Have you been hearing an odd animal noise in your home at night? It's probably a gecko

House gecko (Hemidactylus mabouia). Photo by John Murphy

For those of you living in Trinidad and Tobago, you may have heard an odd sound coming from your wall or roof at night. Chances are, it was an African House gecko (Hemidactylus mabouia).

Other common names include African wood-slave and twenty-four hours. (NB: A few different lizards are referred to as 24-hours in Trinidad, whereby when the lizard falls on you, you have 24-hours left to live - a common folklore in the country).

Here is a YouTube Link to what these geckos sound like: https://www.youtube.com/watch?v=7dP33YLo-KU (1 minute long, but can skip to 25 seconds). Have you heard this sound in your home? Let us know!

You can learn more about this lizard and the folklore of local reptiles in the "Field guide to the amphibians and reptiles of Trinidad and Tobago" available in most leading bookstores nationwide, or directly from the Trinidad and Tobago Field Naturalists' Club.

Hurricanes and Anolis lizards of the Caribbean

Leaf anole (Anolis planiceps) gripping onto a plant. Photo by Renoir Auguste

Hurricanes are a constant threat to all across the Caribbean and they are getting more severe because of climate change. Hurricanes not only have devastating effects on humans, but also animals as well. For example, the white-tailed sabrewing hummingbird was almost extirpated from Tobago after hurricane Flora passed over the island in 1963.

Some animals have shown the propensity to adapt to severe hurricane winds, allowing them to survive. One adept example can be seen in Anolis lizards or Anoles, which can be found on every Caribbean island.

Anoles are mostly small to semi-large lizards. They are found across the Caribbean and Americas and are important components of ecosystems, feeding on a variety of insects, and are food to a variety of birds and other animals. They are considered ideal organisms for studying biology, ecology, and adaptation (among other fields).

A study by Donihue et al. 2020 showed that Anoles have found a way to adapt to strong hurricane winds: by growing larger toepads! These toepads allow the small lizards to grip onto vegetation better, thus allowing them to not be blown away by strong winds. Not only are these lizards with larger toepads surviving hurricanes, for example hurricane Irma and Maria from 2017, their offspring are being born with large toepads as well (compared to other anoles not exposed to hurricanes).

It's amazing what we can learn from animals, such as anoles, about adaptation to global events. No doubt we can learn more from them, which hopefully will allow us to appreciate them more and improve our management of biodiversity conservation.

There are at least 8 types of Anoles in Trinidad and Tobago. To learn more about these Anoles found in T&T, do get yourself a copy of the field guide to the amphibians and reptiles of Trinidad and Tobago, available from the Trinidad and Tobago Field Naturalists' Club.

Why Glass Frogs have see through skin

Tobago Glass Frog (Hyalinobatrachium orientale tobagoense) seen from below - translucent. Photo by Renoir Auguste

Animals with transparent skin in nature are rare, and our understanding of the function of it is even rarer. One example of an animal with apparent transparent skin is the glass frog. They are found across Central and South America, as well as on the island of Tobago, north east of Venezuela. These frogs, as their name suggests, have skin where the organs, bones, and even eggs (in females) can be seen through their skin. However, only from their underside, and not their back (as seen in both photos in this post). Because of this, glass frogs are better defined as being translucent due to the dorsal pigmentation.

Scientists investigated whether the imperfect transparency (only the belly and not the back) acts as camouflage, and how effective it is. They found that the perceived luminance of the glass frogs changed depending on the background, which lowered detectability by predators, and increased survival, when compared to opaque (not able to see through) frogs. It also appears that the change was greatest for the legs, which surround the body at rest which hid the frogs even more, referred to as edge diffusion. No doubt this is probably why glass frogs are so difficult to find during the day when they are sleeping!

The Tobago Glass Frog shares these similar translucent features of other glass frogs across the region. To learn more about the local glass frogs in Tobago, including where to find them, check out the Field guide to the amphibians and reptiles of Trinidad and Tobago, available by the Trinidad and Tobago Field Naturalists' Club.

Tobago Glass Frog seen from above - not translucent. Photo by Renoir Auguste

Reference: Barnett et al. 2020. Imperfect transparency and camouflage in glass frogs. PNAS.

Venomous vs Poisonous difference examples using Trinidad herpetofauna

Figure and photos by Renoir Auguste.
On the left top & bottom: Cane Toad (Rhinella marina)
On the right top: Mapepire Balsain or fer-de-lance (Bothrops atrox)
On the right bottom: large coral snake (Micrurus diutius)
All species were photographed in Trinidad.

