The reptiles on Saint Martin could be grouped into several categories: common and frequently seen, common but rarely seen, recently introduced, and probably extinct. More scientifically, including species that are possibly extinct here, there are eleven species of lizard, two snakes and one tortoise. This guide covers the ten species that I have seen and photographed.
The turnip-tailed gecko (Thecadactylus rapicauda) is cited in some literature as present on Saint Martin, although I have not seen it. It can be distinguished from the house gecko by its bulbous tail. The two-striped mabuya (Mabuya bistriata) is a skink that is cited as probably exterminated on the island. It is somewhat similar in appearance to Amieva plei, although it is shinier, moves in a smoother fashion and does not get as large.
The Lesser Antillean iguana (Iguana delicatissima) has been cited as probably exterminated from the island, although small populations still exist on other nearby islands. It is smaller than the common iguana (Iguana iguana), and lacks the large subtympanic scale present in that species. I have heard that some individuals may have been reintroduced, although interbreeding with the more common Iguana iguana makes it relatively unlikely that pure stock would remain on the island for very long.
The leeward island racer (Alsophis rijersmai), the only native snake on the island, is at best very rare. In fact, as early as the 1950s it was though to be eradicated, but specimens were seen in the 1990s. Apparently it is relatively common on Anguilla and St. Barths where there are no mongoose populations.
Anguilla Bank Anole (Anolis gingivinus)
Exceedingly common on St. Martin, Anguilla and St. Barths, this is one of many species historically considered part of the bimaculatus group of anoles found in the northern Lesser Antilles through Dominica and shares some characteristics with anoles of the Greater Antilles. Recent genetic analysis of these species indicates that the relationships between these species are more complicated than expected, and that A. gingivinus is a sister species to A. bimaculatus, which is found in St. Eustatius, St. Kitts and Nevis.
The Anguilla bank anole is the larger of the two anole species present on St. Martin and may be up to seven centimeters in snout-to-vent length (SVL), which basically means not counting the tail. It generally prefers sunny elevated perches, and is often seen on tree trunks or branches. It has white bands on either side of the belly and an irregular band across the top, although the dorsal band may be obscured by spots or mottling, particularly in males. The coloration varies from light tan to brown to green with an off-white belly. The dewlap is orange with white spots.
This anole is found essentially throughout the island. In relatively open areas it is much more common than the bearded anole (Anolis pogus), while in forested areas it is less common. It has been suggested that it is less common at higher altitudes, but I believe this is simply because that is where most of the dense forest still exists. Even atop Pic Paradis, the highest point on the island, Anolis gingivinus is very common in open areas.
When fighting over territory, males change color dramatically, developing a dark patch behind the eye and accentuating their spots. They can also raise a large crest down their back that is not normally there. Other color variations seem to be related primarily to camouflage.
Bearded Anole (Anolis pogus)
This anole is found only on St. Martin, although it once was also present on Anguilla and perhaps St. Barths. Until 1990, it was considered a subspecies of Anolis wattsi. Current species formerly grouped under A. wattsi include A. wattsi, which is native to Antigua and introduced to St. Lucia, Trinidad and Tobago, A. forresti, found on Barbuda and A. schwartzi, found on St. Eustatius, St. Kitts and Nevis. A. schwartzi and A. forresti are still considered subspecies of A. wattsi by some. The four species are very similar in appearance, and occupy analogous niches on their respective islands.
It is slightly smaller than the Anguilla bank anole, reaching a maximum SVL of about six centimeters. As it prefers shady areas, it most common on the forested hills and mountains, but can be found at sea level and even in developed areas if there is appropriate habitat. It is primarily seen on the ground or perched in the undergrowth or lower branches.
Coloration of this anole is highly variable. To some degree, the easiest way to identify it is by the lack of white bands on the sides. One common color pattern is tan with a turquoise patch around the eye. Darker brown and gray are also common, sometimes with light orange patches or bands. There may be a narrow, light dorsal stripe and irregular darker bands across the back, and these patterns vary from almost unnoticeable to very pronounced. The top of the head may be rust colored as well. In some cases the eye may be circled by red instead of turquoise, and when males are fighting for territory they may develop two black spots behind their eye. Like Anolis gingivinus, they are also capable of raising a crest down their back that is not normally present.
Common Iguana (Iguana iguana)
The common, or green iguana is currently very common on St. Martin, but this was not always the case. Habitat destruction, mongoose predation and human consumption contributed to the extinction or near-extinction of this species on the island by the early 1990s. Since then, particularly in the last few years, they have either rebounded or re-colonized the island.
It is possible that escaped pets are the progenitors of the new population. Also, after hurricanes in 1995, a group of 15 iguanas adrift on a tangle of trees made an improbable overseas journey over 200 miles from Guadeloupe to Anguilla, where they were previously not found. At the time, this was the most extreme example of colonization by long distance rafting documented by scientists. It also seems possible that re-colonization of Saint Martin may have happened by natural means as well.
