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

The Pipa pipa: Have you seen this frog in Trinidad?

The Suriname toad (Pipa pipa) is perhaps one of the most bizarre looking frogs in Trinidad. This frog is predominantly aquatic inhabiting muddy bottoms of rivers. They feed on aquatic invertebrates and fish and use their star-shaped fingers which have filamentous tactile organs to detect food. During courtship the male fertilizes the eggs and then positions them so they attach to the female's back. The skin of the female grows around the fertilized eggs and the embryos develop with the females skin. They hatch after 90-120 days of incubation as miniature adults, about 20 mm in length. On Trinidad all of the records are from the southern portion of the island. When last have you seen this frog in Trinidad? Do let us know so we can help update its distribution on the island.

Pipa pipa  mother with young frogs on her back. Photo from The American Museum of Natural History

5 reasons Trinbagonians should appreciate snakes and why

Micrurus diutius - Large coral snake, Trinidad. Photo by Renoir Auguste

If you ask most Trinbagonians what they think about snakes, more often than not it seems the response is either instantaneous fear or hate. And yet, there are those who do like them, and appreciate their existence. Those of us who do appreciate snakes would try our best to convince others about their importance, but many times are seemingly ignored. In order to highlight world snake day, here are five reasons Trinbagonians should appreciate snakes and why.

1. Predators and pest removers. Snakes are important predators feeding on a variety of animals. They also feed on pests, including rats, snails, slugs, insects, and parrots (all of which can have negative effects on crops). In addition, some snakes even eat other snakes, particularly the venomous ones!

2. Research and Medicine. Studies on snakes have shown that their venom can potentially be used to treat medical diseases in humans. Therein lies the possibility of one day treating human diseases with the help of snakes!

3. Ecotourism. People from countries abroad come to Trinidad and Tobago to see the many snakes we have here. Because of our proximity to South America, Trinidad and Tobago has a variety of snake species (over 40 at the moment). Some of these include the largest snake in the world: the green anaconda, the longest venomous snake in the western hemisphere: the bushmaster, and some of the rarest in the world: the Tobago false coral, an island endemic found nowhere else in the world!

Erythrolamprus ocellatus Tobago false coral, harmlessly resting on hand. Photo by Renoir Auguste

4. Harmless unless provoked. Believe it or not, the majority of snakes in the country are harmless, unless of course they are provoked. Like any wild animal (or human), no one likes being provoked. To snakes, people are threats to their lives, and if they are picked up or stepped on, their instinct will be to try and protect themselves. There are snakes that can potentially cause harm to people in Trinidad, for example the four venomous species: (1) mapepire balsain (aka fer-de-lance), (2) bushmaster, (3) large coral, (4) small coral. However, these snakes will not go out of their way or comfort zone to bite people unless they have been provoked. 

5. Snakes are animals and alive, just like you. Although some cultures have used snakes in their folklore stories to be mythical in nature, in reality, snakes are just animals that are part of the world we live in. Humans share a world with snakes and other wildlife, and should remember that without them, there can be dire consequences to people. 

To learn more about the snakes in Trinidad and Tobago, get your copy of the latest "Field Guide to the Amphibians and Reptiles of Trinidad and Tobago"!

You don't need to love snakes, but at least have appreciation for them. I assure you, they want to avoid you as much as possible too.

Invasion history and success for the introduced lizard 'Anolis wattsi' in Trinidad

Anolis wattsi (Watts Anole) from Arima, Trinidad. Photo by Adam Fifi

Anolis wattsi or Watt's Anole is native to Antigua and is one of a few Anolis species introduced to Trinidad. Anolis wattsi is smaller, prefers lower perches and has a higher field body temperature when compared to other Anoles (Michaelidis et al. 2019). These factors have contributed in some way to its successful establishment in Trinidad and a recent report further backs this with its apparent spread across the island (Fifi and Auguste 2017).

Anolis wattsi was first discovered in Trinidad in 1992 by Graham White, current editor of Living World, Journal of the Trinidad and Tobago Field Naturalists' Club. The lizard was first spotted on pineapple plants which suggested a possible source as to how it got here. However, later surveys found no evidence to back this up. Thus, the actual introduction source was unresolved. Michaelidis and colleagues (2019) then used genetic studies to infer the source of introduced Anolis wattsi populations in Trinidad.

