Scorpion Mud Turtle, Kinosternon scorpioides (Family Kinosternidae)

A relatively common turtle in Trinidad.

Carapace is domed with three well-developed longitudinal keels which become less obvious with age. Attains 175 mm in length. The plastron is hinged between the pectoral and abdominal scutes, and there is no posterior anal notch. The head is large with a projecting snout and hooked upper jaw. Two large barbles on the chin are followed by two or three smaller pairs. The head is gray- brown, darker above and lighter laterally; the jaws uniform yellow or streaked. Neck, limbs, and tail are gray brown. Carapaces of both sexes are about the same length, but is broader in females.

It occurs at low elevations from southern Tamaulipas, Mexico, southward to northern Argentina, Bolivia, and northern Peru. It is widespread on Trinidad, unknown from Tobago. The species is polytypic with four subspecies.

Habitat includes streams, rivers, lakes, and ponds. If its waterway dries up, it will bury itself in the mud bottom until the next rain. It is omnivorous. Diet includes algae, plants, insects, mollusks, fish, and amphibians. Nesting occurs from March to May. Clutch size is 6-16 eggs, requiring about 90 days of incubation time. Spinks et al. (2014) supported previous research suggesting there is much uncertainty regarding species delimitation in the K. scorpioides and K. subrubrum groups. They suggest a taxonomic revisions within these groups would be premature.

Yellow-headed Sideneck Turtle, Podocnemis unifilis (Family Pelomedusidae)

Occurs as a waif in Trinidad waters. A 10 September 2012 a story in Newsday reported several individuals of this species on Manzanilla Beach; the article included a photograph confirming the identity of the turtles as this species.
Maximum carapace size about 680 mm in females, about 330 mm in males; hatchlings are about 40 mm in carapace length. 

 
Carapace dark brown to black, oval with a low medial keel on the second and third vertebral scutes; posterior portion is flared; overall coloration is mostly gray; it lacks the interorbital groove found in all other species of the genus Venezuelan specimens tend to have a single chin barbel. Juveniles have yellow and orange head spots including one on the snout; these fade quickly in females but are retained by adult males. Similar species: Perhaps most easily confused with Podocnemis expansa that has only yellow head spots, and lacks the spot on the snout; it also lacks the medial keel found in this species. Smooth skin on the head of this species will distinguish it from Mesoclemmys gibba which has granular skin on its crown. 

Widespread in the Amazon and Orinoco basins. 

A highly aquatic species, that basks on occasion, it uses small streams, ponds, and flooded forest and during the dry season restricts it activity to remaining bodies of water. Diurnal, but nesting occurs at night. 

Its diet is mostly herbivorous including fruits, stems, and leaves of aquatic plants; but also includes molluscs and dead fish. 

It nests earlier in the season than P. expansa, and females do not form the large nesting aggregations that its congener does. Nesting occurs on sandbanks close to the water. Clutch sizes range from 19−41 with larger females producing more eggs. This turtle is hunted by humans for food.

Red-footed Tortoise, Chelonoidis carbonarius (Family Testudinidae)

Average carapace length: males 250−360 mm, females 260−330 mm, hatchlings 56−61 mm; some individuals reach exceptional sizes 410−512 mm. A terrestrial turtle, with cylindrical legs. The carapace has a relatively flat top, is black with small yellow areas around the areolae; limbs also black, scales have red tips; carapace of males constricted in the center. In the Neotropics it can only be confused with G. denticulata, which as a brown carapace, the areola are lighter in color that outer parts of the scute, but the color change is not well defined and it has scales on the limbs and hear yellow or orange.

It ranges from southern Panama, Colombia (both sides of the Andes), Venezuela, Guyana, French Guiana, Suriname, Brazil, Peru, E Bolivia, Paraguay, N Argentina. West Indian island population may have resulted from over water dispersal (tortoises float well), human-mediated dispersal (humans transport them for food) or a combination of both.

This is a grassland, savanna, open scrub forest, gallery forest, stands of Mauritia palms surrounded by savanna, and it seem to be tolerant of forest–edge as well as inhabiting rainforest in low densities in areas with nearby savanna. It has also been found using cultivated land. In forest and forest-savanna mosaics it is sympatric with G. denticulata. Trinidad underwent multiple shifting habitats from having lowlands submerged to savanna, to forest and because it has been connected – isolated and re-connected to Venezuela many times there is reason to think this tortoise was part of the native fauna. It is diurnal. Its diet includes a variety of fungi, plant and animal material, and preferred foods are those easily fermented with a high concentration of minerals. This tortoise feeds primarily on fruits and found 90% of the seeds in scat samples intact, implying tortoises can be important seed dispersers. 

