Whistling frogs synonymized

Leptodactylus validus and tadpoles on Tobago. JCM

The very abundant whistling frog, Leptodactylus validus, has been long considered a Caribbean species, with populations in the Lesser Antilles, Trinidad and Tobago. In 2006, Yanke et al. used molecular data to demonstrate that the South American whistling frog, L. pallidorostris was conspecific with the Caribbean whistling frog. Leptodactylus pallidorostris inhabits Venezuela, Guyana, Suriname, and French Guiana.

In a more recent paper, Heyer and Heyer (2012) compare calls, larval morphology and adult morphology that agree with the molecular results, Leptodactylus validus occurs in in the Lesser Antilles (as far north as Bequia), Trinidad and Tobago, as well as northern South America.

As more molecular and morphological  information on the Trinidad and Tobago herpetofauna becomes available a more detailed and refined biogeographical portrait of the islands will emerge.


Literature Cited
Heyer W.R. and M/ M. Heyer (2012) Systematics, distribution, and bibliography of the frog Leptodactylus validus Garman, 1888 (Amphibia: Leptodactylidae). Proceedings of the Biological Society of Washington, 125:276-294.

Yanek, K., W. R. Heyer, and R. O. de Sa´. 2006. Genetic resolution of the enigmatic Lesser Antillean distribution of the frog Leptodactylus validus (Anura, Leptodactylidae). South American Journal of Herpetology 1:192–201.

Treeboa Phylogeny

A Tobago specimen. JCM

Treeboas of the genus Corallus (subfamily Boinae), had a Gondwanan origin. As noted in the previous post there are eight species  recognized based on morphology and some have been confirmed with molecular data: C. annulatus, C. batesii, C. caninus, C. cookii, C. cropanii, C. grenadensis, C. hortulanus, and C. ruschenbergerii. Four of these species are endemic to South America, including the rare and very poorly known C. cropanii, which is known from four specimens (three existing) and whose taxonomic placement has been of great interest. Two species are distributed in both Central and South America (C. annulatus and C. ruschenbergerii), and two species are endemic to the Lesser Antilles (C. cookii and C. grenadensis). Phylogenetic relationships have been explored using morphology and molecular phylogeographic analyses have been conducted on 115 individuals. However, a time-calibrated phylogeny for all species has not been available.

In a forthcoming paper, Colston et al. (2013) use DNA sequence data from two mitochondrial and three nuclear genes from all species of Corallus to infer their phylogenetic relationships and reconstruct their biogeographic history. The authors find Corallus diversified within mainland South America, and disperse over-water to the Lesser Antilles and Central America, and they used the traditionally recognized Panamanian land bridge. Divergence time estimates reject the South American Caribbean-Track as a general biogeographic model for Corallus and suggest Oligocene and Miocene played a role diversification. These events include marine incursions and the uplift of the Andes. The results also suggest that recognition of the island endemic species, C. grenadensis and C. cookii, is questionable as they are nested within the widely distributed species, C. hortulanus.

The research suggests that Ruschenberg's treeboa C. ruschenbergerii dispersed from South America to Central America during the Pleistocene via the traditionally recognized Panamanian land bridge, although the results also allow for the possibility that C. ruschenbergerii may have arrived in Central America prior to the closure of the Panamanian Isthmus in the middle Miocene.

Citation

Colston, T.J., et al. (2013) Molecular systematics and historical biogeography of tree boas (Corallus spp.). Mol. Phylogenet. Evol., http://dx.doi.org/10.1016/j.ympev.2012.11.027