Based on their genetic results, Anolis wattsi populations in Trinidad more likely came from the northern part of Antigua, as opposed to the south where pineapple plants are cultivated. Also, the spread of individuals within Trinidad is likely from individuals already in the island.

Although competition among Anolis lizards is great when similar ecomorphologically, the only species (currently) that Anolis wattsi closely cohabitates with in Trinidad is Anolis aeneus. This species is larger, uses higher perches, and thus to an extent avoids competition (for resources like microhabitat and food). Because of this, Anolis wattsi is likely to continue to establish itself further in Trinidad.

References:

Michaelidis et a. 2019. Genetic reconstruction of the invasion history of Anolis

wattsi in Trinidad with a comment on the importance of ecological

similarity to invasion success. Herpetological Journal 29: 131-139.

Fifi, A., and Auguste, R.J. 2017.  New localities for the introduced Anolis wattsi (Squamata: Dactyloidae) on Trinidad, West Indies.  Living World, Journal of the Trinidad and Tobago Field Naturalists’ Club, 2017: 51.

A frog in Trinidad glows in the dark

Polka-dot treefrog (Boana punctata) as seen under flashlight (left) and under UV light (right), Trinidad.
Photos by Renoir Auguste (left) and Rainer Deo (right).

In nature, when one thinks of animals that glow in the dark, perhaps fire flies (that are actually beetles) comes to mind first, or perhaps marine-minded people imagine those bizarre creatures in the depths of the ocean. Yet, not many people would start to think of frogs glowing in the dark, and it just so turns out, there are frogs that do it, and one such species can be found in Trinidad.

The polka-dot treefrog (Boana punctata) is perhaps one of the most colourful frogs on Trinidad. This widespread Neotropical frog gets its common name from the red dots on the back of individuals. A few years ago, researchers in Colombia, where the species also occurs, happen to shine a UV light in the forest at night, presumably looking for other wildlife. To their surprise, one animal they saw glowing under the light spectrum was a polka-dot tree frog. It appears this feature is not restricted to individuals in Colombia, as we have seen it as well in Trinidad.

Scientists currently do not know what is the purpose of this irridescent glow, which can also be seen in scorpions. Presumably, it perhaps plays a role in visual communication among conspecifics (individuals of the same species). It is something that is noteworthy of investigating further. Who knows what other animals we might find glowing in the dark in our tropical forests, and what it may mean for all biodiversity.

To learn more about this amazing frog that glows in the dark in Trinidad, get your copy of the field guide to the amphibians and reptiles of Trinidad and Tobago. Details at link here.

Protected Areas and Trinidad and Tobago's Herpetofauna

Tobago Glass Frog. Photo by Renoir Auguste

Protected areas represent a management tool (or strategy) to help conserve biodiversity. Biodiversity is not only important to wildlife conservation, but to human health, local communities and national economy as well. In order to maximize the effectiveness of protected areas and its overarching uses, information on the species present within them is fundamental. Species lists represent a component that all designated protected areas should have in order to properly manage them and those in and around it. Monitoring has shown to improve management plans with updated information.

Trinidad and Tobago has a variety of designated protected areas. Yet, species lists for them are lacking. A national ecological baseline study (Project ID: GCP/TRI/003/GFF) aimed to help fill this gap for six pilot protected areas. The six areas that were under consideration for protected status (or in some cases, improved protected status) included the Caroni Swamp, Nariva Swamp, Matura National Park/Matura Forest, Trinity Hills, Main Ridge Forest Reserve, and North East Tobago Marine Protected Area. Many different taxonomic groups were assessed, including the amphibians and reptiles (herpetofauna).

Main Ridge Forest Reserve. Photo by Renoir Auguste

From the baseline survey results, 67 herpetofauna species were recorded within the six pilot protected areas. These included 25 amphibian species, 4 turtle species, 1 crocodilian species and 37 squamate (lizard and snake) species. These represent about 70% of the country's amphibians and 50% of the reptiles currently known for the country, suggesting these protected areas are important areas for herpetofauna.


