Showing posts with label Trinidad. Show all posts
Showing posts with label Trinidad. Show all posts

Monday, July 11, 2011

The Herpetofauna of Trinidad and Tobago Website

The website Herpetofauna of Trinidad and Tobago and associated blog are now functional. However, the website is a work in progress and needs photos and text. If you can help with that please contact us. JCM

Friday, June 24, 2011

Trinidad's Snail-eating Snake

The Snail-eating Snake, Dipsas trinitatis. This specimen was found
crossing the Arima Valley Road.
H. W. Parker described Dipsas trinitatis from a single specimen collected in Trinity Hill Reserve, Trinidad in 1926 and recognized its close relationship to the Venezuelan D. variegata. He distinguished the two species on the basis of presence or absence of a preocular, the number of upper labials, and differences in color pattern. In 1960 James Peters recognized trinitatis as a subspecies of D. variegata based solely on color. Cadle et al. (2003) showed the two forms are similar in scale counts and color pattern and note that D. v. trinitatis has a smaller head in relation to the body and fewer maxillary teeth than does D. v. variegata, but considered the Trinidad population a subspecies of D. variegata. Dipsas trinitatis was removed from the synonymy of Dipsas variegata by Harvey and Embret (2008) on the basis of distinctive morphology and its allopatric distribution. D. trinitatis can be distinguished from D. variegata by fewer (7-9) maxillary teeth, the lack of sublabials (scales between the labials and chin shields), and the lower labials contact the third pair of chin shields on one or both sides of all specimens. Specimens with two pairs of chin shields the lower labials contact the fused single scale where the third pair would be. Emsley (1977) suggested that its apparent rarity was due to its crepuscular activity and cryptic habits. I observed this snake relatively frequently in the Arima Valley and occasionally at other locations on the island in the 1980’s, but failed to find it during several  trips made ten years later. On my current trip a specimen of the snake was encountered during a heavy rain storm, about 0100 hours in the Arima Valley (photo). Friends report that they see this snake in low bushes in the early evening, probably hunting snails.

Monday, June 20, 2011

Aripo Savanna & its Herpetofauna

Trinidad’s Aripo Savanna complex of tropical grasslands, palm islands, marsh forest and moriche palms with numerous slow moving streams, ponds, and puddles. On June 18-19 the Herp Group from the Trinidad and Tobago field Naturalists Club surveyed the herpetofauna. The weather cooperated to a degree with occasional showers and thunderstorms and blistering heat, which creates a very nice sauna-like effect. The TTFNC-HC will summarize the results elsewhere, but here are a few of the highlights.
Rare creatures are sometimes sited on the savanna. Here is Graham White looking 
for them while well camoflaged.

Aripo Savnna 1. The largest remaining remanant of the savanna.

Stevland Charles and Edmund Charles inspect Marsh Forest Vegetation
A Marsh Forest Pond
An Aripo Savanna Sundew.
Leptodactylus fuscus, the most commonly seen and heard amphibian on the Savanna,
The Scorpion Mud Turtle, Kinosternon scorpioides, a savanna and marsh
 forest inhabitat.
The Trinidad Wood Turtle, or Galup, Rhinoclemmys punctularia, another Marsh
Forest - Savanna chelonian.

Predator & prey. The Horse Whip Snake, Oxybelis aeneus and 
 its prey, the Streaked Lizard, Gonatodes vittatus.
A male Hypsiboans punctata (Hylidae) that was calling from this leaf.
The poorly known microhylid frog, Elachistocleis surinamensis
 is quite common  in the Marsh Forest and at the forest edge.

One of the day groups, with Mike Rutherford examining a turtle (middle).

Wednesday, June 15, 2011

Looking For Squamates in the Bocas

Between working in the UWITT Museum and running around Trinidad to find supplies we do occasionally get into the field for some serious collecting and fun. On Tuesday, Stevland Charles, Mike Rutherford, and Josh Traub, and I visited two of the Bocas Islands – Gaspar Grande and Monos  - the major goal was to find more coral snakes from each of the islands. However, snakes are notoriously difficult to find no matter how much ground cover you turn. Keeping that in mind we hoped to at least add some footnotes to the islands’ herpetology, and collect some specimens that could supply tissue for molecular studies. Mike was also interested in adding land snails to the UWITT collection. The Bocas Islands (Bocas del Dragon) lie between Trinidad and Venezuela, in the  “Dragons' Mouth”.
Our first stop was Gaspar Grande, a small island composed mostly of limestone. After exiting the boat and a short hike we were at the opening of a sinkhole that descended into a cave; local people had used this as a dump. Using a rope all of us were soon exploring the sink and collecting land snails for Mike and Gonatodes for Stevland. 
Mike and Josh looking for snails in the sinkhole on Gaspar Grande.
Leaf-nosed bats would occasionally brush us. Out of the hole and walking up the trail Gymnopthalmus and Ameiva were quickly getting out of our way. At the top of the  hill were  several relicts of World War II, anti-aircraft gun emplacements, now covered with graffiti and inhabited by some of the island’s lizards. Despite several hours of looking we collected only Gymnopthalmus, a Gonatodes vittatus, and some snails.
We met the boatman at noon and headed for Monos, just a few minutes away.
Stevland directing the boatman to the landing site.
 Landing on Monos, was a bit tricky, the boatman let us off on a crumbling concrete wall several hundred feet from shore. The required us to scramble over slippery, broken concrete to reach shore. As we approached the beach the volume of plastic litter and other man-made junk was alarming. Stevland had been to this location before, and we walked through the coastal palms in to a more seasonal dry forest to a house. As if he knew where to look - an outhouse- Stevland produced a Hemidactylus palichthus within a minute of arrival. This gecko's presence in the Western Hemisphere is a biogeographical puzzle, all of its close living relatives are in Africa, and it is the only Western Hemisphere Hemidactylus that is endemic. All other Western Hemisphere Hemidactylus are  introduced.  
The gecko, Hemidactylus palichthius.

We walked along a stream bed only to encounter a large bamboo die-off that made following the gully exceptionally difficult. As we got deeper into the forest Plica plica became more obvious and abundant, these arboreal and scansorial tropidurid lizards are quite social and on some of the larger tree trunks 3 or 4 individuals were obvious. 

Josh  with a Plica plica on the tree buttress.

Monos has a large amount of human made garbage washing up on its beaches.

Snakes eluded us until we got out of the gully onto the hillside, within a few minutes a Mastigodryas was spotted, but despite being in contact with the hands of two of us it escaped. As we headed back to the beach Mike spotted a Boa constrictor laid out along a broken palm frond. It was a male, about 1.3 m long and had two blood swollen ticks attached to its head. 

Boa constrictor with ticks.

Boa constrictor after tick removal.
After removing the ticks, and a photo session, we were out of water and it was time to met the boatman for the return trip to Trinidad. Despite the fact that we did not find any Bocas coral snakes, the day was not a total loss.