The green iguana is easily distinguished from its smaller cousin, Iguana delicatissima, by the presence of a large subtympanic scale. This is a round scale found below the lower jaw and is present on both juveniles and adults. While young specimens are bright green, this coloration gives way to primarily brown coloration as the iguanas mature. Some specimens may also be reddish-orange or nearly black. Banding down the back and black rings around the tail are also typical of the species.
This species is most common in wetland areas, often roosting in mangroves at the edge of salt ponds. When approached, they frequently run directly into the water. I have seen them descend and either not surface for several minutes, or swim underwater to surface unseen in a mangrove thicket. I have also seen them swim across salt ponds at the surface. In the late afternoon, they may often be seen sunning themselves on rocks or even seaside cliff faces.
Anguilla Bank Amieva (Amieva plei analifera)
Teiids from the genus Amieva are found on most of the islands in the Lesser Antilles. The species found on Saint Martin, Amieva plei, is also found on Anguilla and St. Barths, although the subspecies analifera is endemic to Saint Martin.
These ground-dwelling lizards are often quite large and, while fast, have an ungainly gait, skittering from side to side. Juveniles are typically brown with light stripes on the back running from behind the head to the hind legs. Both adults and juveniles typically have light spots from their hips down their tails. Some individuals have a greenish tint in the lower part of their body. Very large adults sometimes have black patches or bars on their shoulders, a characteristic that is only found in the Saint Martin subspecies.
These sun-loving lizards are often found on roadsides where they forage for insects and other invertebrates in the leaf litter. In some areas they may also be found at the edge of the beach. While they are often present in partially-forested areas, it is unusual to see them in dense forest.
While these lizards seem very common, because they are highly visible near human habitation, it is believed that their numbers are significantly suppressed by mongoose predation. On mongoose-free islands, Amieva are widespread, while on islands with mongoose populations, they tend to be restricted to developed areas that are avoided by mongoose. To some degree, it is possible that the continued development of Saint Martin offer some benefits to this lizard, but mongoose eradication would clearly be the preferred method for ensuring its survival.
Dwarf Gecko (Sphaerodactylus parvus)
This diminutive gecko was considered a subspecies of Sphaerodactylus macrolepis until 2001, when it was elevated to species status. It is found only on the islands of the Anguilla Bank: Anguilla, St. Martin and St. Barths. To my knowledge, there is no common name for this species.
Parvus is slightly smaller than Sphaerodactylus sputator, reaching a maximum SVL of about 3.5 cm. They are typically a medium brown with scattered dark spots on the back. Just behind the head, there is a distinctive dark oval with two light spots and usually a light ring around it. The head often has a pattern of dark bands. For a gecko, the head is quite narrow and the eyes are quite small.
This gecko is typically found in leaf litter in forested parts of the island. A very observant hiker may notice these occasionally, but they are easiest to find by lifting stones or pieces of log from the forest floor to uncover them (and replacing them gently afterwards). I have found that geckos seem to be more common beneath wood and lighter stones where there is decomposing leaf litter and abundant invertebrate life. Heavier stones sunk into the soil do not seem to be popular.
They can also be found around human habitation, typically beneath boards or stones in shady areas. Very small eggs, a half-centimeter or less in length, may also be found beneath stones in areas where these geckos live, although I don’t know of any way to distinguish between the eggs of sputator and parvus without waiting for them to hatch.
Parvus coexists with sputator, and I have not discerned any difference in habits or preferred habitat. On the satellite islet Pinel, they are both quite common in the very limited amount of suitable habitat that exists.
Least Island Gecko (Sphaerodactylus sputator)
Sphaerodactylus sputator can be found on a half dozen islands, including Sombrero, Anguilla, St. Martin, St. Barths, St. Eustatius, St. Kitts and Nevis.
Typical coloration is grey with broken white stripes and dark bands on the back. An orangish tail and bronze iris are cited as characteristics that are specific to the population on St. Martin. Close inspection may reveal occasional raised red scales scattered around the body. This species has a very typical gecko shape, with very large eyes and a broad head.
Darker individuals may be confused with S. parvus, but the size of the eyes and shape of the head can aid with identification. Females may reach nearly four cm in SVL, slightly larger than S. parvus, but the difference is not noticeable unless one was to measure them, which would be challenging.
In my observation, the habits and preferred habitats of the two species of dwarf gecko are indistinguishable. S. sputator more closely resembles other dwarf geckos in the Lesser Antilles, while S. parvus is closely related to S. macrolepis which is present in Puerto Rico and Central America. This may indicate that the two species arrived at different times or from different directions. Despite being the same size and sharing the same habitat, populations of the two species seem to be entirely distinct, suggesting that interbreeding is impossible.
Tropical House Gecko (Hemidactylus mabouya)
This medium-sized gecko (up to 7 cm in SVL) is native to sub-Saharan Africa, but now lives in tropical areas of North, Central and South America as well as most islands in the Caribbean. It was likely introduced to the Americas inadvertently.