Improved management of the protected areas, national policies, and future monitoring can be based on these results. Indeed, the local government has recently accepted a National Protected Areas System Plan to protect areas in Trinidad and Tobago to help conserve biodiversity based on these results. Hopefully with funding and support, longer term monitoring and local community outreach activities can help provide more quantitative data needed to maintain the long term sustainability of these protected areas and the conservation of biodiversity within them for the benefit of all.

Reference:

Auguste, R.J. (2019). Herpetofaunal checklist for six pilot protected areas in Trinidad andTobago. Herpetology Notes 12, 577-585.

Frogs and habitat quality and why it matters

Urich's frog - Pristimantis urichi (foreground) and Cane toad - Rhinella marina (background). Photo by Rainer Deo

Cane toads (Rhinella marina) are considered habitat generalists whereas Urich's frog, (Pristimantis urichi endemic to Trinidad and Tobago) are habitat specialists - found in forests and at forest edge. The Urich's frog can potentially be used to assess habitat quality with its presence whereas Cane toads can sometimes indicate a relatively disturbed habitat. However, due to the ubiquitous habits of the cane toad, sometimes their paths do cross with forest specialist species. One example can be seen here (photo above) where both species were observed at the Arima Valley in Trinidad, near the William Beebe Research Station (aka Simla).

However, with increasing development, the likelihood of more sightings like these will be limited. As more forest is lost to human disturbance, more forest specialist species will be lost. Frogs have been noted to act as indicators of environmental health, and, also provide health benefits to people such as potentially treating diseases (example diabetes). Not everyone likes frogs, but at the very least, everyone should put effort to protecting them, if not for the benefit of other animals and the environment, but to people health and well-being.

To learn more about these frog species and other local species in Trinidad and Tobago, get your very own copy of the Field Guide to the Amphibians and Reptiles of Trinidad and Tobago! See more info here.

One of Trinidad's geckos gets a name upgrade

Gonatodes ferrugineus (formerly G. humeralis) from Trinidad. Photo by Renoir Auguste

Geckos are a group of terrestrial vertebrates that tend to be restricted to small geographic ranges. The exception appears in the genus Gonatodes. One species in particular has a range of over a million square kilometres - Gonatodes humeralis commonly called the spot-nosed gecko. However, given its small size, the likelihood of one single small species spread so far is questionable.

Pinto and colleagues (2019) looked into this and used molecular genetic data to investigate the population genetic structure and species delimitation of this Neotropical dwarf gecko. Based on their findings, there is species-level divergence evidence of the population on Trinidad, compared to South America. As such, Gonatodes ferrugineus was resurrected from synonymy for this population.

This is another example of where further research uncovers findings that are there to be discovered.  These findings provide another update to be edited for the future second edition of the field guide to the amphibians and reptiles of Trinidad and Tobago.

Reference
Pinto et al. 2019. Population genetic structure and species delimitation of a widespread Neotropical dwarf gecko. Molecular Phylogenetics and Evolution. 133: 54-66.
https://doi.org/10.1016/j.ympev.2018.12.029

New snake, now a new lizard for Tobago

Tobago appears to have an amazing array of unique animals, when compared to Trinidad. Both islands have species unique to each island. Yet, it appears Tobago has more unique wildlife. The herpetofauna are no exception.

Newly described lizard to Tobago: Bachia whitei. Photo by John C. Murphy

In January 2019, a paper came out describing a new snake species for Tobago.

Now, Tobago also has a new lizard species.

Lizards in the genus Bachia at first glance look like worms or small snakes from afar. However, upon closer inspection, the small limbs can be seen.

Most people probably have never seen a Bachia lizard. This may be due to them mainly living under leaf litter or in the surface of soil. They feed on small invertebrates in the soil, such as termites.

Trinidad and Tobago have at least two species of Bachia. One is astutely named Bachia trinitatis which is found in Trinidad and Tobago. However, Tobago has the second species: Bachia whitei (currently considered an island endemic - found no where else in the world!)

Bachia whitei was named in honour of Graham White - current chairman of the Asa Wright Nature Centre's board, and Editor in chief of the Living World Journal of the Trinidad and Tobago Field Naturalists' Club.

Perhaps the easiest way to distinguish between the two species is the shape of the scales on the body. Bachia trinitatis has hex scale patterns, whereas Bachia whitei has square scaled patterns.