Treeboa Diets

 Ruschenberg's treeboa from the Frenchman's River, Tobago. JCM

Nine species of  Neotropical treeboas in the genus Corallus range from southeastern Guatemala to southeastern Brazil. Based largely on previously published papers, Henderson and Pauers (2012) accumulated records for 271 prey items for all species combined. Prey reported were: 2 frogs, 69 lizards (mostly Anolis), 1 snake, 65 birds, and 134 mammals (mostly marsupials, rodents, and  bats). The authors found a conspicuous difference in diet between the two West Indian species (C. cookii and C. grenadensis) and species occurring on the mainland. Juvenile and subadult boas from the West Indies prey almost entirely on anoles, whereas on the mainland (with the notable exceptions of C. batesii and C. caninus), preyed mostly on birds and bats. Four species (C. cookii, C. grenadensis, C. hortulanus, and C. ruschenbergerii) are vertebrate generalists and exhibit both active foraging and ambush hunting modes. Adult C. batesii and C. caninus (and, perhaps, C. cropanii) are specialists on mammals, and may only use an ambush hunting techniques, and these were the only species that did not have at least three records of birds in their diet. Although more common than the critically endangered C. cropanii, both C. annulatus and C. blombergii seem genuinely rare and it is premature to make any generalizations regarding their trophic biology.

 The longest of the nine treeboa species is Ruschenberg's treeboa, but it has less bulk than three of the other species (batesii, canius, cropanii) based on body girths. Ruschenberg's treeboa has a large distribution, ranging from Costa Rica to Venezuela, and it occurs on Trinidad, Tobago, and the Isla de Margarita. The authors found it feeds on lizards, birds, marsupials, rodents and carnivores (mongoose).

Citation
Henderson, R. W. and Pauers, M. J. 2012. On the Diets of Neotropical Treeboas (Squamata: Boidae: Corallus). South American Journal of Herpetology 7:172-180.

Tucker Valley Bioblitz, Press Report

The following is from the Trinidad Express.


The Tucker Valley Bushmaster, Lachesis muta.


The small headed treefrog, Dendropsophs microcephala

From 3.15 p.m. on November 17 to 3.15 p.m. on Sunday November 18 the first ever BioBlitz in Trinidad and Tobago took place in Tucker Valley, Chaguaramas. There are two main purposes of a BioBlitz: to see what is living in a chosen site and then to educate the public about what is there.

More than 80 scientists, experts and nature enthusiasts turned up over the weekend to record as many different species of plants and animals as possible in 24 hours. On the Sunday, more than 200 members of the public came along to go on guided walks, to watch the scientists at work and to learn something from the various organisations taking part.


The event was organised by Mike Rutherford, the curator of the University of the West Indies Zoology Museum (UWIZM), with help from members of the Trinidad and Tobago Field Naturalists' Club (TTFNC) and the UWI Department of Life Sciences. First Citizens very generously sponsored the event through the TTFNC, which allowed the setting up of a base camp in the overflow car park of the Macqueripe Bay Beach Facility. Here, lights, tables, microscopes, guide books, computers and collecting and processing equipment were set up for the scientists to do their work. The Chaguaramas Development Authority gave permission for the event and provided the security, who kept an eye on the base camp throughout Saturday night.


The experts and their helpers had been organised into seven groups, each focusing on different species or habitats – birds, mammals, reptiles and amphibians, terrestrial invertebrates, plants, marine and freshwater. Each group had previously planned how to find and record their target species or survey their chosen habitat. They also had to engage the public at the base camp or by taking them on guided walks. Information stands by the Asa Wright Nature Centre, the Environmental Management Authority (EMA) Youth Ambassadors, the Ministry of Food Production/CAB International and the TTFNC informed the public about various environmental issues. The Zoological Society of Trinidad and Tobago was also there with their mobile zoo called the Zoo To You programme, which allowed people to get up close to a blue-and-yellow macaw, a tree porcupine, a wild hog, a manicou and several rabbits and tortoises, among others.


The Bird group included members of the TTFNC Bird Group, Asa Wright Nature Centre staff, and independent wildlife tour guides. Although spotting started on the Saturday, with some good records of night birds including a barn owl, the majority of the birding was conducted on Sunday morning. One group headed up Morne Catherine on the western side of Tucker Valley and had a very productive time, while another group, led by Courtenay Rooks and Kayman Sagar, took the eastern side of the valley. They headed up to the Tracking Station and back down through the Bamboo Cathedral along with the members of the public who had signed up for the guided walk. In total 97 different species of birds were seen or heard, including parrots, toucans, owls, hawks, hummingbirds, tanagers, trogons and manikins.