A lizard pretending it is dead while being photographed

Trinidad hex-scaled lizard pretending to be dead while being photographed. Photo by Renoir Auguste

Death feigning (thanatosis) is an adaptive defensive behaviour seen in various animals, perhaps quite famously associated with opossums, but it has also been recorded in a variety of herpetofauna, including frogs, snakes and lizards.

A local example can be found here in Trinidad and Tobago with the hex-scaled lizard (Bachia trinitatis). This small (~ 6cm long) fossorial lizard is found in Trinidad and Tobago, mainly in leaf litter. Sometimes the small limbs may make persons confused this lizard for a worm.

In June 2016, one such individual was caught and brought back for closer inspection to photograph. While photographing it, the lizard rolled over to its side and pretended to be dead. After a couple minutes, and with the camera not too close, it put itself back upright. 

This may be the first documentation for this species exhibiting death feigning behaviour and it can be found here in Trinidad and Tobago. For more information about this lizard and other interesting facts about local wildlife, be sure to check out " A field guide to the amphibians and reptiles of Trinidad and Tobago". 

Source of information:

§  Auguste, R.J. 2019. Natural History Notes: Bachia trinitatis (Trinidad hex-scaled bachia). Defensive behavior. Herpetological Review 50(3):570.

Trinidad hex-scaled lizard (Bachia trinitatis) not playing dead. Photo Renoir Auguste

Trinidad's two types of Caiman

Spectacled caiman (with eye shine) from the Caroni Swamp. Photo by Renoir Auguste

Trinidad and Tobago has two species of caimans. The spectacled caiman (Caiman crocodilus). and the Cuvier's dwarf caiman (Paleosuchus palpebrosus). The following are some traits about each type of caiman and how to tell them apart.

Spectacled caiman

• Typically grows to up to 2.3 m long. 
• Males are larger than females. 
• This species is widely distributed across the region, from Central America, to South America, and Trinidad and Tobago. 
• They typically reside in brackish and freshwater environments and can be easily seen at night in swamps with their eye shine. 
• Juveniles feed on aquatic invertebrates whereas adults feed on vertebrates such as fish, amphibians, birds, reptiles, and mammals. 
• Juveniles do have a distress call and parental care is noted in crocodilians.
• One of the key distinguishing features to tell the spectacled caiman apart from other caiman in the country is the bony ridge on the head behind the eyes.

Dwarf caiman

• Typically grows to about 1.5 m long.
• Males are slightly larger than females.
• Distribution range is South American.
• Habitat preference is for fast flowing streams in forests in cooler areas, compared to more open areas used by spectacled caimans.
• Juveniles feed on insects, fish, frogs, whereas adults also feed on these but would include mammals to their diet.
• Dwarf caimans are social and dominant individuals would have access to mates, food, nest sites.
• Upper and lower jaw has dark and light spots. Also, the lack of a bony ridge anterior to the eyes distinguishes it from the spectacled caiman.

Dwarf caiman. Source: Wikipedia.

Source of information:

• A field guide to the amphibians and reptiles of Trinidad and Tobago. Published by the Trinidad and Tobago Field Naturalists' Club. 
• Ali SH, Rampersad-Ali N, Murphy JC. 2016. The discovery of Cuvier’s Dwarf Caiman, Paleosuchus palpebrosus (Reptilia: Alligatoridae) in Trinidad. Living World, Journal of the Trinidad and Tobago Field Naturalists' Club. 2016 Nov 30.

The Bushmaster/Mapepire Zanana (Lachesis Muta), A Unique and Highly Specialized Pit-Viper Living In Trinidad’s Forests

Lachesis muta (Mapepire Zanana or Bushmaster) in-situation and in habitat  

(Photo by Rainer Deo)

           Strewn across the globe are highly venomous snakes that stand out to herpetologists and civilians alike. Some of these include the King Cobra from Asia (the largest venomous snake in the world), the Black Mamba from Africa (considered the fastest snake in the world), the Inland Taipan from Australia (the most venomous terrestrial snake in the world) and the Atlantic Bushmaster, locally known as Mapepire Zanana, from South America (the largest pit-viper in the world). Only two viper species can be found in Trinidad and it should be said with pride, that the Bushmaster is one of them.

What makes the Bushmaster such a unique and highly specialized snake?