To learn more about these lizards, check out the "Field guide to the amphibians and reptiles of Trinidad and Tobago" which can be bought online if living outside of the country (info here). For those living in Trinidad and Tobago, contact the TTFNC on where you can get a copy.

Poaching of sea turtles in Tobago: Culture, Consumption and Conservation

Hawksbill sea turtle at Castara, Tobago. Photo by Mike Rutherford.

Background
There are five sea turtle species recorded for Trinidad and Tobago: Leatherback (Dermochelys coriacea), Hawksbill (Eretmochelys imbricata), Green (Chelonia mydas), Loggerhead (Caretta caretta) and Olive Ridley (Lepidochelys olivacea) [Murphy et al. 2018]. All five are designated Environmentally Sensitive Species (ESS) in T&T. Sea turtles face various threats. Some of these include climate change, loss of habitat, pollution (including from artificial light) and poaching/exploitation (Hailey and Cazabon-Mannette 2011). Poaching of sea turtles occurs in Trinidad and Tobago despite the year long legal protection of these ESS.

Aim
In 2018 as part of a Conservation Leadership in the Caribbean programme, I embarked on a venture to acquire current information on the status of poaching of sea turtles in Tobago, Trinidad and Tobago, specifically to understand the culture and perception as to why it persists for hopes of improving future conservation management plans for the species to be used by relevant stakeholders.

Method
I spoke with some of the main stakeholders involved in turtle conservation on the island (n=8), including government officials, and non-governmental officials, which included those from turtle patrol groups, and community conservation personnel (where turtle patrol groups were absent from known nesting villages). The objectives were to gain a better understanding of the demand for consuming sea turtles and their eggs.

Results
Poaching is regarded as the main threat to sea turtles on the island, particularly in the north, whereas habitat loss/alteration is regarded as a major threat to sea turtles in the south of the island. This may be unsurprising as the south of the island is more developed and development is continuing to meet the needs of tourism, whereas the north of the island may be considered more rural.

Speaking about the particular species of sea turtles, the hawksbill is perhaps the most exploited of the sea turtles on Tobago. Reason being that it is a preferential choice by the locals to consume the meat of hard shell species compared to the leatherback.  The hawksbill is also a more frequent nesting species in the north of Tobago than the leatherback, whereas the other hard shell species such as the green (nesting females) is less common. The hawksbill is currently regarded as Critically Endangered.

Contributing factors and Challenges:
-turtle meat is viewed as a cultural status (turtle meat is more highly regarded than perhaps chicken or fish);
-food source (one local referred to turtle meat as "sea goat" and says people like how it tastes and it would be difficult to stop eating it);
-lack of financial alternatives (which is an issue among many rural communities);
-lack of financial support for turtle conservation (there are, but perhaps more is needed);
-Lack of enforcement and support from local government (most game wardens only work from 8 am to 5 pm, but sea turtles nest predominantly at night);
-limited legislation (lack of prohibited turtle nesting beaches on Tobago, unlike on Trinidad);
-remoteness of nesting beaches on Tobago (access to monitor and patrol all nesting beaches is already made difficult by lack of resources and finances, but the inability to easily access some beaches is also a problem);
-increased craftiness of poachers (for example, knowing how to avoid persons on patrols and using the latest technology);
-some people that are on beaches monitoring turtles may also be poachers or colleagues of poachers (but with limited persons willing to help out, how does one vet such a situation?);
-lack of awareness/knowledge gap (one official claimed that sea turtles should be eaten to keep their populations in check - although did acknowledge that more data are needed to validate this).


Management measures needed:
-more educational awareness programmes to highlight the importance of sea turtles (and how they help people and boost the economy);
-greater support from the local government;
-patrols on beaches where turtles are known to nest but currently has no monitoring in place (perhaps implement a community plan for those from the community to monitor these beaches?);
-greater financial support, which, is needed to help with all management measures (there can be incentives for conserving these species, which in the long term can not only be beneficial to the turtles, but for ecotourism and the economy of the country);
-designating prohibited areas for high density turtle nesting areas (although perhaps it may seem this may clash with tourism, on the contrary, considering how much money comes in just from people paying to watch sea turtles on Trinidad, this is something that can be followed up on Tobago).

