometimes three or more. In fact, the largest West Indian snake is Cuban: the "majá de Santa María", Chilabothrus angulifer, which may attain an impressive four meters in length.

Juveniles feed mainly on exotherms, especially lizards. As adults, they feed on endotherms, mostly rodents and birds. The Cuban, Jamaican, and the larger of the two Puerto Rican species prey heavily on bats. They can be seen in groups at night, hanging head-down from lianas and rocky ledges by the entrance to certain caverns, where they capture and devour bats that fly within their reach.

Greater Hispaniolan boa (nominate race, Chilabothrus ) juvenile, devouring an Anolis cybotes cybotes.

Greater Puerto Rican boas, Chilabothrus inornatus, hang from lianas, branches and ledges by the entrance to caverns where bats roost.

They will then strike at bats that fly near them. The method is not very efficient, and many attacks are needed before the reptiles catch their dinner.

The second individual shown constricts an Antillean ghost-faced bat, Mormoops blainvillii.

Conception Island boas, Chilabothrus argentum. Conception Island, The Bahamas.
(Photographs courtesy of Mr. Joseph Burgess).

Then come the four small, strongly arboreal species of Hispaniola and Puerto Rico. E. fordii and E. gracilis are denizens of the arid regions of Hispaniola, while E. monensis is found in Mona Island, and E. granti inhabits littoral areas of the Puerto Rican bank. These species feed mainly on exotherms, especially lizards, although they will sometimes devour small birds and mice. Like the larger and merely semi-arboreal species, these snakes have short and muscular tails which are strongly prehensile and help them maneuver along the branches of trees.

Hispaniolan desert boa (nominate race, Chilabothrus fordi fordii). First three photoghraphs, Matadero de Honduras, southern Dominican Republic, Hispaniola.

(First two photographs courtesy of Mr. Miguel Angel Landestoy. Third photograph courtesy of Mr. Pedro Genaro Rodriguez).
(Last photograph: near Cabral, south-western Dominican Republic, Hispaniola. Courtesy of Dr. Richard C. West).

Finally, the the two small, mainly terrestrial species of The Bahamas, E. exsul and E. chrysogaster, are ecomorphically generalized, and feed on a variety of prey, both exotherms and endotherms.

Southern Bahamian boas, Chilabothrus chrysogaster, spotted and striped morphs, and neonate.

Southern Bahamian boa (Great Inaguan race, Chilabothrus chrysogaster relicquus).

In several species of Chilabothrus, as with many other reptiles, neonates are strikingly different from adults in their colors. As the animals mature, they frequently become darker and less boldly patterned.

Until recently, the two Lesser Antillean populations of Corallus where thought to be conspecific with the South American common tree boa, C. hortulanus. Presently, they are considered endemic species in their respective insular banks. Corallus grenadensis occupies the Grenadian bank, while Corallus cooki is found in Saint Vincent. Corallus are rather slender boas, with laterally compressed bodies and large heads with huge eyes. All members of the genus are highly arboreal in habits, including the beautiful South American emerald tree boa, Corallus caninus. Altogether, the genus comprises eight recognized species.

Saint Vincent's boas, Corallus cooki. Kingstown Botanical Garden, south-western Saint Vincent, Saint Vincent and the Grenadines, Lesser Antilles.

First two photographs: Layou Valley, south-western Saint Vincent, Saint Vincent and the Grenadines, Lesser Antilles.

Last two photographs: Kingstown Botanical Garden, south-western Saint Vincent, Saint Vincent and the Grenadines, Lesser Antilles.

Grenadian tree boas, Corallus grenadensis. Union, Saint Vincent and the Grenadines, Lesser Antilles
(Photographs courtesy of Mr. Mel Jose Rivera).

Corallus boas feed mainly on birds, though Antillean populations rely heavily on reptiles and rodents. Members of this genus have specialized thermoreceptive pits on their lips that allow them to "see" the infrared radiation of homeothermic prey, thus making it easier for them to hunt in the dark. (Boa and Chilabothrus lack this trait). The two Lesser Antillean species are widespread and rather versatile in the habitat requirements, but seem to be especially partial to lowland habitats like mangrove swamps. During the day they sleep neatly coiled around a rather thin branch, sometimes in quite exposed situations.