The Mammal group, which included Howard Nelson, Ellie Nelson, Luke Rostant and Darshan Narang, headed into the forests and set up mist nets to trap bats and Sherman traps to capture small mammals. Both types of traps leave the animals unharmed. The mist nets weren't too successful and so the bat numbers were low, but by checking the abandoned houses and bunkers in the valley they did manage to add a few species. They also heard and saw monkeys and agoutis and found signs of armadillo, but the highlight was the temporary capture of a Robinson's mouse opossum in one of the Sherman traps. In total, 12 different mammals were seen.


The Reptile & Amphibian group, which included American expert John Murphy and local specialist Adrian Hailey, started surveying on the Saturday afternoon and went on through the night using torches to spot snakes, lizards and frogs. They saw 17 reptiles and 12 frogs, although one of the reptile highlights was actually provided by another group, the Birders, who found a dead bushmaster (mapepire zanana) snake that had been run over on the road up to Morne Catherine. This attracted a lot of interest when it was displayed at the base camp, with many members of the public very curious to see the rarest venomous snake in Trinidad.


John Murphy and Howard Nelson led a combined Mammal, Reptile & Amphibian walk along the Edith Falls trail on the Sunday, where they saw some capuchin monkeys and a racer snake, along with some small frogs and lizards.


The Terrestrial Invertebrate group had several sub groups: Chris Starr looked for wasps, bees, ants and termites; Jo-Anne Sewlal did the spiders; Rakesh Bhukal had a large group of UWI students looking for scorpions at night-time using UV lights; Imran Khan and Kris Sookdeo noted the butterflies they saw and Mike Rutherford did the land snails. Chris Starr led the public walk along the trail from Macqueripe Bay to the golf course and showed people the variety of insects that can be found in the forest. Overall, they found 125 species, although there are still some that need further identification, including a possible new species of orb-weaving spider found by Sewlal.


The Freshwater group included Amy Deacon, Dawn Phillip, Raj Mahabir and Erin Mangal, who are all involved with the UWI Department of Life Sciences. They focused mainly on the Cuesa River where they used a variety of nets to sample for the fish, crustaceans, insects and worms that can be found in freshwater. The conditions weren't ideal as heavy rains from the week before meant the river was murky and flowing high, which made it more difficult to sample. However, by the Sunday the levels had dropped and Deacon was able to lead a guided walk along the river and members of the public saw many different plants and animals. In total they found 43 different species including guppies, damselflies, crayfish and freshwater snails.


The Marine group was led by Jahson Alemu, with help from members of the Trinidad and Tobago Eco Divers Club as well as many students from The UWI. They dove and snorkelled in Macqueripe Bay during the day and at night, and found a wide range of sea creatures. One of the highlights for some of the snorkellers was seeing a green turtle in the bay on the Sunday. As the Marine group couldn't do guided tours for the public due to safety reasons, it was better to bring the animals to them, so some of the smaller animals found were temporarily brought up to the base camp to be displayed in an aquarium. These included a juvenile French angelfish, a scorpionfish and several sea urchins and brittle stars. Despite the rather poor visibility underwater the group recorded 138 species of fish, corals, sponges, crustaceans and other invertebrates.


The Plant group was coordinated by Mike Oatham from UWI and had help from the National Herbarium. They headed out into the forests and collected samples of as many plants as they could carry before returning to the base camp and processing them late into Saturday night. Members of the Trinidad and Tobago Orchid Society came early on Sunday morning and recorded several species of orchids in the forests between Macqueripe Bay and the golf course. The rest of the day was taken up with the identification of the collected specimens, with the help of local plant expert Winston Johnson, and the guided walk. This was led by Rutherford who took members of the public on the trail to the old bunker behind the Samaan Park. At the end of the 24-hour period, 211 species of trees, shrubs, ferns and orchids had been identified.


The BioBlitz was also used as an opportunity to launch some brand-new publications. The TTFNC had their 2013 calendar, sponsored by First Citizens, which contained many beautiful photos of the wildlife and scenery of Trinidad and Tobago, and their Trinidad and Tobago Wildflower Guide, with photos of 100 commonly encountered flowering plants. Rutherford launched his Trinidad and Tobago Wildlife Guide, which contains detailed drawings of more than 200 mammals, birds, reptiles, frogs and insects. Both of the guides are pocket-sized and laminated, perfect to take on walks and should be available soon in all good bookstores.