Courtship behavior seems to keep females of this species from breeding with C. denticulata; male C. carbonarius approach another tortoise head on and perform a single sideways sweep the head (courting male C. denticulata uses a series of lateral jerks) if the tortoise approached is a male it responds with a similar display, and the behavior that follows may result in a fight. If the animal approached does not respond the male sniffs the cloacal area and mating may follow. Courtship and copulation are initiated by the rainy season. Nesting occurs from July to September on the mainland; clutch size is 2−7; females excavate a nest with their hind legs; incubation 105−220 days, average about 150 days.
Humans are major predators of this tortoise, in Venezuela it is a traditional meal during holy week, and while the turtle is protected in Venezuela and other countries, it continues to be collected and eaten. Other common names In Venezuela this species and G. denticulata, are known as the morrocoy. The preferred English name for this species is red-footed tortoise.

Morocoy, Yellow-footed Tortoise, Chelonoidis denticulata (Family Testudinidae)

An uncommon tortoise on Trinidad. Size: Reaches 70 cm in carapace length (males), although usually most specimens do not grow beyond 50 cm; males smaller than females; hatchling carapace lengths 47−56 mm. A large terrestrial turtle with cylindrical legs; carapace shape variable may be flat or domed; males lack a constriction of the carapace. On Trinidad it could only be confused with C. carbonaria. This species has a carapace pattern that has less contrast than C. carbonaria; the carapace is brown, the areolae are lighter than outer portion of scutes; scales on legs and head markings are yellow or orange.Distribution is Amazonian (SE Venezuela, lowland Guyana, French Guiana, and Surinam; Amazon Basin of Brazil isolated population in eastern Brazil, eastern Ecuador, Colombia, northeast Peru, north and eastern Bolivia). In the West Indies it has been introduced into Guadeloupe and St. John (US Virgin Islands). In Trinidad it probably existed in the lower elevations throughout most of the island, and now may be restricted to localized areas. All Trinidad museum material lacks specific locality data. Habitat: A deep rainforest species, which may use more open habitats including tree falls in forested areas and forest edge, found up to 800 m in elevation. It is diurnal. Diet is omnivorous including fungi, plants, live insects, and carrion. Courtship displays differs from that of G. carbonaria (see that account). Reproduction may be seasonal and geographically variable. Clutch sizes of 10−20 eggs reported, but may be smaller 1-8, with an average size of 4 to 5 per clutch. Females may produce two clutches per season. Females may construct a nest and bury eggs, or they may be laid in the leaf litter and not covered with soil. Incubation is 128−152 days (average about 136).

Other common names: morocoy, morrocoy; morrocoy amarillo. English names for this species include yellow footed tortoise, South American forest tortoise, and Brazilian giant tortoise.

American Crocodile, Crocodylus acutus (Family Crocodylidae)

This species may occur as a waif in Trinidad and Tobago waters. It is unlikely to be represented by an established extant population. Size to 7 m. A large crocodile with a preobital hump which will separate it from the Orinoco Crocodile. The fourth tooth in the lower jaw is visible, and it lacks the interorbital ridge these will distinguish it from the common caiman which has the fourth tooth hidden and a distinct interorbital ridge.Distribution includes central Mexico southward through Central America, present on both coasts; on the Pacific as far south as northern Peru and to at least the mouth of the Orinoco along the northern coast; the Caribbean, and southern Florida. Some 19th century authors considered this species part of the Trinidad herpetofauna and it has been found in archeological sites. Currently most crocodilian biologists would consider Trinidad specimens waifs from other populations. Thus it appears that this large animal was at one time present in Trinidad and is now extirpated, possibly due to human predation, habitat destruction, or some combination of these factors. Mangrove forests, salt marshes, and brackish creeks are likely habitats but it also occurs in larger freshwater rivers and freshwater lakes with access to coastal areas. Adults use a den 3-9 m into a stream bank with the entrance below the waterline. Eggs are deposited in a mound nest.

Spectacled Caiman, Caiman crocodilius (Family Alligatoridae)

Caiman crocodilus is a widespread species ranging from Oaxaca, Mexico, southward to the Paraguay River in Paraguay. C. c. crocodilus has an Amazonian distribution. It occurs on Trinidad and Tobago, and possibly other near-shore islands. On both islands, it is found at lower elevations, although it will follow streams into hills and colonize man-made reservoirs. Caimans inhabit brackish and freshwater environments in Trinidad. It is best seen at night standing on bridges over streams and looking for eye shine along the banks and on the water's surface. Courtship occurs in the dry season and early wet season; nests are made of grass in grassland habitats, and leaves, twigs, and soil are used in forest habitats; vegetation is formed into a mound, a nest chamber is excavated, and eggs deposited; the sequence requires 2-7 days; mean clutch size is 28.6; nests are visited and repaired by females. The matte, Tupinambis cryptus, is the major nest predator. The photo below was taken in Nariva Swamp.