Corallus cooki, juvenile. Kingstown Botanical Garden, south-western Saint Vincent, Saint Vincent and the Grenadines, Lesser Antilles.

Close-up of the head of a Saint Vincent's boa. You can see the thermoreceptive pits on the upper and lower lips.

Layou Valley, south-western Saint Vincent, Saint Vincent and the Grenadines, Lesser Antilles.

This American family is the largest in the West Indian region. It includes species that occupy several different ecological niches, although most of them are rather unspecialized ground dwellers. A few members of the family have taken to a life in trees. By far, most belong to the subfamily Xenodontinae. All of these are opistoglyph, mildly to moderately venomous snakes that feed mainly on exothermic prey.

Anguillan bank racer, Alsophis rijgersmaei, female. Morne de Grand-Fond. Saint Bartholomew, Lesser Antilles.

The main group of these, as represented in the West Indian region are those of the tribe Alsophiini: the Antillean racers and treesnakes.

In a manner somewhat similar to that of sympatric anoline ecomorphs, Antillean alsophines exist in more or less parallel arrays of species in some of the islands. In most Antillean forests there is one or two species of medium- to large-sized, mainly terrestrial snakes (Alsophis, Borikenophis, Caraiba, Cubophis, Haitiophis, Hysirhynchus, etc.). These snakes are usually alert predators that either pursue their prey or lie in wait for them, above ground or on tree branches. Additionally, and particularly in the Greater Antillean insular banks, there are always several medium to small-sized terrestrial species of the same tribe (Arrhyton, Ialtris, Magliophis, some other Hysirhynchus). Some of these species are cryptozoic, staying most of their time under rotten logs, rocks, and leaf litter. Borikenophis racers will often take to the trees, and Hispaniola's Uromacer snakes are definite arboreal in their habits. Sadly, a number of species and populations have been driven to extinction by the introduced Indian mongoose and, to a lesser degree, by feral cats.

Members of several of these genera (Alsophis, Cubophis, Borikenophis, Haitiophis, Hypsirhynchus, and Magliophis) exhibit the interesting defensive display of extending their throats like a hood in a manner similar to a cobra's. The hood is not as well developed as i the latter case, but it is still alarming enough to some potential predatorsa and people. The venom of Cubophis cantherigeus from Cuba and Borikenophis portoricensis from Puerto Rico is capable of sending a careless human to the hospital for a few days. However, fatalities are unknown.

A female Puerto Rican racer (nominate race, Borikenophis portoricensis prymnus) raises its head and flattens its throat in a threat.

Some species also has the habit of staying coiled and motionless, while waving the tip of the tail in resemblance to a worm. In such way it attracts anoles within striking distance. However, the ruse sometimes backfires when it attracts some large bird, instead. Due to that, a good number of adult individuals are found missing the tips of their tails.

Last photograph: female.
Slopes of Mount Scenery, central Saba, Lesser Antilles.
In spite of its rather large size, this is a very placid snake that almost never attempts to bite when handled.

Orange-bellied racer, Alsophis rufiventris, female. The Quill National Park, southern Saint Eustatius, Lesser Antilles.
The species exhibits a slight sexual dichromatism, with females being duller in their colors.

A male orange-bellied racer, Alsophis rufiventris, stalks its prey under the leaf litter. The Quill National Park, southern Saint Eustatius, Lesser Antilles.

This is one of the World's rarest snakes, almost driven to extinction by introduced rats and mongooses.

Unusual among Antillean dipsadids, the two genders of Alsophis antiguae exhibit sexual dichromatism.

Dominican racers, Alsophis sibonius, male (dark brown) and a female (reddish).

Anguillan bank racer, Alsophis rijersmai, juvenile female. Petite Saline, Saint Bartholomew, Lesser Antilles.