Following the success of this first national BioBlitz, plans are already being made for a sequel next year, with possible sites including Arima Valley, Maracas Bay to El Tucuche, Aripo Savannahs and Charlotteville in Tobago.



Event in numbers and facts



Time to record species — 24 hours


Number of scientists and volunteers — 80


Number of members of the public taken on guided walks — 140


Number of animals recorded — 443


Number of plants recorded — 211


Total number of living organisms recorded — 654


Biggest recorded organism — Samaan tree


Smallest recorded organism — Diatom (a type of algae)



Number of species recorded by group:



Birds – 97


Mammals - 12


Reptile and Amphibian – 28


Freshwater – 43


Marine – 138


Terrestrial Invertebrates – 125


Plants – 211

Name Changes for T&T Snakes in the Genus Liophis

Erythrolamprus reginae. JCM

Using eight mitochondrial and nuclear genes Gazziotin et al. present a phylogenetic analysis of the New World snake family Dipsadidae that included 246 terminal taxa and 196 dipsadids. Two previously un-sampled dipsadid genera, Sordellina and Rhachidelus, were included in the analysis. The definitions of the genera, Erythrolamprus, Clelia, Hypsirhynchus, Philodryas and Phimophis, and the tribes Alsophiini, Echinantherini and Conophiini, were revised. In order to maintain monophyly, the genus Umbrivaga was synonymized with Erythrolamprus, and two new genera were erected to accommodate Phimophis iglesiasi and Clelia rustica, as well as closely related species. The West Indian genera Schwartzophis, Darlingtonia, Antillophis and Ocyophis were also resurrected.

This study impacts the Trinidad & Tobago fauna by moving all of the members of the genus Liophis to the genus Erythrolamprus. Thus, Trinidad & Tobago now have seven species in the genus Erythrolamprus, E. aescapulii, E. bizona,  E. cobella, E. melanotus, E. ocellatus, E. reginae, and E. sp from Tobago.

Citation
Grazziotin, F. G., Zaher, H., Murphy, R. W., Scrocchi, G., Benavides, M. A., Zhang, Y.-P. and Bonatto, S. L. (2012), Molecular phylogeny of the New World Dipsadidae (Serpentes: Colubroidea): a reappraisal. Cladistics, 28: 437–459.

Podcnemis unifilis on Manzanilla Beach

The following story is from Newsday - September 10, 2012

Beach goers at Manzanilla Beach were called into action last week, when they came across several turtles coming out of the water. At first glance, believing them to be the young of the sea turtles that nest on this beach from March to August, they attempted unsuccessfully to carry them back out to sea, only to realise that the turtles struggled to come back to shore.

On closer inspection though, the turtles seemed different, with a closer resemblance to the land tortoises. Not being able to identify the particular turtle, contact was made with employees of the nearby Nariva Estate for assistance. According to Michael James, Manager of the Estate and member of the Manatee Conservation Trust, this is not an isolated incident since every three to four years, turtles and other reptiles that are not indigenous to Trinidad, have been migrating to the coastline travelling on mats of water lilies or water hyacinth and large debris - like clumps of trees or uprooted whole trees.

President of the Zoological Society of Trinidad and Tobago, Gupte Lutchmedial who coincidentally was on site confirmed that this seemed to be an alien species and advised that it would be imprudent to release the surviving turtles into the Nariva Swamp, which may not be this turtle’s natural habitat. The live turtles were subsequently sent to the Emperor Valley Zoo for positive identification, and over 30 carcasses discovered among the beach debris were buried.

Nirmal Biptah, Curator of the Emperor Valley Zoo, recognised the turtles as Podocnemis unifilis, commonly known as yellow headed sidenecks, one of four existing South American species. The turtles found were full-grown adults and are fresh water, land-based species. As these fresh water turtles cannot survive in sea water, this would have accounted for the high level of mortality observed. Lutchmedial added, “Another cause of mortality to these turtles may be predation by the stray dogs that dwell on the beach front. While some were lucky to survive the journey atop the flotilla of vegetation and debris, others could not get past this danger.”