An addition to the herpetofauna of Tobago, Anolis tigrinus

Anolis cf tigrinus from Tobago. JCM

Since the 17th century the island of Tobago has been explored by a variety of naturalists including many people who examined the herpetofauna by actually doing field work , others who examined museum specimens, and some that did both. The island is relatively small (~ 300 sq km) but has the oldest protected mature forest in the western hemisphere.

One of the biogeographic puzzles surrounding Tobago is that it has no native members of the genus Anolis. It does have the Giant Crown Anole (Anolis richardii) which is thought to have been introduced from Grenada and it does have Anolis aeneus which appears to be a very recent introduction (probably in the last 20 years). Both of these species are associated with disturbed habitats. We should add that Little Tobago Island (97 ha) is also missing a native anole.

Trinidad, while it is a larger island (~4780 sq km), has only a single known species of native anole, Anolis planiceps (formerly known as Anolis chrysolepis planiceps). However it too has introduced anoles, (A. aeneus, A. trinitatis, A. wattsi, A. extremus, and probably at least another two or three species which we will discuss in a future post).

During the 2015 Tobago Bioblitz (October 24-25) we discovered a small anole, with a body length of about 34 mm, and a mossy green-grey, lichen-like dorsal pattern. Our preliminary results suggest this is Anolis tigrinus Peters. The coloration, body form (slender with short arms and legs) and the scale counts we did all suggest that this is A. tigrinus or something closely related to it.

Anoles come in ecomorphs depending on what microhabitats they exploit, there are trunk-crown ecomorphs (largest body size), trunk-ground ecomorphs (slightly smaller than the previous morph), twig morphs (smaller yet), and the grass-bush morph which is the smallest known morph.

The habitat and distribution of Anolis tigrinus given by Ugetto et al. (2009) was  premontane and montane forest from central Falcón and Yaracuy through Aragua, Distrito Federal, Vargas and Miranda to northern Anzoátegui and southwestern Sucre. Our Tobago record expands the range about 280 km to the northeast.

Anolis tigrinus is a small anole and usually consider a twig morph with males reaching a maximum body length of about 55 mm and females being slightly larger at about 58 mm. Twig anoles use the tips of branches in the crowns of trees, the smallest of perches. This allows them to feed where other, heavier bodied anoles cannot go and gives them a better chance at avoiding their vine snake predators (Oxybelis aeneus and Imantodes cenchoa).

The head is elongate and has relatively large, smooth scales. The supraocular area has a few enlarged scales surround by many smaller, more granular scales. The supraorbital semicircle scales on both sides usually make contact, but may occasionally be separated by one scale; interparietal and supraorbital semicircle scales usually make contact. Dorsal scales small and smooth and from two rows of slightly enlarged scales along the middorsal line.

The most recent review of Anolis tigrinus was done by Ugetto et al. (2009) and they describe its habitat as humid and very humid premontane forests between 980 and 2087 m in Venezuela. It occurs along forest edges and invades the forest for short distances and they are often about three meters off the ground. The individual we found was on the ground in an edge situation and was likely blown off the tree by the wind or fell when it was being chased by a predator. The highest point on Tobago is about 550 m and this specimen was taken at about 400 m ASL. Thus, the Tobago population differs in inhabiting a lower elevation than other clade members.

Ugetto et al. (2009) also reported that male tigrinus have an unspotted dewlap, which is decidedly larger than that of females, and that males are easily recognized by the presence of large, postanal scales and the base of the tail is distinctly wider. While the Tobago specimen has a spotted dewlap, it also displays a hemipenal bulge suggesting it is an adult male. Its stomach contained small wasps.

Del Rosario Castañeda and De Queiroz (2013) found Anolis tigrinus in a clade of nine species (A. lamari, A. menta, A. nasofrontalis, A. paravertebralis, A. pseudotigrinus, A. ruizii, A. solitarius, A. tigrinus, and A. umbrivagus). They share a small body size (40-60 mm adult male body size) large smooth head scales, a large interparietal scale bordered by large scales and usually in contact with the supraorbital semicircle scales, and smooth ventral scales that are larger than dorsal scales. Species in the tigrinus series are distributed at high elevations of the Sierra Nevada de Santa Marta (Colombia), the Andes of Colombia (Eastern Cordillera) and Venezuela, and the Atlantic forest of southeastern Brazil. They considered that the tigrinus series may be nested within the punctatus series representing a twig ecomorph subgroup of the punctatus series which also contains trunk-crown anoles. Del Rosario Castañeda and De Queiroz consider A. tigrinus and its relatives part of the punctatus series rather than a separate tigrinus series, but note that a clade containing A. tigrinus and all species closer to it than to A. punctatus could be recognized as a sub-series or a species group within the punctatus series.

The presence of Anolis tigrinus on Tobago supports the faunistic relationship between the Caribbean Plate island and the Coastal Ranges of Venezuela.

We collected tissue for molecular work and will soon know if it is identical to A. tigrinus or if it is a  relative. We also have evidence that Anolis tigrinus or something similar to it is present on Trinidad.