Anguillan bank racer, Alsophis rijersmai, male (grayish) and female (brownish). Morne Rouge, Saint Bartholomew, Lesser Antilles.

Cuban racers, (nominate race, Cubophis cantherigerus cantherigerus). Guanahacabibes Peninsula, western Cuba.

First photograph: female. Next two photographs: male devouring a Cuban treefrog, Osteopilus septentrionalis.
(Photographs courtesy of Mr. Joseph Burgess).

Grand Cayman racer, Cubophis caymanus. Queen Elizabeth II Botanic Park, central Grand Cayman.
(Photographs courtesy or Mr. Marcos J. Rodriguez).

Bahamian racers (nominate race, Cubophis vudii vudii).
First photograph: southern Andros Island, The Bahamas.
Second photograph, Eleuthera, The Bahamas.

Next two photographs: Loma Charco Azul Biological Reserve, Puerto Escondido, south-western Dominican Republic, Hispaniola.

This is the largest non-boid snake in the Caribbean.
(Photographs courtesy of Mr. Miguel Angel Landestoy).

Puerto Rican racers (northern Puerto Rican race, Borikenophis portoricensis portoricensis).
First photograph: male. Cambalache State Forest, north-western Puerto Rico.
Second photograph: female. Fort Buchanan, Guaynabo, north-eastern Puerto Rico.
This race inhabits most of that island, except for the extreme arid south-west, which is occupied by A. p. prymnus.
Since this species seems to be more arboreal than its congeners it has avoided been extirpated by mongooses, at least in mainland Puerto Rico.

All the same, it is rare in many areas, due to predation by exotic predators. This snake preys mostly on lizards (anoles,
ameivas, geckoes) but will also feed on frogs, birds, small mammals, and other snakes.

Reddish morph of Borikenophis portoricensis portoricensis, female. Toa Baja, north-eastern Puerto Rico.

Puerto Rican racers are rather drab in their colors, but many individuals have varying amounts of yellow or greenish on their bodies.

This is a male Borikenophis portoricensis portoricensis from Quebradillas, north-western Puerto Rico.

A mating pair of Borikenophis portoricensis portoricensis, and one of the resulting hatchlings.
Captive specimens from Guaynabo, north-eastern Puerto Rico.

Puerto Rican racer, (British Virgin Islands race, Borikenophis portoricensis anegadae), male. Mount Sage, west-central Tortola, British Virgin Islands.

The species has been extirpated from many of the smaller Puerto Rican bank islands where mongooses have been introduced.

A juvenile Borikenophis portoricensis anegadae freezes in place at my approach.

Indeed it looks like one of the roots that are common in the substrate where it usually prowls.

Last photograph: female; Caja de Muerto Nature Reserve, off southern Puerto Rico.

Borikenophis portoricensis prymnus, juvenile. Guanica State Forest, south-western Puerto Rico.

Neonates and juveniles of this species are usually lighter and more brilliantly colored than adults.

Puerto Rican racer (United States Virgin Islands race, Borikenophis portoricensis richardi), female and juvenile. Culebra Island, off eastern Puerto Rico.

Monan racer, Borikenophis variegatus, juvenile. Playa Pajaros, south-eastern Mona Island.
(Photograph courtesy of Mr. Mel Jose Rivera).

Among Caribbean snakes, larger alsophines are notoriously fast snakes with excellent sight. Often, one merely catches a glimpse of "something" as the animal quickly disappears into the tall grass or underbrush. For all their agility, being diurnal snakes that often prowl in the open, they are frequently preyed upon by other sharp-eyed predators. Hawks and other raptorial birds are sometimes seen flying with one of them in their talons.

Alsophine snakes have excellent eyesight, tuned to detect the movements of their prey.

Puerto Rican racer, (nominate race, Borikenophis portoricensis portoricensis), female.

