Friday, August 26, 2016

Brown Vine Snake, Oxybelis aeneus (Family Colubridae)

Size: 1010 mm SVL, 1668 mm TL, may reach 2 m; hatchlings 200 mm; tail 54-77% SVL. Identification: A slender, vine snake with a sharply pointed snout, no loreal scale, 17 scale rows at mid-body, reduced to 13 scale rows posteriorly, and a uniform gray-brown dorsal pattern. Other Trinidad and Tobago vine snakes (genus Leptophis) have 15 scale rows at mid-body and a loreal scale and while Imantodes has 17 scale rows at mid-body, it has a blunt head, a blotched pattern and an enlarged row of vertebral scales. Rostral not visible from above; nasals single; one or two preocular; one to three postoculars; 7−9 upper labials,7−9 lower labials; ventrals 179−192; divided cloacal plate; divided subcaudals 171−192 in males 156-181 in females; dorsal scales smooth. Distribution: Widespread in the Neotropics, present on Trinidad and Tobago. Habitat: An arboreal, forest and forest-edge snake that uses scrub and agricultural areas. It sleeps off the ground on the vegetation. Biology: Diurnal. Diet is mostly lizards, but frogs and small birds are also eaten. Reproduction: Clutches of 3–6 eggs are laid in May-June.

False Coral Snake, Oxyrhopus petolarius (Family Dipsadidae)

Size: 725 mm TL, maximum total length about 1.1 m. Identification: Rostral barely visible from above; nasal single; loreal elongate and single; one or two preoculars; two postoculars; 7–8 upper labials; 8–9 lower labials; 199–204 ventrals; cloacal plate single; 81–86 subcaudals. Dorsal scales smooth in 19 rows (occasionally 17) at midbody. Most specimens black with red annuli which do not extend onto the venter, however may be uniform black, may also have crossbars reduced to large spots; venter uniform cream. The only T&T snake with 19 (or 17) rows of smooth dorsal scales, a single cloacal plate, a single nasal, and usually a banded pattern of red and black, but may be entirely black on dorsum. Hatchlings completely red with a black head. Habitat: Forest, savanna, secondary growth. Biology: Nocturnal. Diet includes small mammals, lizards, and snakes. Reproduction: Clutches of 5–10 eggs.

Coffee Snake, Ninia atrata (Family Dipsadidae)

Size: 300 mm SVL, 85 mm tail; may reach 490 mm in total length. Identification: The only Trinidad and Tobago snake with a collar making and uniform blue-black color pattern on the dorsum; the venter is immaculate. The collar may be orange, white, or pink, and it may be absent in some specimens, particularly old adults. Scales are keeled and in 19 rows. Rostral visible from above; nasal single; loreal single; preocular absent (fused with loreal); one postoculars; six or seven upper labials; six or seven lower labials; ventrals 147−158; cloacal plate single; 48−59 paired subcaudals. Distribution: A widespread snake, ranging from Honduras and Costa Rica to Ecuador and Venezuela. It also occurs on Trinidad and Tobago and the species is widespread on both islands. Habitat: Forests, urban gardens from sea level to the highest peaks on the islands. Biology: Nocturnal. Diet includes slugs (gastropods). Predators include coral snakes. Other common names: collared snake, ring neck snake, white-collared snake

Simla Coffee Snake, Ninia franciscoi

A recently described species from the Arima Valley of Trinidad, and known from a single specimen. It is sympatric with Ninia atrata.

Trinidad Ribbon Coral Snake, Micrurus lemniscatus diutius (Family Elapidae)

