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/

2014 Trinidad Bioblitz is fast approaching, herpetology participants please read the following

The third annual T&T Bioblitz, taking place this year in and around Nariva Swamp, is coming up on the 18^th-19^th October. 

On the 18th and 19th October wildlife experts and enthusiasts will be taking part in the third annual T&T Bioblitz. This year it is being held in Nariva Swamp and the plan is to try and record as many different species of plants, animals and other organisms as possible within 24 hours. The event is being organized by Mike Rutherford, the curator of the UWI Zoology Museum, in partnership with the T&T Field Naturalists’ Club, Forestry Division and many other groups. The experts start surveying on Saturday 18th at noon and then work through the night before inviting the public along on the Sunday morning to go on guided tours, see science in action and learn more about the local wildlife. Come along and join in!

The Bioblitz in Nariva provides an opportunity to confirm the presence of some interesting animals.

At the top of the list is the matamata turtle. There has been considerable speculation about an established population on Trinidad. Finding one in Nariva would support that idea, but they are very difficult to see and totally aquatic – so the freshwater group may want to keep an eye out for them also. It’s more likely one will turn up in a seine while looking for fish, than someone will actually see one in the water. Other turtles are also of interest and I would encourage people who find them to hang on to them long enough to get positive IDs and photos.

Similarly, it is likely the herp group or the freshwater group will find the totally aquatic frog Pipa pipa. I have not seen these recently, but saw them in abundance in the 1980’s in the southwest portion of the island. Museum and literature records support their presence in Nariva. Collecting one for photos and tissue would be valuable.

Another high priority species is the semi-aquatic lizard, Kentropyx striata, they are present in the Nariva area, I saw one 2012. But they are buggers to catch. When approached they quickly dive into the water, but you will see them sitting in bushes and on logs. Again, collecting one for photos and tissue would be very valuable. Note they look very much like a Cnemidophorus, but Cnemidophorus do not go into the water.

Other high priority species for photos, specimens, and tissues: Polychrus marmoratus (one specimen from Bush-Bush looks quite distinct from those of the Northern Range), Tupinambis teguixin, Hydrops triangularis, Erythrolamprus (Liophis) cobellus, Clelia clelia, Drymarchon corais, Spilotes sulphureus and of course any of the worm snakes. And, let’s not forget anoles, skinks and frogs, interesting specimen may turn up.

It is unlikely we will find crocodiles, river turtles or aquatic caecilians but you never know! Seeing an anaconda is likely so keep your camera’s ready.

Oh, yes, don’t forget road kills. Please pick them up, they are great for voucher specimens and DNA even if they are super flat.

You can find more on the T&T Bioblitz Facebook page

A new snake from Trinidad, and its significance to the big picture

There is no doubt that there are many, many more species of amphibians and reptiles than previously thought. Peter Uetz, maintains the Reptile Database website, and he recently announced that in 2014, the number of known reptile species passed the 10,000 mark – and the year has not yet ended. In an email Uetz wrote the number of reptile species is, “10,038 species (including 79 described this year), up from 9,952 in April”. While some of these species are obviously different, many of them are cryptic, and it takes some detailed study of morphology or DNA to sort them out.

Trinidad is a relatively small island – 4800 square kilometers that has had its herpetofauna relatively well studied. The first list of herps was published in 1858, and the work by Mole and Urich at the turn of the 20th century examined the fauna extensively. William Beebe spent the last years of his life at Simla in the Arima Valley and published a fauna list as well as a paper on the ecology of the valley. Garth Underwood and Michael Emsley also studied and wrote about the island’s herpetofauna. Julian Kenny and Hans Boos were also actively working on the Trinidad herpetofauna for decades. And I made five- or six trips to the islands and examined museum specimens in the 1980-90’s for the 1997 book. During those trips, I frequently stayed at Simla and worked extensively in the Arima Valley. In 2010, I decided to take a second look at the fauna and since that date have made eight trips to investigate the herpetofauna of both Trinidad and Tobago. Additionally, I have been working with colleagues to compare museum material from the islands to those from the mainland – the results are startling.

It has become quite obvious to me that the diversity of reptiles on that 4800 sq km, well studied island (as well as the island of Tobago) is much greater than what I (or anybody else) thought it was in 1990.

Within the last few years, we have described Plica caribeana and Leptophis haileyi. The Plica is a Caribbean Coastal Range species, and the Leptophis appears to be a Tobago endemic. There are more species forthcoming – for the most part it is a matter of time and money to get the work done. But, preliminarily we have identified at least ten more species of squamate reptiles currently unrecognized from the islands or masquerading under the name of a widespread species.

In a forthcoming paper in the Journal of South American Herpetology, Teddy Angarita-Sierra describes a new, cryptic species of coffee snake, in the genus Ninia – from Trinidad. It would normally not surprise me, that a small, leaf litter dwelling snake would go un-noticed in the tropics. But, this snake is surprising because the of the type locality – Simla. A location that has to be the most closely examined piece of real estate on the island – in terms of its fauna.

Ninia atrata left, Nina franciscoi sp. n. right. T. Angarita-Sierra

Angarita-Sierra describes Ninia franciscoi, from a single specimen collected at Simla 6 March 1988 by William B. Montgomery and David Resnick. This specimen looks very much like the widespread Ninia atrata (also found at Simla) except for the number of upper labials contacting the primary temporal and most importantly, an unusually shaped hemipensis (see right).