There is a debate on whether or not these species are indigenous to Trinidad. According to a local journal, Kearney (1972) states that they occur in Trinidad but are "confined to a small colony in Nariva Swamp." However, according to Hans Boos, the former curator of the Emperor Valley Zoo, and expert on Trinidad and Tobago’s reptiles species, he disputed this statement saying, "This species is not indigenous to Trinidad and there is a possibility that these species are from our neighbour, Venezuela."

A couple years ago, there was the arrival of some juvenile anacondas on “rafts” of water hyacinths at Icacos beach, around the same period. These rafts were propelled from the Orinoco River and its tributaries because of the heavy rainfall there.

There are reported instances of other reptiles and even mammals making landfall, including the capybara, giant otter and the Brazilian tapir. In this instance where the rafts reached all the way up to Manzanilla, Lutchmedial explained, “The debris may have been because of the dredging activities for gold along the Orinoco River where heavy rains and flooding caused the bank flora to collapse.”

One of the surviving turtles is on display at the Emperor Valley Zoo and is attracting the attention of patrons.

Notes on the Tobago Glassfrog, Hyalinobatrachium orientale

Two recent papers document male parental care in the Tobago glassfrog population. Murphy et al (2012) reported males attending nests while calling, presumably to attract more females to deposit more eggs. This past month we observed males attending up to three nests. Lehtinen and Georgiadis (2012) report males attending up to six egg masses. The eggs masses and calling males are frequently on the underside of leaves that overhang the water (see above). Our observations in the past month suggegst that glassfrogs are frequently using Heliconia leaves that overhang the water and that nests may be 1-4 meters above the water (see photo). In 2011, Murphy et al. observed small crabs on the same plants used by the frogs. Placing eggs on the underside of leaves may be a response to crab predation, since the crabs are unable to walk on the underside of leaves. However, the purpose of male attendance remains uncertain. Males covering egg masses may act to prevent dessication, but a male with six nests may find protecting all nests from drying quite difficult. Another possibility is that the male is transferring some molecule(s) to the eggs that are antifungal or antibacterial. The presence of the male may also prevent predation or parasite infection from insects. Twelve eggs masses examined by Lehtinen and Georgiadis (2012) had 21-36 eggs (mean = 28.3).  And, they found tadpoles capable of prpeling themselves up to 40 cm (or 36 times their body length). The distribution of these frogs on Tobago also seems to be more widespread than previously thought because we heard them calling from numerous stereams that drain the island's Main Ridge in all direstions.

Citations
Lehtinen R. M.and Georgiadis A,P. 2012. Observations on parental care in the glass frog Hyalinobatrachium orientale (Anura: Centrolenidae) from Tobago, with comments on its natural history. Phyllomedusa, 11(1):75-77.

Murphy, J.C., Charles, S., and Traub, J. 2012. Hyalinobatrachium orientale. Male parental care. Herpetological Review 43:118-119.

More Foam Nesting Frogs

Another species of frog we found in Lopinot Valley on Thursday morning was the Whistling Frog, Leptodactylus fuscus. Whistling frogs lay their eggs in foam nests within small burrows at locations that will flood with increased rainfall. Locating nests is tricky. But, Roger Downie has developed a technique that includes probing the soil with small sticks until a nest is found, removing the mud cover, and exposing the foam nest. Below is a photo of a whistling frog foam nest and an adult Leptodactylus fuscus. As rainfall increases, the nest will be covered with water and the tadpoles will escape into the pool, or be washed into a pool by runoff. Should the rains be delayed the tadpoles will stay in the nest and produce more foam (undoubtedly with a different chemical composition) to prevent desiccation and deter predators. Which is why Dr Paul Hoskisson is a microbiologist of Strathclyde University is here. Hoskisson is examining the structure of proteins in frog foam, both foam made by the parent frogs initially building the nest and the foam mad by the tadpoles.

The Foam Nest of the Tungara Frog

This morning a walk in Lopinot Valley produced several frog nests after last night's rain. Below is a photo of a nest made by the túngara frog, Engystomops pustulosus.  My companions were interested in studying the proteins involved in making these nests. So, here is some background on nest construction and function of the foam.