Literature cited

Del Rosario Castañeda, M., & De Queiroz, K. (2013). Phylogeny of the Dactyloa clade of Anolis lizards: new insights from combining morphological and molecular data. Bulletin of the Museum of Comparative Zoology, 160: 345-398.

Ugueto, G. N., Rivas, G., Barros, T., & Smith, E. N. (2009). A revision of the Venezuelan anoles II: redescription of Anolis squamulatus Peters 1863 and Anolis tigrinus Peters 1863 (Reptilia: Polychrotidae). Caribbean Journal of Science, 45: 30-51.

Authors: Tom Anton, Renoir Auguste, Alvin Braswell, John C. Murphy, Mike G. Rutherford

Reasons to further explore the Trinidad & Tobago Herpetofauna

A satellite map of Venezuela and the surround area. The location

 of the Peninsula de Paria is indicated by the rectangle in the 

upper right hand corner. The insert shows a closeup of the 

peninsula and adjacent Trinidad (T). Three centers of endemism 

are labeled Cerro Humo (H), Cerro Patao (P) and Cerro Azul 

(A). The scale bar is 50-0 m. A Google Earth map. From 

Kaiser et al. 2015. 

The Peninsula de Paria in extreme northeastern Venezuela is an extension of a chain of high coastal mountains (elevations ~2800m) that span much of northern Venezuela and extends into the adjacent islands of Trinidad. The fauna of Tobago is also related to the Peninsula de Paria but from a different history. This region has been variously called the Cordillera de la Costa or the Coastal Range and the eastern continental extension has received minimal attention from herpetologists. Donoso-Barros (1965) reported survey results from Cerro Azul and described Mannophryne riveroi (Donoso-Barros, 1965a), the first endemic frog from the area, followed by Gonatodes ceciliae in 1966, the first endemic lizard - which is now also recognized from Trinidad. Stephen Edwards explored Cerro Azul and recognized a distinctive frog described many years later as Mannophryne venezuelensis by Manzanilla et al. (2007). Two centrolenid frogs, Celsiella vozmedianoi (Ayarzagüena & Señaris, 1997) and Vitreorana castroviejoi (Ayarzagüena & Señaris, 1997), were discovered on Cerro Humo. Rivas et al. (1999) described the microteiid Anadia pariaensis, Mijares-Urrutia et al. (2000) described the gymnophthalmid lizard Euspondylus monsfumus, and Barrio-Amorós et al. (2006) named Allobates caribe, all from the same area. Other herpetologists visited the Península de Paria and made important collections (e.g., Stefan Gorzula in 1978, Jose Ayarzagüena in 1996) but no additional species have been described from their material. With the completion of more extensive collections by several Venezuelan and international research teams, additional species and observations on poorly known species were recently published (e.g., Anadia pariaensis—Rivas et al. 2012; Strabomantis biporcatus—Barrio-Amorós & Kaiser 2008; Mannophryne riveroi—Barrio-Amorós et al. 2010a; Riama rhodogaster—Rivas et al. 2005; Taeniophallus nebularis Schargel et al. 2005).

In a recent paper Kaiser et al, (2015) reported on fieldwork in the cloud forest of Venezuela’s remote Península de Paria in 2001 resulted in the collection of several specimens that could unquestionably be classified as members of the genus Pristimantis. Subsequent analysis of comparative material in museum collections brought the total number of specimens to 44, and these collectively represent five new species. Two of these species, P. geminus and P. nubisilva have phenotypes remarkably similar to the Trinidadian P. urichi, supporting a prediction that Pristimantis from easternmost Venezuela may have given rise to Trinidadian forms. Pristimantis hoogmoedi is easily identified by its large size and red eyes. Two of the species, P. longicorpus and P. pariagnomus, are very distinct morphologically but are known only from the holotypes. The former is characterized by an elongate body form supported by relatively short limbs, whereas the latter has very distinctive hand morphology and is likely the smallest Venezuelan frog. All five species can be readily distinguished by their osteology, such as by the extent of the sphenethmoid and features on the roof of the mouth, as well as by the shape and rearrangement of mesopodial elements. The unexpectedly high diversity of Pristimantis in this region, along with high endemism of amphibians and reptiles in general, underscores the position of the Península de Paria as a center for frog biodiversity in Venezuela. The authors conclude that the similarity of these Paria species to Pristimantis from Trinidad, Tobago and the central Cordillera de la Costa represents a tangible piece of evidence for the close biogeographic link of the anuran fauna of these landmasses.

The Trinidad and Tobago herpetofauna is more diverse than previously thought. By previously I mean post-Kenny (1969-1979), post-Murphy (1997), post-Boos (2001). Each of those works were a snapshot of what we knew at the time but knowledge changes.