Size: 1220 mm SVL; 100 mm tail; tail 8-10% SVL in males; 8-9% of SVL in females. Identification: A very distinctive snake with bright, bold colored rings, black bands in groups of three (triad). Snout blunt and rounded; rostral visible from above; nasal divided; loreal absent; six or seven upper labials; six or seven lower labials; one preocular; two postoculars; 226 or fewer ventrals in males; 239 of fewer ventrals in females; and 35−38 paired (usually) subcaudals in males, 32−41 paired subcaudals in females. Dorsal scales are smooth and in 15 rows. Black rings in 7−13 triads, groups of three black rings each separated by a white or yellow ring form a single triad; each triad separated by a wide red ring. Tip of nose black followed by a white preocular ring, followed by a red collar. Red and white scales in this species have black pigment. M. circinalis lacks the triad pattern and has large red rings separated by short black bands; each of these black bands is outlined by a very short white ring.Oxyrhopus petolarius in Trinidad has a black and red pattern without white. The ringed pattern ofHydrops consists of numerous rings of black separated by red or orange rings that are about equal in length. Distinguishing this coral snake from its colubrid mimics (or models), Erythrolamprus aesculapii and E. bizona, at a distance is difficult; Erythrolamprus have a loreal scale, the coral snake lacks it; Erythrolamprus have paired or single black annuli, instead of the triad found in this species. Only two specimens of the mimics have been found on Trinidad, and caution is always the best approach when collecting coral snakes. Distribution: M. l. diutius inhabits Trinidad, eastern Venezuela, and the Guianas and northern Brazil; on Trinidad it is widespread, usually at elevations below 300 m. Habitat: Forests and savannas, frequently in or near bodies of water. Biology: Nocturnal, but may be active on overcast days. Diet: Snakes, lizards, synbranchid eels. Reproduction: A female collected in early July contained two eggs.

Trinidad Coral Snake, Micrurus circinalis (Family Elapidae)

Size: 540 mm TL maximum 800 mm TL. Identification: Head small, about same width as neck; rostral visible from above; nasal divided; one preocular; two postoculars; seven upper labials; seven lower labials; males 174-193 ventrals; females have 194–209 ventrals; cloacal plate divided; males 40–50 subcaudals females with 30–35 subcaudals; smooth dorsal scales in 15 rows. Black rings 21–31; black rings edged with yellow and separated by long red interspaces. Female's tail with 5–8 black rings, male's tail with 8–12 black rings. Tail coloration is predominately black with some narrow white bands separating the black rings. All red and white scales are tipped with black. Distinguished from the other coral snake Micrurus lemniscatus diutius because of the very short white rings, usually less than one mid-dorsal scale in length. The absence of a loreal will readily distinguish it from all the banded colubroid snakes on Trinidad except Hydrops, which has black and red-purple bands of about equal widths. Distribution:Restricted to Trinidad and its satellite islands of Gaspar Grande and Monos; on adjacent mainland Venezuela. Habitat: Forest and savanna; but present in urban habitats. Biology: Nocturnal. Diet includes small fossorial snakes and lizards. Reproduction: Mating reported from January to May, clutches of 2–6 eggs laid from July to September.

Yellow-necked Racer, Mastigodryas amarali (Family Colubridae)

It is unlikely this snake is present on Trinidad or Tobago, but a recent paper suggests that it on both islands. It is included here until the situation can be further investigated.

Leptophis stimsoni (Family Colubridae)

Size. 593 mm SVL, TL 832 mm. Diagnosis. Silver-gray above, tan below, dorsolateral stripe on each side, a dark post ocular stripe, labials white. A small, slender snake with 15 scale rows at mid-body, reduced to 13 rows posteriorly; ventrals number about 147, and subcaudals number about 135. The tail is about 40% of the body length. The coloration, pattern, and lower ventral count will readily distinguish this snake from other Trinidad and Tobago Leptophis. Distribution. Known only from Trinidad’s Northern Range. Life History. Known from only a few specimens, this snake life history remains to be described.

Oliver's Lora, Leptophis coeurleodorsus (Family Colubridae)

Size. 1.2 m. Diagnosis. A thin, bright green snake with a copper colored lateral stripe. Dorsal scales in 15 rows at mid-body, reduced to 13 rows near the vent. Scales on the mid back are slightly larger than lateral scales. It has a dark stripe that passes through the eye, and eight or nine upper labials. Distribution. Northern Venezuela, Isla Margarita, Trinidad, Tobago. Life History. An arboreal, forest, and forest-edge snake that will use agricultural and urban habitats. Diet is mostly frogs and lizards. Clutches of 3–5 eggs have been found in bromeliads high in in the forest canopy of related species. Other common names: parrot snake, green horse whip, machete, and whiplash.

