Monday, May 14, 2012

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.

Friday, May 4, 2012

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.

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.