The genus Hypsirhynchus is distributed between Hispaniola and Jamaica. Two Hispaniolan species are called "hognosed racers", for their upturned snouts. Like their relatives, all these are quick, high-strung snakes that feed mostly on lizards. They possess elliptical pupils that point to their partially nocturnal or crepuscular habits. That trait, together with their flattened and somewhat triangular heads, gives them the appearance of vipers. Other species of the genus are more typical in their appearance but are likewise seldom found in open areas. Most spend their time under rocks and debris.

Jamaican black racerlet, Hypsirhynchus funereus, female. Windsor, north-central Jamaica.

The region's smaller xenodontines, like Arrhyton, Magliophis, and Ialtris feed on small lizards and frogs (and their eggs) and on some invertebrates, which they subdue with their weak venoms. Even where they are common, some species are infrequently observed because the spend most of their time under rocks and debris.

Then we have the three species of Uromacer. These are arboreal snakes endemic to Hispaniola, and ecologically are similar to the vine snakes (Oxybelis) of Central America. They might be the most specialized West Indian snakes save for typhlopids and leptotyphlopids.

Tan, brown, or green in color, Hispaniolan treesnakes wait in ambush for their prey: anoles, geckoes, and small frogs. They mimic thin branches and lianas so well that, even where common, they are very difficult to notice unless they move.

In the Lesser Antilles are found several species of groundsnakes of the genus Erythrolamprus. These are similar in appearance to the alsophine racers and fill similar niches, but belong to a different xenodontine radiation. Like alsophines, they feed mostly on small exothermic prey. They sometimes have shorter snouts which, together with their large eyes, give them a strangely "babyish" appearance.

Erythrolamprus groundsnakes are almost exclusively terrestrial, and since they are not as fast and agile as alsophines they are more vulnerable to predation by mongooses and cats. Indeed, populations in islands like Saint Lucia, Grenada, and Barbados have been decimated by exotic vermin.

The first two photographs show a striped morph male. Eggleston, south-central Dominica, Lesser Antilles.

The third photograph shows a spotted morph female. Cabrits National Park, north-western Dominica, Lesser Antilles.

Saint Lucian groundsnakes, Erythrolamprus ornatus. Maria Major Island, off south-eastern Saint Lucia, Lesser Antilles.
First photograph: male. Last two photographs, female.
This is one of the most endangered reptiles on Earth. Extirpated from mainland Saint Lucia by the mongoose, it survives solely on the tiny Maria Islands Nature Reserve.

The small Tretanorhinus variabilis, found in Cuba and the Cayman Islands, is unique among endemic Antillean xenodontines in being semi-aquatic in habits. It belongs to the subfamily Dipsadinae.

The colubrids are the largest ophidian family in the World, inhabiting every continent (except Antarctica) as well as many oceanic islands. They are rather scantily represented in the region, being found here only so far north as some of the Lesser Antilles. The ancestors of Antillean species invaded the islands from South America.

In Saint Vincent and Grenada, Mastigodryas bruesi partially fills the large alsophine niche of other Caribbean islands. With excellent eyesight and able to climb trees with ease, these agile snake is, all the same, endangered due to the presence of mongooses. Like their Alsophis ecologic counterparts, they are very fast and feed mainly on frogs and lizards. Their large eyes are a testimony to their visual acuity.

Windward tree racer, Mastigodryas bruesi, female. Saint George's, south-western Grenada, Lesser Antilles.

Endemic to the insular banks of Saint Vincent and Grenada, this fast snake can be found both on the ground and on trees.

Members of this group are usually associated with water. Some exhibit an irascible disposition, and bite readily when threatened. However, although their sharph teeth can inflict cuts on a human hand, they are all otherwise harmless to people.

Cuba is inhabited by a subspecies of Nerodia clarkii. Uniquely, this is a North American reptile that has invaded the West Indian region through natural means.

Vipers in general have the most elaborated venom-injecting apparatus among ophidians. Their fangs are hinged to the maxilla, and rotate forward and down as the reptile opens its mouth to strike. The venom itself is usually a mixture of protease enzymes that begins to digest the prey from the inside out even before it is swallowed. The nature of the proteolytic viper venom causes a bite to be extremely painful, at times.