1.        Oviparous (Egg-laying): When compared to close relatives, such as the Mapepire balsain (Bothrops cf), Bushmasters stand out as being the only documented genus of new world pit-vipers to lay eggs, as opposed to retaining eggs and giving “live birth” (ovoviviparity). The mother lays her eggs in the burrows created by agouti, lappe and armadillos or in holes under the buttress roots of trees such as the Mora (Mora excelsa). She coils around them to provide insulation, since their habitat is usually very cool and courageously guards them until they hatch.

2.        Big snake, small prey: It is typically believed that the larger a snake grows, the larger the prey it would hunt and be able to consume. This however, is not applicable to a number of groups, including the Bushmasters. They are known to feed primarily on small forest mammals with the Trinidad spiny-rat being one of their favourite local preys. Inexperienced keepers would be left baffled when a large Bushmaster (8-10 ft long) would bite and kill a rat but refused to eat it because it was simply too big.

3.        Intolerant of hot environments: It might be assumed that it is typically always warm and sunny in the tropics. However, Bushmasters are found most frequently in the hilly and mountainous areas of Trinidad where the environment gets very moist and cool. Deep within some of Trinidad’s forests, nights and early mornings may have temperatures that drop to as low as 19 degrees Celsius. These wet and cold conditions are essential for the survival of the Bushmaster which can accommodate multiple small prey in its lengthy body. If the environment and the snake become too warm, bacteria found within its prey would begin to multiply rapidly, resulting in the poisoning and almost certain death of the snake.

4.        Fossorial (Burrowers): Bushmasters are semi-fossorial which means they spend a significant amount of time underground in holes and burrows. In Trinidad, the Bushmaster is referred to as Mapepire Zanana, a name with French Creole and Carib origins. It translates to “Pineapple snake”, an appropriate comparison considering how bumpy and serrated some of the scales are. The roughness of the skin is an evolutionary feature which aids the snake in excavating its burrows. 

Closer look at scales on the Bushmaster. Photo by Rainer Deo

To learn more about the Bushmaster or other snakes in Trinidad, feel free to contact the Trinidad and Tobago Field Naturalists’Club (TTFNC) Herpetology Group, and get yourself a copy of the field guide to the amphibians and reptiles of Trinidad and Tobago – published by the TTFNC!

This post was written by Rainer Deo – TTFNC Herpetology Group member.

T&T Lizard, Frog, Snake, Turtle, Caiman Identification and Awareness

Beebe toad in hand. Photo by R. Auguste

Chances are you have come across a lizard, snake, turtle, caiman, &/or frog at some point in time while living here in Trinidad and Tobago. However, you either have been told what the local name is, or sometimes you do not know. But you are curious. You want to know.

However for most people, they dislike frogs and reptiles, and rather not know. Yet, there are some that do and it is always beneficial to know about them, even if you dislike them. Perhaps you know someone who is, or your child is fascinated with frogs and reptiles despite your feelings towards them. However, for most, (maybe you) you have already convinced yourself that you will never change your mind about liking snakes, lizards, and/or frogs. OK - but maybe your child does like them. Your child wants to learn more about them. It helps them be more creative with their school work giving a local real example. It also helps build national pride in our native fauna.

If that is the case, you can reach out to us (Trinidad and Tobago Field Naturalists' Club) anytime for information on local frogs and reptiles. Whether it is simply asking for an identification, or perhaps you want to know some quick facts about them - what does it eat? is it poisonous/venomous?  how beneficial is it to me, society, economy and the environment? You'd be surprised that frogs and reptiles offer economic and social benefits to people! We also carry out field trips annually to locations across the country to look for reptiles and frogs and photograph them. Beneficial to persons interested in seeing them in their natural habitat and learning how to identify them.

If you are a parent or teacher, then you can get a copy of the field guide to the amphibians and reptiles of Trinidad and Tobago. Appropriate for all ages. Young children can enjoy the colourful photographs, whereas older ones and young adults can read up on the scientific information, which also includes folklore details and habitat information.

The more children learn and appreciate animals around us, the better society, economy and the environment will prevail for all.

Harmless mangrove snake (non-venomous) on hand. Photo by R. Auguste

Amphibians of Trinidad and Tobago: 10 Facts

Tobago glass frog. Photo by Renoir Auguste

The amphibians of Trinidad and Tobago all comprise Anurans, or frogs and toads. There are 35 recognized species (currently), and they are all diverse in size, colour, and distribution.