Coloration can vary dramatically, from very pale or pinkish with few visible markings to a mottled grey or brown coloration. It is often seen at night in or around homes and other buildings, but can also be found under boards or rocks in some grassy areas. Eggs are typically laid in pairs in rotting wood or beneath stones.
Like other geckos, minute setae (hair-like bristles) on their toe pads give them the ability to easily climb vertical surfaces. This gecko also has the ability to spontaneously drop its tail when frightened to distract predators.
While these insectivores are welcome guests in many homes, it is unknown what negative impact they may have on native species.
Locally geckos are often called woodslaves. Their climbing abilities have inspired a local legend that if you get one on your skin you need to use a hot iron to remove it because it will stick too strongly to remove it otherwise.
Underwood’s Spectacled Tegu (Gymnophthalmus underwoodi)
This lizard is a microteiid, and is similar in size to the dwarf geckos. Its previously described range includes parts of Central and South America as well as a number of islands in the Lesser Antilles, although none particularly near St. Martin. I would guess that it is a relatively recent introduction to St. Martin, done inadvertently by man.
These lizards have a shiny tan back with darker sides and an elongated body shape with a very long tail. It could be possible to confuse them with a young skink (if there are any on the island) or ground lizard, but I think it is unlikely. If in doubt, identification may be confirmed by the presence of only four toes on the front feet.
Typical habitats for these lizards are sunny grassland areas or scrublands. They may be seen beneath rotting logs in open areas, but they also forage openly in the grass. Due to their small size they may easily be overlooked.
This curious lizard is unisexual and reproduces parthenogenically. This may be a key factor in its ability to colonize new islands, as a single individual can reproduce to start a new population.
This lizard is named after Garth Underwood, a pioneering British herpetologist responsible for much important work on reptiles in the Caribbean, including significant revisions to the taxonomy of Anolis species of the Lesser Antilles in the late 1950s.
A related species, Gymnophthalmus pleei, is found on some of the Lesser Antilles and is quite similar in appearance, but is not known to reside on St. Martin. It has ridged scales on the tail, which offer a subtle point of differentiation. As its range includes other French West Indies (Martinique and Guadeloupe), it would not be too surprising for G. pleei to arrive in the future as an accidental introduction.
Brahminy Blind Snake (Ramphotyphlops braminus)
This strange-looking snake is native to Africa and Asia, but has been introduced to many areas around the world. Sometimes called the flowerpot snake, it is thought that this species has been introduced in part through stowaways traveling in potted tropical plants. It is probably introduced to Saint Martin only recently.
This snake is very small, reaching only about 17 cm in length, and has a worm-like appearance. It is, however, a surprisingly fast mover. Its eyes are rudimentary and are covered with scales, limiting its vision. They seem to sense light and darkness, but probably nothing more than that. The tail is quite short and may be hard to distinguish from the head.
This species is likely to have a limited range, and I have only seen them in Grand Case. They are typically found under stones, bricks or boards, but apparently may be seen in the open after heavy rain. When captured, they thrash violently and excrete a smelly substance from a pair of glands near the base of the tail to discourage predators.
Like Gymnophthalmus underwoodi, this species is parthenogenic, and all specimens collected have been female. Several other species of blind snake are present in the Caribbean, but none are recorded on Saint Martin.
Red-footed Tortoise (Geochelone carbonaria)
This is the only species of tortoise found in the Lesser Antilles. Native to South America, it may have been introduced by Arawak or Caribe settlers as a food source before European colonization, or perhaps later either for food or as escaped pets. This genus also includes the giant tortoises of the Galapagos islands.
This medium-sized tortoise is typically 25 to 35 cm in carapace-length and can easily be identified by the yellow and orange spots in the center of the plates on the back of its shell, as well as the yellow to red scales on its face and limbs. The shell is somewhat rectangular, but mature specimens tend to develop a noticeable “waist” mid-shell which gives them an hourglass appearance.
Their round, brittle eggs, which are laid in small clutches, may be eaten by mongoose and rats. Their natural habitat is ranges from forest to grassland areas, and their diet is omnivorous, including carrion as well as fruits and plants.
This species does not seem to be particularly common. I have seen one individual crossing a path in a scrubby area of Pinel and know that they are present on Goat Mountain. In the past, they were common on Tintamarre as well, but are now thought to be rare there, the majority being taken home for pets, or dinner. There are apparently a great many of these turtles in captivity on the island, and they breed readily in this situation.
In addition to the terrestrial reptile species covered in this volume, four species of sea turtle are known to live in the seas surrounding the island: the green turtle (Chelonia midas), hawksbill (Erytmochelys imbricata), loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea). Only the hawksbill and green turtles are regularly seen when diving or snorkeling, as the loggerhead and leatherback primarily live in the open ocean rather than reefs or sea grass beds. Hawksbill, green and leatherback turtles all nest on the island and nearby islets. Although less common than in the past, tracks and nests can be seen from April through November, particularly on more secluded beaches.