Species recently described or ones that have been resurrected from obscurity on Trinidad and Tobago are numerous, and include the following. Frogs: The Orinoco Basin Dendropsophus goughi (Boulenger) was formerly the widespread D. minuta. Scarthyla vigilans was recently reported from Trinidad by Smith et al. (2011). While it may have been a recent colonization, it is also possible it was simply over looked because it so closely resembles the widespread Scinax ruber.  Leptodactylus insularis was formerly L. bolivianus (Heyer and Heyer, 2013). Changes in lizards. The skink Mabuya falconensis is now Marisora aurulae Hedges & Conn, 2012, a species with a very small distribution on several islands and known from few specimens. And the skink, once thought to be the widespread Mabuya bistriata is now Copeoglossum aurae Hedges & Conn, 2012, with a very restricted distribution. The Trinidad zandolie which was once thought to be the widespread Ameiva ameiva is now the Caribbean Costal Range endemic Ameiva atrigularis (Ugueto et al. 2011). The once widespread Plica plica is now the Caribbean Costal Range endemic Plica caribeana (Murphy and Jowers, 2013). As for snakes the endemic Leptophis haileyi was added to the fauna of Tobago by Murphy et al. Dipsas variegata was added to the Trinidad fauna by Murphy and Rutherford (2014). Teddy Angarita-Sierra (2014) added the snake Ninia franciscoi, which has only been collected at Simla, in the Arima Valley, but may also be present in the Caribbean Coastal Range.

So if I made a list of the number of species that need name changes or descriptions (because they are undescribed) I am confident the list would contain twelve species. If I estimate the number of actual changes that are probably needed the number goes to at least twenty, about a quarter of the herpetofauna.

With these changes widespread species become less widespread, there are more endemic and near endemic species and the fauna becomes more specialized and more diverse. In short it becomes a more valuable resource in terms of culture, conservation, aesthetics, and science.

These changes don’t happen for free. They are funded by private and public money. If you are interested in supporting this research contact me at serpentresearch@gmail.com. We need funding for several projects.

References

Ayarzagüena, J. & C. Señaris (1996). Dos nuevas especies de Cochranella (Anura; Centrolenidae) para Venezuela. Publicaciones de la Asociación de Amigos de Doñana 8: 1–16.

Barrio-Amorós, C.L., G. Rivas & H. Kaiser (2006). New species of Colostethus (Anura, Dendrobatidae) from the Península de Paria, Venezuela. Journal of Herpetology 40: 371–377; http://dx.doi.org/10.1670/0022-1511(2006)40[371:NSOCAD]2.0.CO;2.

Barrio-Amorós, C.L. & H. Kaiser (2008). Distribution of Strabomantis biporcatus (Terrarana: Strabomantidae) in northern Venezuela, with comments on its phenotypic variation. Salamandra 44: 248–254.

Boos HEA. 2001. The Snakes of Trinidad and Tobago. College Station: Texas A&M University Press. 270 pp.

Donoso-Barros, R. (1965a). Nuevos reptiles y anfibios de Venezuela. Noticiario Mensual, Museo Nacional de Historia Natural, Santiago, Chile 102: 2–3.

Donoso-Barros, R. (1965b). A new dendrobatidae [sic] frog, Prostherapis riveroi from Venezuela. Caribbean Journal of Science 4: 485–489.

Donoso-Barros, R. (1966). Dos nuevos Gonatodes de Venezuela. Publicación Ocasional del Museo Nacional de Historia Natural, Santiago de Chile 11: 1–32.

Edwards, S.R. (1974). Taxonomic notes on South American dendrobatid frogs of the genus Colostethus. Occasional Papers of the Museum of Natural History, University of Kansas 30: 1–14.

Heyer, W. R., & Heyer, M. M. (2013). Systematics, distribution, and bibliography of the frog Leptodactylus insularum Barbour, 1906 (Amphibia: Leptodactylidae). Proceedings of the Biological Society of Washington, 126(3), 204-233.

Kaiser, H., C.L. Barrio-Amorós, G.A. Rivas, C. Steinlein & M. Schmid (2015). Five new species of Pristimantis (Anura: Strabomantidae) from the coastal cloud forest of the Península de Paria, Venezuela. Journal of Threatened Taxa 7(4): 7047–7088; http://dx.doi.org/10.11609/JoTT.o4197.7047-88.

Kenny JS.  1969. Amphibia of Trinidad. Studies on the Fauna of Curacao and Other Caribbean Islands 29(54):1–78.

Kenny JS.  1971. A further contribution on the Amphibia of Trinidad. Journal of the Trinidad Field Naturalist’s Club 1971:24–25.

Kenny JS. 1977. The Amphibia of Trinidad–an addendum. Studies on the Fauna of Curacao and Other Caribbean Islands 51:91–95.

Kenny JS. 1979b. Some recent colonizations. Journal of the Trinidad and Tobago Field Naturalist’s Club 1978–79:27.