1. The largest amphibian in the country is the marine/cane toad (Rhinella marina), locally known as crapaud. This is the only poisonous frog found within the country.
2. The smallest frog in the country is the miniscule tree frog (Dendropsophus minusculus). This species is restricted to south west Trinidad.
3. The polka-dot tree frog (Boana punctata) glows in the dark under UV light.
4. The paradoxical frog (Pseudis paradoxa) has tadpoles that are twice as large as the adults, hence the common name paradox. The chemical properties in the skin of this frog has been used for treatments in human diseases; diabetes.

Paradoxical frog. Photo by Renoir Auguste

5. The Tobago glass frog (Hyalinobatrachium orientale tobagoense) is a subspecies specific to north east Tobago, and it got its common name from the fact that the skin on the belly is transparent, allowing an observer to see its internal organs!
6. The golden tree frog (Phytotriades auratus) is found only in tank bromliads across the highest peaks in Trinidad (and Venezuela). This species is considered critically endangered because of its restricted range, and vulnerability to threats such as climate change and habitat loss.
7. The Trinidad stream frog is endemic to Trinidad - found no where else in the world! In this species, the male protects the young tadpoles and even carries them on his back (see photograph below).

Trinidad stream frog. Photo by Renoir Auguste

8. The village of Charlotteville, in north east Tobago has a species of frog named after it - the Charlotteville litter frog (Pristimantis charlottevillensis).
9. There is currently one species of invasive/non-native species of frog in the country - the Johnstone litter frog (Eleutherodactylus johnstonei). Persons especially living in the north west would hear this frog calling in their garden. It is restricted to urban areas and currently does not pose any threats to the local endemics. However with increased urbanization and encroachment of forests, this may soon change.
10. Amphibians act as indicators to environmental change because of their sensitivity to microclimate. As such, the fewer frogs we are seeing and/or hearing in our country would mean that there is something drastically wrong with the environment. This not only has negative effects on local frog populations, but other wildlife and humans as well. A degrading environment is bad for all, and we should put more effort into protecting it, for us and for future generations to come.

To learn more about the amphibians of Trinidad and Tobago - get yourself a copy of the field guide to the amphibians and reptiles of T&T. A great resource for students, naturalists, and scientists. Contact the Trinidad and Tobago Field Naturalists' Club for details.

Emerald eyed tree frog. Photo by Renoir Auguste.

Lizards of Trinidad and Tobago: 10 Facts

Leaf anole (Anolis planiceps). Photo by Renoir Auguste

Trinidad and Tobago has a spectacular diversity of lizards in the country. The field guide to the amphibians and reptiles of Trinidad and Tobago has much more information on them, but here are ten facts (at time of writing) about lizards in the country.

1. Two lizards can be legally hunted for human consumption during a stipulated time period: the green iguana (Iguana iguana) and the matte or crytpic tegu (Tupinambis cryptus).

2. The Family or group of closely related lizards with the most species on both islands is the Anoles, with at least 6 non-native introduced species, and at least one native species with a wide ranging distribution across Trinidad (Anolis planiceps). It is highly suspected that these are minimum estimates for this group, which is no surprise as Anoles are known to establish themselves across the Caribbean. In Tobago, the most widespread is the Guamangala or Richard's Anole (Anolis richardii) and on Trinidad the bronze anole (Anolis aeneus) is perhaps the most widespread of the non-native species.

3. The smallest type of lizard in the country is the Mole's dwarf gecko (Sphaerodactylus molei) which grows to less than 3 cm long fully grown.

4. The largest type of lizard in the country is the green iguana which grows to up to 2 m long.

5. There are two species of legless lizards on Trinidad: the double-headed worm lizard or white legless lizard (Amphisbaena alba) and the black and white worm lizard (Amphisbaena fuliginosa). Both are often confused for snakes or worms, but are in fact much more aligned with lizards.

Green iguana (Iguana iguana). Photo by Renoir Auguste

6. There is a shiny lizard that is all female and reproduces without the assistance of males (Gymnophthalmus underwoodi).

7. The luminous lizard (Oreosaurus shrevei) is known only from Trinidad.

8. The ocellated gecko (Gonatodes ocellatus) is known only from Tobago and its offshore islands.

Ocellated gecko (Gonatodes ocellatus). Photo by Renoir Auguste

9. Most lizards in the country are predominantly active during the day, with a few gecko species such as the turnip-tailed gecko Thecadactylus rapicauda, active at night.