Nina franciscoi sp n.,top, Nina atrata bottom.

After reviewing this paper – I went back and looked at about forty specimens of Ninia atrata from Trinidad and Tobago as well as all of my photographs, looking to see if any of the others had the primary temporal in contact with three upper labials. Some of these specimens were collected at Simla – none showed this trait.

So, what is the significance of this? Below is a power point slide I used in a recent presentation comparing the number of reptile species per 1000 km² in Trinidad & Tobago to Venezuela. The islands are much better studied than the mainland. Trinidad & Tobago have 4.2x more known species of reptiles per 1000 km² than does Venezuela (this is using the numbers from the 1997 book). In other words mainland South America (specifically Venezuela) most likely has a vast number of undescribed reptiles.

As for those undescribed Trinidad and Tobago squamates - one of them is a third species of Ninia. Below is typical Ninia atrata. 

Gymnophthalmus underwoodi on Tobago

The shiny lizard, Gymnophthalmus underwoodi, is one of those reptiles that is widespread and probably common,  but not particularly easy to find. It is small, lives in burrows or under objects, and is active only when the sun is shining - when it can significantly raise its body temperature. Its distribution ranges from Venezuela, the Guyanas, and Brazil northward into the Lesser Antilles. It has been reported as far north as Antigua. Humans may, at least in part, be responsible of its island distribution.The shiny lizard is frequently associated with lawns and gardens and as people transport their favorite plants from palace to place these tiny lizards may move with them. Additionally it is a unisexual species which provides the advantage of not needing a mate. In fact, G. underwoodi is one of four species in a complex of cryptic species (the others are: G. cryptus, G. leucomystax, and G. specious). Kiziran & Cole (1999) found G. cryptus is the ancestor of G. underwoodi.

Hardy (1982) commented on the lack of specimens of Gymnopthalmus underwoodi from Tobago, Cole et al did find find specimens from Tobago, nor did Murphy (1997). Yet some publications and websites have included Tobago in the distribution- the IUCN red list is an excellent example. It presence on Tobago would seem reasonable given its presence in Trinidad and Venezuela and the Antilles. However, a HerpNet search did not show any specimens from Tobago.

On 6 June 2013 Rick Lehtinen collected a single specimen of G. underwoodi in from of the Vegetable King in Castara, Tobago. Thus confirming its presence on the island. The specimen is deposited in the UWIMZ. Since that date the species has become quite abundant on the northeastern end of the island.

Literature

Cole, CJ, et al. Gymnophthalmus (Reptilia Teiidae) in the neotropics: genetics origin and systematics. American Museum Novitates (2994): 1-29

Hardy, J. D. 1982. Biogeography of Tobago, West Indies, with special reference to amphibians and reptiles, a review. Bulletin of the Maryland Herpetological Society 18(2):37–142.

Kizirian DA. Cole CJ. 1999. Origin of the Unisexual Lizard Gymnophthalmus underwoodi (Gymnophthalmidae) Inferred from Mitochondrial DNA Nucleotide Sequences. Molecular Phylogenetics and Evolution 11:394–400.

Murphy, J. C. 1997. Amphibans and reptiles of Trinidad ad Tobago. Krieger Publishing, Malabar, FL.

Is Chironius scurrulus part of the Trinidad herpetofauna?

In 1993 Dixon et al. reported on a specimen of Chironius scurrulus from Trinidad. The specimen, UMMZ 43965 is a juvenile that was collected by E. B. Williamson, an insect collector at the turn of the 20^th century (winter 1912). Wagler’s Sipo as it is sometimes called inhabits Brazil, SE Colombia, N Bolivia, Ecuador, Venezuela, E Peru, Trinidad, Guyana, Surinam, French Guiana according to the Reptile Database website, and probably has a type locality of Rio Japura, Brazil (based on comments in Kornacker 1999). Boos (2001) also reported this species as part of the Trinidad herpetofauna, following the previous authors.

The UMMZ specimen of Chironius scurrulus said to be from Trinidad

Recently I visited the UMMZ and examined the specimen of Chironius scurrulus, it is undoubtedly that species, but there is evidence to suggest it did not come from Trinidad.  Also collected by Williamson that winter on Trinidad were some Rhinella marina, Hypsiboas crepitans, Mannophryne trinitatis, and several specimens of the stream toad, Atelopus hoogmoedi. The last species is of course unknown from Trinidad – but it is known from Guyana, the other country visited by Williamson during the winter of 1912. Given the low probability of picking up the only known specimen of Chironius scurrulus and the only known specimens of Atelopus hoogmoedi from Trinidad on one trip, it seems likely that the specimens were instead collected in Guyana and at some point mislabeled as to their origins.

I would like to thank Greg Schneider at the UMMZ for searching the archives for information on these specimens, and to César Luis Barrio-Amorós, J. Roger Downie, and Joanna Smith for their perspectives into these records.

Citations

Boos, H.E.A. 2001. The snakes of Trinidad and Tobago. Texas A&M University Press, 270 pp.

Dixon, J. R., Wiest Jr, J. A., & Cei, J. M. 1993. Revision of the neotropical snake genus Chironius Fitzinger Serpentes, Colubridae. Torino: Museo regionale di scienze naturali.