Manzanilla, J., M.J. Jowers, E. La Marca & M. García-París (2007). Taxonomic reassessment of Mannophryne trinitatis (Anura: Dendrobatidae) with a description of a new species from Venezuela. Herpetological Journal 17(1): 13–42.

Mijares-Urrutia, A., J.C. Señaris & A. Arends (2000). Taxonomía de algunos microtéidos (Squamata) de Venezuela, I: Variación y distribución geográfica de Euspondylus del nordeste de Venezuela. Revista de Biología Tropical 48: 671–680.

Murphy, JC. 1997. The Amphibians and Reptiles of Trinidad & Tobago. Krieger Publishing Co. Malabar. 245 pp.

Murphy, J. C., & Jowers, M. J. 2013. Treerunners, cryptic lizards of the Plica plica group (Squamata, Sauria, Tropiduridae) of northern South America. ZooKeys, (355), 49.

Murphy, J. C., Charles, S. P., Lehtinen, R. M., & Koeller, K. L. (2013). A molecular and morphological characterization of Oliver’s parrot snake, Leptophis coeruleodorsus (Squamata: Serpentes: Colubridae) with the description of a new species from Tobago. Zootaxa, 3718(6), 561-574.

Murphy, J. C. and M Rutherford. 2014. The first report of the snail-eating snake Dipsas variegata (Duméril, Bibron and Duméril) on Trinidad, its relationship to Dipsas trinitatis Parker (Squamata, Dipsadidae), and a discussion of microcephalic and macrocephalic ecomorphs in Dipsas. Herpetology Notes, 7, 757-760.

Rivas F.G., E. La Marca & O. Oliveros (1999). Una nueva especie de Anadia (Reptilia: Sauria: Gymnophthalmidae) del noreste de Venezuela. Acta Biologica Venezuelica 19(4): 27–32.

Rivas, G.A., P.M. Sales Nunes, J.R. Dixon, W.E. Schargel, J.R. Caicedo, T.R. Barros, E.G. Camargo & C.L. Barrio-Amorós (2012). Taxonomy, hemipenial morphology, and natural history of two poorly known species of Anadia (Gymnophthalmidae) from northern South America. Journal of Herpetology 46(1): 33–40; http://dx.doi.org/10.1670/10-139.

Schargel, W.E., G. Rivas Fuenmayor & C.W. Myers (2005). An enigmatic new snake from cloud forest of the Península de Paria, Venezuela (Colubridae: Genus Taeniophallus ?). American Museum Novitates 3484: 1–24; http://dx.doi.org/10.1206/0003-0082(2005)484[0001:AENSFC]2.0.CO;2.

Smith, Joanna, J. Roger Downie, Rebecca F. Dye, Victoria Ogilvy, Daniel Thornham, Michael G. Rutherford, Stevland P. Charles, and John C. Murphy. "Amphibia: Anura: Hylidae Scarthyla vigilans (Solano 1971): Range Extension and New Country Record for Trinidad, WI With Notes on Tadpoles, Habitat, Behaviour and Biogeographical Significance." Check List 7, no. 5 (2011): 574-577.

Ugueto, G. N., & Harvey, M. B. (2011). Revision of Ameiva ameiva Linnaeus (Squamata: Teiidae) in Venezuela: recognition of four species and status of introduced populations in southern Florida, USA. Herpetological Monographs, 25(1), 113-170.

The Golden Treefrog: no longer an endemic to Trinidad

Phytotriades auratus. John C. Murphy

The critically endangered Phytotriades auratus (Boulenger, 1917) commonly known as the golden treefrog was thought to be an endemic species to Trinidad. This hylid grows to about 3.5 cm snout-vent length. In Trinidad, its distribution is restricted to the two highest peaks: El Tucuche (936 m) and El Cerro del Aripo (940 m). At these peaks, P. auratus is closely associated with the bromeliad Glomeropitcairnia erectiflora where it spends the majority of its known life cycle. However, a recent visit to Cerro Humo’s summit in eastern Venezuela brought about the discovery and first documentation of the species outside of Trinidad.

Rivas and de Freitas visited Cerro Humo, Venezuela in August 2014. While at the summit of Cerro Humo, they came across G. erectiflora on a fallen tree trunk along their path. Within the bromeliad, two P. auratus specimens were observed and photographed while a third was spotted on another bromeliad nearby (Rivas and de Freitas 2015). The significance of this find resulted in the range expansion and new country record for this critically endangered species. Given the geological history of Northern Trinidad and Venezuela, this find may not be considered surprising.

Perhaps the most significant aspect with the discovery of a population of P. auratus in Venezuela is that an additional population outside of Trinidad is potentially beneficial towards the conservation of the species. An estimation of the populations in Trinidad was first undertaken in 1995. Currently, an assessment of the Trinidad population is being updated using the eDNA (environmental DNA) method. This method involves collecting water samples from within the bromeliad and testing it for golden treefrog DNA. Based on the results, the number of golden treefrogs can be acquired and an estimate of population size can be deduced. An evaluation of the Venezuelan population is required and perhaps a similar approach can be used for the population in Cerro Humo. With potential threats to P. auratus’s conservation including climate change, habitat alteration, lack of legislative enforcement and the chytrid fungus, scientific research on the populations in both Trinidad and Venezuela is the first step towards reducing the threat status of the species.