The widespread and abundant túngara frog, builds foam nest on the surface of small temporary pools of water in the Neotropics. The male collects eggs and foam precursor fluid from the female's cloaca with their feet, and create a rounded mound of foam incorporating pond water, the eggs, and proteins with a mixing action of their legs. Construction of the nest is a series of mixing events that takes about an hour. At first observation nest construction appears to be a simple process of regular, periodic bouts of egg release and foam production that should result in eggs being disorderedly distributed throughout the foam. But, Dalgetty and Kennedy (2010) showed the nesting process is sophisticated, occurs in three phases, and that the nests have a differentiated internal structure.

They found that a semi-dispersed raft of bubbles is produced initially, during which no eggs are released, followed by the appearance of a growing mound into which eggs are incorporated. The males keep their lungs inflated throughout the nesting process, and arch their spines considerably to accommodate the height of the nest as it enlarges. Time lapse filming revealed that they move regularly from side to side, probably to ensure the round mound shaping of the finished nest.

They measured the duration of each mixing for 16 nesting events, and found that mixings are initially short, but increase in duration linearly from about 1 second to a plateau of approximately 4.5 seconds which is then sustained with little variation until nest completion

The time between the beginnings of successive mixing events is irregular at first, but then becomes regular with intervals of about 14 seconds that are maintained throughout the main building phase. Towards the end of nesting, the time between mixings increases in an exponential-like manner until cessation, though the duration of mixings does not change.

When the frogs are disturbed (in the wild or in the laboratory) and leave the nest, they tend to return to it, reversing into their original position to resume construction. When disturbance occurs, the periods between mixing event beginnings are irregular but soon return approximately to the original periodicity.

Thus, they found nesting occurs in three discrete, overlapping phases. Phase 1 is characterized by the production of a bubble raft with no egg release and mixing events increasing in duration. Phase 2 is the main building phase, marked by both event duration and start-to-start intervals being roughly constant as the foam hemisphere develops. Phase 3 is the termination phase, when the duration of mixings does not change but the time between them increases in an exponential-like fashion to cessation of the construction.

Túngara frogs may build nest colonially so that many nests are laid in contact with one another, but the eggs and foam are not co-mixed. Vertical cross sections of nests show eggs concentrated close to the base in the core of the nest, with a distinct cortex of egg-free foam about 1 cm deep. When a completed nest is placed on a dry surface, mimicking post-spawning drying of the nesting pond, tadpoles descend to the base of the nest and remain confined to its core, and do not breach the egg-free cortex despite the core's foam becoming liquefied, and the authors found the larvae can communicate between the cores of two nests that are in contact without breaching the protective cortex.

The advantages to the egg-free cortexseem to include protecting the eggs from dehydration by distancing them from exposure to air; shielding the eggs from light damage; and the cortex reduces access to the eggs and tadpoles by predators or parasites. The advantages of colonial nesting may be a decreased in the surface to volume ratio, and thus a reduction in the evaporative water loss. Also, joining a nesting already in progress allows exploitation of a pre-existing bubble raft and thus saving of nest material, energy expenditure and time exposed to possible predators.

Citation
Laura Dalgetty and Malcolm W. Kennedy. 2010. Building a home from foam—túngara frog foam nest architecture and three-phase construction process. Biology Letters doi:10.1098/rsbl.2009.0934

TTFNC Presentation: An Update on the T&T Herpetofauna

Roger Downie and I will be giving an update on the T&T herpetofauna on this topic on June 14 at the TTFNC meeting in Port of Spain. Check the TTFNC website for time and location. My presentation will include a discussion of cryptic species.  The evidence is mounting for T&T holding numerous cryptic species of frogs, lizards and snakes. In some cases these are species thought to be widespread and known to be present on the islands for a long time, but we are just realizing they are different from mainland populations. In other cases there are multiple cryptic species present in the islands that were previously thought just one species.

Forest snakes in decline in Trinidad?

The following story is from the Trinidad Express Newspapers. The common name mapepire balsain refers to Bothrops sp., mapepire zanana refers to Lachesis muta.