10. Lizards comprise an important part of ecosystems and local human culture: they are predators to many insects we despise, and are known to be feared because of folklore tales, with one example being the "24 hour lizard, that if it falls on you, you have 24 hours left"!

Reptiles and Amphibians from Central Trinidad

High woods (false) coral snake. Photo by Rainer Deo

The eight annual Trinidad and Tobago Bioblitz took place at Tabaquite, central Trinidad on November 2nd to 3rd 2019. The event was organized by the Trinidad and Tobago Field Naturalists' Club (TTFNC) along with support and help from The University of the West Indies Life Sciences Department. TTFNC President organized the herpetology group enthusiasts (and co-organized the event itself) and Club member Rainer lead the survey teams during the night to search for herpetofauna.

Cat-eyed snake predating on a treefrog. Photo by Adam Fifi

Over the course of the weekend, the herpetology team observed approximately 50 species of reptiles and amphibians. Some of the highlights included the rare high woods (false) coral snake (Erythrolamprus zweifeli), including both colour morphs, the elusive rain lizard (Kentropyx striata), the Trinidad stream frog (Mannophryne trinitatis) - Trinidad's only endemic frog, and possibly all three species of native freshwater turtle species! A very impressive haul over the course of the weekend and special thanks to all the volunteers and everyone else that made it possible! Where will the next T&T Bioblitz take place and what would we come across then?

Spot-nosed gecko. Photo by Renoir Auguste

There is increasing evidence that the Trinidad and Tobago herpetofauna are changing, with new species being recorded, either to the country from afar, or to science! Bioblitz represents an important way for citizens to participate and learn about biodiversity recording and conservation through active participation. Anyone can be a part of Bioblitz.

To learn more about the local reptiles and amphibians of Trinidad and Tobago, including how you as a citizen can identify them yourself, check out the field guide to the amphibians and reptiles of T&T (see more details on where to get the book here or contact the Trinidad and Tobago Field Naturalists' Club).

Polka-dot treefrog. Photo by Rainer Deo

Trinidad leaf-nesting frog. Photo by Adam Fifi

The UWI Zoology Museum's contribution to T&T Herpetology

UWIZM logo. Image courtesy the Department of Life Sciences, UWI

This post is dedicated to the outgoing  University of the West Indies Zoology Museum (UWIZM) Curator: Mike Rutherford.

Mike is on his way back home to Scotland having spent a decade in Trinidad and Tobago. During that time, he made great strides to enhancing the University's zoological collection. The importance of the work he did with zoological collections cannot be understated more than enough. And of course, some of the zoological records in the museum include amphibians and reptiles. The following are five out of many positive contributions UWIZM has made to T&T Herpetology.

1)
The UWIZM logo is of the Trinidad golden tree frog! A great way to raise awareness about this Critically Endangered frog.

2)
There are hundreds of amphibian specimens and over a thousand reptile specimens in UWIZM. Specimens date back to the 1950s and 1960s, and even some before then! Some of these can of course be seen on the global biodiversity information facility website (gbif.org). Having these records on GBIF is another way to improve biodiversity data accessibility in Trinidad and Tobago, something we all need to strive for to help tackle conservation issues that affect us all.

3)
Through a great collaborative relationship with visiting herpetologists from across the world, Mike has enabled research to be published using UWIZM specimens. This of course gives good publicity to The UWI and can be a way to strengthen university collaboration.

4)
Whenever UWIZM would have outreach events, more often than not some of the specimens on display would be reptiles and amphibians. Using reptile and amphibian specimens is another way to educate people about their importance not only to ecosystems and the environment but to people. This is especially the case when some people are either afraid of snakes, frogs and lizards, or out right despise them! The hope here is that people can take a couple minutes to hear about them and why they are important and hopefully one by one, people are more inclined to tolerating them at the very least.

5)
A few years ago, Mike and UWIZM organized the very first Bioblitz in the country. It offered a fantastic opportunity for passionate persons to join in with experts and learn more about the species they love. One example was with myself. It was at the first Bioblitz I got to meet John Murphy, an experienced herpetologist. From there, I never looked back and took on herpetology as my passion.

We hope the UWIZM will continue to prosper in the near to long term future for herpetofauna conservation and education for generations to come!

Thanks, Mike!

Mike speaking to school children about some specimens from UWIZM. Photo courtesy Department of Life Sciences