Conclusion
More work is needed. It will require a collaborative effort but most importantly, from people at the local communities. They stand to benefit from having these sea turtles around as do all. This has been reported by Cazabon-Mannette and colleagues (2017) who found that there are significant non-use and non-consumptive values of sea turtles in Tobago, and this highlights the importance of sea turtle conservation efforts in Tobago.  If the the turtles are gone, not only will the marine ecosystem and all the other species (including fish) diminish, but also the local economy.

Leatherback laying eggs. Photo by Renoir Auguste.

References

Cazabon-Mannette, M., Schumann, P.W., Hailey, A., and Horrocks, J. 2017. Estimates of the non-market value of sea turtles in Tobago using stated preference techniques. Journal of environmental management 192: 281-291.

Hailey, A., and Cazabon-Mannette, M. 2011. Conservation of herpetofauna in the Republic of Trinidad and Tobago. Pp 183-217 in Hailey, A., Wilson, B.S., and Horrocks, J.A. (Eds.), Conservation of Caribbean Island Herpetofaunas, Volume 1, Conservation Biology and the Wider Caribbean. Leiden: Brill.

Murphy, J.C., Downie, J.R., Smith, J.M., Livingstone, S.R., Mohammed, R.S., Auguste, R.J., Lehtinen, R.M., Eyre, M., Sewlal, J.N., Noriega, N., Casper, G.S., Anton, T., Thomas, R.A., Rutherford, M.G., Braswell, A.L., and Jowers, M.J. 2018. A field guide to the amphibians and reptiles of Trinidad and Tobago.  Trinidad and Tobago Field Naturalists’ Club. 336 pp

Tadpole cannibalism in Trinidad

Trinidad stream frog (Mannophryne trinitatis) feeding on its conspecific. Photo by Renoir Auguste

The idea of cannibalism brings thoughts of horror movies. Yet, in the animal kingdom it occurs more frequently than we think. Cannibalism appears to offer benefits to animals. Some of these include sources of food in resource poor environments, and reduced development time. However, there are also disadvantages of cannibalism, for example increased risk of disease.

Cannibalism has been recorded in a variety of animals, including frogs. One such frog whereby cannibalism has been observed is the Trinidad stream frog (Mannophryne trinitatis); an island endemic. As the common name suggests, it is found across streams in Trinidad, abundantly across the Northern Range, but also in the Central Range. When mating occurs, the males take the tadpoles on their back and carry them to pools of water, often void of predators for them to develop. Sometimes these pools of water are large. Other times, the pools of water are small, leaving them prone to drying up, especially in the dry season. When this happens, competition for resources among the tadpoles in the pool increases.

An example of potential cannibalism was seen in 2018 (Auguste and Angeli 2018). The tadpoles were observed in a relatively small pool of water with the nearby stream dried up. It was unclear if the tadpole had already died and its conspecifics were feeding on it - or if they attacked it while it was still alive. Nonetheless, why does cannibalism persist with this species? Perhaps with further study one can discern what the contributing factors are. This may then provide insight into adaptations to the quality of habitat and to changing climatic conditions.

Reference

·        Auguste, R.J. and Angeli, N.F. 2018. Field observations of potential cannibalism among tadpoles of the Trinidad stream frog Mannophryne trinitatis (Anura: Aromobatidae). Living World, Journal of the Trinidad and Tobago Field Naturalists’ Club, 2018: 104-105.

Frogs being eaten by spiders

Spider (Ancylometes bogotensis) with its captured frog (Leptodactylus validus) in Trinidad. Photo by Renoir Auguste.

Spiders appear to feed on almost any animal that they can overpower. Although their main prey consists of insects and other invertebrates, they also feed on vertebrates such as mammals and frogs.
Spiders prey on a variety of species of frogs from across the Neotropics, and Trinidad is no exception. These types of predator-prey relationships are rarely encountered in the wild by people. However, when they are observed, it helps add to our knowledge of the natural history and ecology of these animals.

Tracking Trinidad's Treefrogs

Leaf nesting frog (Phyllomedusa trinitatis) from Trinidad. Photo by Renoir Auguste

One of the fundamental aspects of assessing the ecology of an animal, is to track its movement. Often, this is difficult as animals cannot be observed continuously. One way to off set this disadvantage, is with the use of tracking devices. However, tracking methods can have both advantages and disadvantages.