Citation

Rivas, G. A. & de Freitas, M.  (2015)  Discovery of the critically endangered golden tree frog, Phytotriades auratus (Boulenger, 1917), in eastern Venezuela, with comments on its distribution, conservation, and biogeography.  Herpetological Review:  46;  153-157.

The disappearing Pauraque eggs

Martyn, Nigel, Sataish and I took on the task of searching for the proverbial needle in a haystack this morning.

That is, hoping that the ovenbird, after being caught in a net and having his feathers plucked would still be around.

Needless to say we did not see him – he wasn’t as dotish as we thought he was.

But something else had us baffled though. On the trek in, we saw a Pauraque (Nyctidromus albicollis) fly off leaving eggs on the forest floor. Martyn marked the spot with a stick so on our return trek we would be alerted before we approached the Pauraque.

However, on the return we saw the stick but not the eggs – they had mysteriously disappeared! Someone suggested the rastaman, and then the scrawny dog who was on the track. But there were no signs of either. There were no other suspects until Sataish jumped like a madman – nearly stepping on a Pseustes poecilonotus polylepis Dos Cocorite Snake (which was id’d by Carl Fitzjames later).

Ah well, Birding took a different turn this morning..! B R. Kamal

Dipsas variegata - the 44th species of snake reported from Trinidad

A comparison of Dipsas trinitatis (A 

and c) and Dipsas variegata (B and D).

Thirty six species of the snail-eating snakes in the genus Dipsas are currently recognized. One species, Dipsas trinitatis Parker is known only from Trinidad. The original description of Dipsas trinitatis (Parker, 1926) was based upon a single male specimen from the Trinity Hills and a second specimen without locality data. Parker recognized its close relationship to the mainland South American Dipsas variegata and distinguished the two species using the presence/absence of a preocular, the number of upper labials, and differences in color pattern, characters now known to be variable in both taxa. In an overall review of dipsadine snakes Peters (1960) relegated D. trinitatis to a subspecies of D. variegata based on color differences from the mainland populations. Emsley (1977), Murphy (1997) and Boos (2001) followed this recommendation and discussed this snake as D. v. trinitatis.

Until now, all references to Dipsas on Trinidad have referred to Dipsas trinitatis Parker. Murphy and Rutherford (2014) have now report the presence of Dipsas variegata on Trinidad. Its presence is based upon a single female specimen, identified as Dipsas trinitatis, was found in the collection of The National Museum and Art Gallery of Trinidad & Tobago and now stored in The University of the West Indies Zoology Museum (UWIZM). Its large size (796 mm total length, 607 mm SVL), bulky head, tall upper labials, an eye diameter that is about equal to the eye-mouth distance readily distinguish it from its congener, Dipsas trinitatis. The specimen agrees well with all 16 diagnostic characters for the species listed by Harvey and Embert (2008).

Collection data accompanying the specimen reports it locality as Macqueripe Bay on the north coast of the Chaguaramas Peninsula and adjacent to Tucker Valley.

The smaller head in D. trinitatis has been noted previously, but placed side-by-side the size difference is dramatic and it appears Dipsas variegata is macrocephalic, while D. trinitatis is microcephalic. Microcephalism evolved in several sea snakes (Hydrophis, family Elapidae, Hydrophiinae) that specialize in hunting snake eels in crevices. The smaller head allows the snake to probe holes and crevices to extract the fish. Since Dipsas feeds on snails and extracts them from their shells it seems probable that the difference in head size is adaptive for a specific type of prey, or a specific foraging strategy (possibly removing snail bodies from shells of different sizes or extracting snails from crevices). Feeding behavior and diet in these snakes is poorly known it is unclear as to how head size relates to diet or foraging.

Dipsas variegata is the 44^th species of snake reported from Trinidad and the second species of Dipsas from the island. In addition there is a third species of snake specialized for feeding on gastropods from Trinidad – Sibon nebulata.

Citation

Murphy JC, Rutherford, MG. 2014. The snail-eating snake Dipsas variegata (Duméril, Bibron and Duméril) on Trinidad, and its relationship to the microcephalic Dipsas trinitatis Parker (Squamata, Dipsadidae). Herpetology Notes, 7: 757-760. 