...Plenty mapepire balsain, but no zanana

Story Created: May 2, 2012 at 10:57 PM ECT

Those who traverse the mountains of our ranges will no doubt tell stories of how they learned to survive in an environment that is totally the domain of silent creeping and climbing creatures.

Stories of huntsmen finding reptiles snuggled in their bunks in camp, some finding them camouflaged amid leaf debris, some set to ambush along the trails, some hanging from overhanging branches and others swimming across streams.

Each story will tell of at least one reptile that felt threatened and retaliated in defence of its safety.

One Madamas huntsman got bitten on his hand when he used it to hoist himself up onto the riverbank. Another narrowly missed sleeping with one as his companion in camp when he was too tired to shake out his blanket before covering with it. There are those men who were actually bitten by poisonous species but had the survival techniques to overcome the effects of the venom. Each of these experiences has been with the mapepire balsain or zanana.

Last weekend, our outfit had not only one tale to tell of narrowly being bitten by a mapepire but of being under constant threat from numerous of the species set across a vast area of the north eastern Northern Range.

The mapepire balsain (bothrops atrox) is one of four venomous snakes found in Trinidad. It is a master of camouflage as it lies in wait amid the leaf debris carpeting the forest floor.

Our first encounter was set in ambush for its unsuspecting prey.

Though this one was a baby, it was just as dangerous as the grown ones, set as it was on the forest floor.

Our second was about seven feet long when it showed its length during a hasty retreat down the hill.

We managed to get more of them out of the way by either diverting them downhill or passing as far as possible from them.

The ninth or tenth balsain was a bit more stubborn, holding its ground despite our attempts to relocate it.

This was the one that actually attacked Ronald's boot.

Hssss… and Ronald was up in the air, landing some way down the hill.

Luckily there was the warning sound that caused him to jump out of harm's way. Luckily also, he wore a pair of boots, a must especially around these months of mating season of the species.

Marking the balsain's location, we cut a detour for our safe return passage.

They were really out in their numbers last weekend. What was most disturbing to us, however, was the total absence of the mapepire zanana or bush master. This species seems to have been on the decline for some time.

We know that these species are forced out of their domain by the encroachment of humans into their territory. They are not allowed to retreat into the forest, but are killed.

Talking to Allan Rodriguez, popularly known as "the original snake man", he, too, was disturbed about the obvious scarcity of the mapepire zanana in our forests.

"You have to blame the commercial hunters for this. They hunt for what they want and kill everything else that comes along their path. We must remember that the mapepire zanana is an egg layer. It lays at least 12 eggs and out of these 12, only six will hatch young safely. The balsain, on the other hand, delivers live young. This puts the mortality of the zanana at high risk.

"Something has to be done about this indiscriminate decimation of our reptilian species. Had it not been for their presence, we would not have had a balance of species in our forests.

Each reptile, and that includes the zanana, is a valuable part of the web of life to which we belong."

A Correction on the name for the Trinidad & Tobago Oxyrhopus

Oxyrhopus petolarius, JCM

In zoology, the Principle of Priority is one of the guiding principles of the International Code of Zoological Nomenclature, and is defined by Article 23.

It states that the correct formal scientific name for an animal taxon, the name that is to be used,  the valid name, is the oldest available name that applies to it. There are exceptions; another name may be given precedence by any provision of the Code or by any ruling of the Commission.

This is one of the fundamental guiding precept that preserves the stability of zoological nomenclature. It was first formulated in 1842 by a committee appointed by the British Association to consider the rules of zoological nomenclature; the committee's report was written by Hugh Edwin Strickland.

Two available Linnean names from1758 and two from 1766 are based on snakes of a single species of Oxyrhopus. Which of these names has priority has been unclear. A review of the history of these names establishes Oxyrhopus petolarius (Linné, 1758) as the correct name for the species because of the actions of Lönnberg (1896) the first reviser of O. petolarius.

Citation
Savage, JM. 2011. The correct species-group name for an Oxyrhopus (Squamata: Dipsadidae) variously called Coluber petalarius, C. pethola, C. petola, or C. petolarius by early authors. Biological Society of Washington 124:223-225.