The leaf nesting frog (Phyllomedusa trinitatis) is a frog found in Trinidad and Venezuela (Murphy et al. 2018). An evaluation study on tracking the movement of this species was undertaken at Simla, in the Arima Valley in Trinidad (Gourevitch and Downie 2018). Tracking devices consisted of (1) harness made of cotton with bobbins, and (2) radio-tags. Observations on the frogs were conducted in lab and in the field.

Twenty-six frogs were assessed, with 16 of these successfully tracked. Both methods presented challenges. However, the locations of where the 16 frogs (1 female and 15 males) rest during the day were revealed and gives greater insight to the habitat use of these frogs. Further, the female that was tracked appeared to move further away from the breeding pool than the males. Though both tracking methods appear to not work perfectly for Phyllomedusa trinitatis, the study emphasizes the need to test out tracking methods on different species in their respective habitats.


Citations:

Gourevitch, E.H.Z., and Downie, .J.R. 2018. An evaluation of of tree frog tracking methods using Phyllomedusa trinitatis (Anura: Phyllomedusidae). Phyllomedusa: Journal of Herpetology 17: 233-246.

Murphy, J.C., Downie, J.R., Smith, J.M., Livingstone, S.R., Mohammed, R.S., Auguste, R.J., Lehtinen, R.M., Eyre, M., Sewlal, J.N., Noriega, N., Casper, G.S., Anton, T., Thomas, R.A., Rutherford, M.G., Braswell, A.L., and Jowers, M.J. 2018. A field guide to the amphibians and reptiles of Trinidad and Tobago.  Trinidad and Tobago Field Naturalists’ Club. 336 pp.

The elusive and important freshwater turtles of Trinidad

One of three native freshwater turtles on Trinidad: Gibba turtle (Mesoclemmys gibba) Photo by Renoir Auguste.

Trinidad and Tobago are well known for the nesting marine turtles along the coasts. There have been numerous conservation efforts to highlight their importance thanks to local community groups, and international bodies. Typically, when a local person thinks of 'turtle' the Leatherback (Dermochelys coriacea) might usually come to mind more often than any other. However, Trinidad has three native freshwater species of turtles. Surprisingly, not many people are aware of these three turtles’ existence on Trinidad. 

The first of the three native species is perhaps currently the most commonly encountered: The Galap or painted wood turtle (Rhinoclemmys punctularia) from the family Geomyididae. This family is the most species rich family of turtles globally with about 75 species recorded. They are represented with species across Europe, Asia, Africa and Central and South America. The Galap is the sole species from the family here. Individuals grow to an average size of about 20 cm. They can be identified by having red blotches on the crown of their head, yellow reticulations near the ear, and yellow or red spotted scales on the forelimbs. The Galap appears to be mainly found in south Trinidad with populations north centrally as well. Their habitat mainly consists of ponds or streams in forests, and can also be found at road side ditches. They are omnivores, and are known to act as seed disperses as they feed on fruits thus contributing to plant growth which benefits plants, other animals, and humans. 

Galap (Rhinoclemmys punctularia) feeding on fruit in south Trinidad. Photo by Renoir Auguste

The second of the three native freshwater turtles is the scorpion mud turtle (Kinosternon scorpioides) from the family Kinosternidae. This family has 25 species and are restricted to the western hemisphere. The scorpion mud turtle is the sole species on Trinidad currently, although subfossil remains hints at another species once being here. They grow to about 27 cm. The turtle can be identified by their domed carapace (shell) which varies from light brown to olive, with a brown-yellow head. They appear to be distributed across the south and northern basins of Trinidad; similar to the Galap. They may be found in temporary or permanent freshwater habitats, roadside ditches, and stream impoundments surrounded by forests. Although it may be relatively common, they are not always commonly seen and this may be because they bury themselves in the bottom of the pond or stream where they reside when it dries up, or are almost always under water when wet. Like the other two species they are nocturnal but may be active during the day. They are predominantly carnivores feeding on insects, molluscs, crustaceans, fish, frogs, worms, and mammals, but will consume algae and plant matter, including fruits thus also making them potential seed disperses.