Water Mapapie, Helicops angulatus (Family Dipsadidae)

Other common names: Banded Water Snake; Water Snake, Brown Banded Water Snake.
Size: Males 475 mm, female reach and probably exceed 625 mm; tail 31−43% SVL.
Identification: Head broad, eyes dorsolateral; body stout; dorsum red-brown with 20–27 dark brown cross bands on body and 15–20 blotches on tail; dark blotch on nape may fuse to first cross band. Venter tan or pink with dark brown bands that usually coincide with dorsolateral bands. Rostral visible from above pentagonal; nasal divided and separated by two internasals; prefontals paired; eyes small and directed more dorsally; loreal single and in contact with the second and third labials; one preocular; two postoculars; two primary temporals and three secondary temporals; 7–9 upper labials, sixth largest, and fourth enters the orbit; 7–10 lower labials; anterior chin shields longer than the second pair and the anterior pair contacts the first five lower labials; 114–121 ventrals; anal plate divided; 63–72 paired subcaudals. Keeled, striated and elongated dorsal scales in 19 rows at mid-body, reduced posteriorly to 17 rows; these characteristics distinguish this snake from all other Trinidad snakes. Juveniles with dark brown blotches four or five scale rows wide on dorsal midline and separated by light tan bands, one or two scale rows wide on mid-line. Dark bands narrow toward venter, light bands widen toward venter.
Similar Species: Trinidad and Tobago have few snakes that have a dorsal pattern of transverse bands and keeled scales, the coral snakes and their mimics have bands, but they tend to be slender, smooth scaled snakes. But, Linne’s Swamp Snake has bands when young but it has 17 scale rows, and the Water Coral has triangular-shaped markings and its pattern also contains red, but it has 15 rows of dorsal scales.

Habitat: An aquatic snake found in herbaceous swamps; ponds, ditches, slow moving; streams; rice paddies; flooded pastures.

Natural History: Nocturnal. Diet includes lizards, fish, and frogs. Reproduction clutch sizes are 8–18; some populations of this snake may be facultative ovoviviparous; incubation is 39−45 days. We found a clutch of eight eggs beneath corrugated tin about 10 meters from a water filled ditch in September.

Anaconda or Huilla, Eunectes murinus (Family Boidae)

Size. 7.6 m TL, females larger than males, neonates about 65 mm TL. The largest extant snake but not the longest. Diagnosis. The lack of labial pits, four symmetrical scales between eyes, and presence of subocular scales (between the eye and upper labials) will distinguish the anaconda from all other Trinidad and Tobago snakes. Loreal single; one preocular; one to four postoculars; usually two, sometimes one or three suboculars; 14–17 upper labials; 15–25 lower labials; 241–269 ventrals; anal plate single; 65–72 single subcaudals. Small, smooth dorsal scales in 53–69 rows at midbody. Dorsum olive brown with one or two rows of 36–45 dark brown or black blotches, and a lateral row of light-centered ocelli. Distribution. Widespread Amazonian species: Venezuela, Colombia, Brazil, Ecuador, Peru, the Guyanas, Trinidad (not present on Tobago). Life History. A highly aquatic, nocturnal species that uses swamps, marshes, rivers, and quarries. Diet includes a variety of vertebrates: amphibians, reptiles, birds and mammals. Reproduction. Courtship and copulation in December-January, 19–82 young born in July-August. Other common names: Anaconda, Huilla (pronounced 'weel') Water Boa,

Red Snake, Erythrolamprus ocellatus (Family Dipsadidae)

Size: 400–530 mm TL, hatchlings about 180 mm TL; tail 19.8% of SVL. Identification: The only Tobago snake with a red dorsum and a series of 21–28 dark ocelli on body with white-yellow center. Rostral visible from above; single loreal; divided nasal; one preocular; two postoculars; seven upper labials (3−4 enter orbit); nine lower labials; 168–179 ventrals; cloacal plate divided; 40–49 paired subcaudals; smooth dorsal scales in 15 rows at midbody with no reduction posteriorly; anterior chin shields larger or equal in size to posterior pair. Head black, red scales tipped with black, belly is white with some red pigment intruding from the dorsum. Habitat: Uses forest and forest edge habitats as well as cacao plantations.Biology: Diurnal particularly in early morning. Diet: snakes: Atractus trilineatus, Tantilla melanocephala, and the lizard Hemidactylus mabouia.