These are among the most advanced snakes on Earth, and the more advanced of viperids belong to the subfamily Crotalinae: the pit vipers. They are represented by two species in the Lesser Antilles, Bothrops caribbaeus being endemic to Saint Lucia and B. lanceolatus to Martinique.

Pit vipers are named thus due to the presence of two cavities, one behind each nostril, which function as thermal receptors. These are analogous to those of of the Corallus tree boas mentioned above, yet are even more efficient. The thermal pits of some of these snakes are so sensitive that they can detect a variation of about 0.01 degree Celsius in their near surroundings.

Bothrops snakes feed mostly on small endotherms like mice and rats, although a bird or lizard may also warrant their attention. The snake usually bites its prey with a lighting-fast attack and immediately releases it. In fact, the reptile inflicts little more than a double stab into the flesh of its victim. With its keen sense of smell it then follows the scent trail of the wounded animal as it wanders away to die a few seconds or minutes later. Once the dead prey is located the snake will swallow it head first, in typical ophidian fashion.

Both Caribbean species are mainly terrestrial and nocturnal, seeking refuge during then day under logs, rocks, and even piles of garbage where rats will often congregate in search of food scraps. Although shy in habits, their venom can be extremely virulent to humans though only few fatalities are known. Aside from crocodiles and coral snakes, these are the only truly dangerous reptiles in the Caribbean islands.

Saint Lucian viper, Bothrops caribbaeus, juvenile. Troumassee Bay, south eastern Saint Lucia.
The second photograph clearly shows the thermoreceptive organ that gives the entire subfamily its name.

Aside from the Bothrops pit-vipers, the elapids are the only other seriously dangerous poisonous ophidian group that exists in the West Indies. These snake are widely distributed around the World, in Asia, Africa, Australia, North, Central and South America. Some of the deadliest snakes on earth belong to this group of proteroglyph snakes, including cobras, mambas, tiger snakes, taipans, kraits, and coral snakes.

The single West Indian elapid is a species of Micrurus coral snake, found in New Providence island off the coast of Mesoamerica and shared with the nearby continental lands.

Members of this family are commonly known as "dwarf boas" in spite of the fact that they are not boids, at all. The group is Neotropical, and the genus Tropidophis (the "tropes") is mainly Antillean. In this region, they are found in Cuba, Hispaniola, Jamaica, and the Cayman Islands. These are small to medium-sized, mostly cryptozoic snakes, some with beautiful and striking color patterns. When they feel threatened, some species have the strange defensive habit of bleeding from their mouths. They may also coil into a tight ball, in order to protect their heads.

A Jamaican eyespot trope, Tropidophis stejnegeri, bleeds from its gums upon being handled. Sheffield, western Jamaica.

Hispaniolan trope (natural intergrade, Tropidophis haetianus haetianus and T. h. tiburonensis).
First two photographs: male. Rabo de Gato, south-central Dominican Republic, Hispaniola.
Last two photographs: female. San Rafael, southern Dominican Republic, Hispaniola.

Hispaniolan trope, south-eastern race, Tropidophis haetianus hemerus, juvenile. Near La Romana, south-eastern Dominican Republic, Hispaniola.

Inaguan trope, Tropidophis canus. Great Inagua, The Bahamas.
(Photographs courtesy of Mr. Joseph Burgess).

Jamaican eyespot tropes, Tropidophis stejnegeri.
First two photographs: Sheffield, western Jamaica.
Third photograph: Hellshire Hills, south-eastern Jamaica.
Last photograph: Near Quickstep, north-central Jamaica.

Caicos trope, Tropidophis greenwayi, captive specimen. Big Ambergris Cay, Turks and Caicos.

Giant trope, (nominate race, Tropidophis melanurus melanurus).
First two photographs: Guantanamo United States Naval Base, Guantanamo, south-eastern Cuba.
Third photograph: Guanahacabibes Peninsula, western Cuba.

Giant tropes, (nominate race, Tropidophis melanurus melanurus). Cabo Cruz, Granma Province, south-eastern Cuba.