Scorpion mud turtle (Kinosternon scorpioides) from central Trinidad. Photo by Rainer Deo

The third native freshwater turtle species is perhaps the rarest on the island and rarely encountered: the Gibba turtle or side neck turtle (Mesoclemmys gibba) from the family Chelidae. There are about 53 species restricted to Central and South America. They are able to move their necks sideways into the shell (hence the common name). All are highly aquatic with the capacity to stay submerged for long periods of time. The Gibba turtle grows to about 30 cm. They can be identified by having a wide and flattened head with two barbles on the chin, dark brown or black carapace or shell and extensive webbing in the feet. Very little is known about this species locally. Previous literature suggests it is an uncommon lowland species. A survey published in 2010 found that they were restricted to the South Oropouche catchment based on anecdotal evidence from locals. However, as of 2018, individuals have been spotted by myself not far from the Aripo Savannas Scientific Reserve which is designated an Environmentally Sensitive Area in Trinidad. Like the other two species, they prefer areas with stagnant waters in forests, however with closed canopy. This suggests they would be susceptible and sensitive to habitat alteration. They are also nocturnal and are omnivores: also feeding on fruits like the other two species.

Gibba turtle (Mesoclemmys gibba) from northern Trinidad. Photo by Renoir Auguste

Given the high precedent to marine turtle conservation, these three freshwater turtles should also be considered for priority conservation in Trinidad. They are an important component of the local fauna and ecosystems because of their seed dispersing capabilities and varied diet. They also comprise an important component of freshwater ecosystems. Greater effort towards learning more about their ecology is needed, which would not only benefit the local population of turtles but the freshwater ecosystems where they reside, other wildlife, and people.

Murphy, J.C., Downie, J.R., Smith, J.M., Livingstone, S.R., Mohammed, R.S., Auguste, R.J., Lehtinen, R.M., Eyre, M., Sewlal, J.N., Noriega, N., Casper, G.S., Anton, T., Thomas, R.A., Rutherford, M.G., Braswell, A.L., and Jowers, M.J. 2018. A field guide to the amphibians and reptiles of Trinidad and Tobago.  Trinidad and Tobago Field Naturalists’ Club. 336 pp.

The frog Leptodactylus nesiotus is no longer endemic to Trinidad

Leptodactylus nesiotus from Trinidad. Photo by Renoir Auguste.

As of 2014, the island of Trinidad was known to have four species of endemic frogs: Trinidad stream frog Mannophryne trinitatis, Urich's litter frog Pristimantis urichi, Golden tree frog Phytotriades auratus and Trinidad thin-toed frog Leptodactylus nesiotus. 

In 2015, there were now three endemic species after the discovery of the Golden tree frog (Phytotriades auratus) in Venezuela (Rivas and de Freitas 2015). Now, at the end of 2018, the number of endemic frog species is down to two after Leptodactylus nesiotus were discovered in the Guianas (Guyana, Suriname and French Guiana), South America.

The Trinidad thin-toed frog (Leptodactylus nesiotus) is a member of the Leptodactylus melanotus group. They are known from swampy areas in south west Trinidad and also from the Nariva Swamp. Jairam and Fouquet (2018) reported on specimens occurring along coastal savannas and swamps on mainland South America, along the Guianas. Given the very wide distribution and continuity of habitat, the authors suggest that specimens of L. nesiotus may have been mistaken for L. validus or other species of the L. melanotus group. They also suggest that specimens are also likely to occur in Venezuela and may even occur in Colombia and Brazil. 

Little is known about the biology of the species from Trinidad and prior to its discovery in South America, it was given the IUCN Red List Status of Vulnerable. With an extension of greater than 1000 km, perhaps the status of Vulnerable now needs to be reassessed to Least Concern. 

It is unsurprising that L. nesiotus is not an island endemic to Trinidad, especially given its main population in south western Trinidad is less than 20 km from Venezuela. Also, in Trinidad, the species has been observed to live alongside L. validus. Perhaps further investigations of other endemics may reveal a much wider distribution, which further highlights the biogeographical link to the Trinidad and South America fauna.

Literature Cited

Rivas, G. and 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.

Jairam, R. and Fouquet, A. 2018. First records of Leptodactylus nesiotus (Anura: Leptodactylidae) for Guyana, Suriname and French Guiana. Herpetology Notes 11: 997-999.