Hyla goughi Boulenger resurrected for the Trinidad & Tobago Dendropsophus minutus population

Dendropsophus goughi Boulenger

In the Neotropics, nominal taxa such as the toad Rhinella margaritifera (Bufonidae), the thin-toed frog Leptodactylus fuscus (Leptodactylidae), and the tree frog Scinax ruber (Hylidae) are prominent examples of anuran species once considered to occur across nearly the entire tropical lowlands of South America. Evidence has accumulated that many such putatively widespread species could in fact be complexes of cryptic taxa. However, given limited genetic sampling and the difficulty in reviewing material from all countries hosting populations, their relationships and systematics remain in many cases as unclear as they were decades ago.

Dendropsophus minutus (Peters, 1872) is a small hylid frog, 21–28 mm snout-vent length, distributed in Cis-Andean South America, including the Andean slopes, the Amazon Basin, the Guiana Shield, down to the Atlantic Forests of southeastern Brazil, with an elevational record from near sea level up to 2,000 m. Variation in coloration, osteology, advertisement calls and larval morphology, along with molecular data from limited parts of the species' distribution suggest the nominal D. minutus might represent a species complex. However, the sheer size of its supposed geographical range along with nomenclatural and taxonomic complexity (six junior synonyms) and unresolved relationships in the D. minutus species group have so far made these frogs inaccessible to revision.

Gehara et al. (2014) use D. minutus to understand to what degree a small-sized, tropical anuran has the potential to be continentally widespread with limited genetic structure within its range, as expected for a single species. In addition to conservation concerns, this question has important implications for South American biogeography in general and amphibian systematics and evolution in particular. Evidence is accumulating that body size in amphibians has a positive correlation with range size, but contrary to this trend many Holarctic amphibians occur with little genetic substructure across the vast ranges they colonized after the last glaciation, despite sometimes moderate to small body sizes. Whether such patterns also exist across vast ranges in tropical regions, with their distinct historical climatic dynamics, is an open question. Deciphering possible cryptic diversity within the nominal D. minutus would also help inform conservation assessments which typically use species' geographic distributions as criteria for conservation status.

The phylogenetic tree based on the 16S gene containing all Dendropsophus for which sequences were available recovered the monophyly of the D. minutus species group. Within the group, the clade containing samples representing lineages 19–43 received a maximal posterior probability (1.0) and is defined here as the D. minutus complex, given that lineage 25 contains samples from the type locality of D. minutus.

Most of the mitochondrial lineages containing more than one sample received strong nodal support. The lineages splitting off from basal nodes of the tree (lineages 1–18) are distributed in the Guiana Shield, and in the Andean region of Peru, Ecuador and Colombia, with an eastern extralimital clade assembling disjunct localities in Mato Grosso and Pará.

The remaining lineages are in general more widely distributed in central and eastern South America Lineages are largely allopatric but several cases of sympatry were observed. The uncorrected pairwise distances between lineages for the 16S gene ranged from 0.7 to 13%, while within-lineage p-distances ranged from 0.0 to 1.8%.

Most of the lineages (45%) were found in only one or two localities. Fifty per cent of the lineages were only found in areas smaller than 10 km², and more than 70% have known ranges smaller than 10,000 km². Eight out of the 43 lineages have a distribution larger than 100,000 km2. Largest range sizes were found in northeastern Brazil (Caatinga domain; 997,262 km², lineage 36), eastern Bolivia and western Brazil (Cerrado, Chaco and Dry Forest domains; 293,321 km², lineage 33) and the Guiana Shield (269,741 km², lineage 2).

Among the D. minutus species group members external to the D. minutus complex, lineages 1–6 are Guianan, while 7–18 are primarily distributed along the Andean foothills, and all show well-pronounced molecular differentiation and divergence. Among lineages 1–6, there is moderate genetic differentiation. Considering mitochondrial reciprocal monophyly and GMYC results as criteria, and being taxonomically conservative, one available name, Hyla goughi Boulenger, 1911 (type locality: Trinidad), should likely be removed from the synonymy of D. minutus and allocated to populations comprised by all or some of lineages 1–6. As a conservative estimate, the authors hypothesize that lineages 7–18 comprise seven distinct species, i.e., five named taxa and two undescribed species (lineages 9+10 and 11+12).

Data presented herein provide conclusive evidence for a strong genetic subdivision of the nominal species Dendropsophus minutus as currently understood. Current taxonomy conservatively assumes a putatively widespread species encompassing a vast area of South America (from approximately latitude 11.0°N to 35.0°S), distributed across several biomes. Our results, however, reveal high genetic diversity within D. minutus that would suggest the existence of numerous distinct species, leading to an important increase in number of species. If this hypothesis is confirmed through further studies, the existence of an increased number of species with decreased range sizes would have important consequences for the definition of centers of endemism and for assessing conservation status.

Citation

Gehara M, Crawford AJ, Orrico VGD, Rodríguez A, Lötters S, et al. (2014) High Levels of Diversity Uncovered in a Widespread Nominal Taxon: Continental Phylogeography of the Neotropical Tree Frog Dendropsophus minutus. PLoS ONE 9(9): e103958. doi:10.1371/