Conservation of three endemic Pristimantis frogs in Trinidad and Tobago

Pristimantis is one of the most species rich genus of animals on Earth. Trinidad and Tobago has three species of frogs in that genus. One is found in Trinidad and Tobago (Urich's litter frog Pristimantis urichi), the other two are found on Tobago only (Charlotteville litter frog P. charlottevillensis, and Turpin's litter frog P. turpinorum). A recent published study (link here) provided updated and novel information on the ecology, conservation status, and genetics of these frogs. Based on the conservation status, the frogs were previously listed as Vulnerable, Least Concern, and Vulnerable, respectively (for P. urichi, P. charlottevillensis, P. turpinorum). However, based on the ecological information such as distribution and relative abundance, these were amended to be Least Concern, Vulnerable, and Data Deficient, respectively. More genetic data are needed for populations in South America, but data in this study found that P. turpinorum is closely related to Venezuelan species, more so than P. urichi and P. charlottevillensis. Further biological information is needed, especially for P. turpinorum which was classified as Data Deficient. How threats such as climate change and land use change will affect these frogs remain larely unknown. Hopefully these gaps will be filled in the near future so as to protect these unique and endemic frogs which play an integral role in biodiversity. To learn more about one of these three frogs, see this local newspaper story feature (link here).

Pristimantis turpinorum pair observed in the Main Ridge Forest Reserve. Photo by Renoir Auguste.

Bloody Bay Litter Frog, Pristimantis turpinorum (Family Craugastoridae)

Turpin's Litter Frog, Pristimantis turpinorum, is endemic to the forests Tobago's Main Ridge. Adults are 15 to 19 mm in body length and the eye's diameter is about 1.25 times the eye-nostril distance. The iris of the eye does not contain any blue pigment. Males call from palm trees in the late afternoon and usually stop calling when it is dark. It is a poorly studied species and little is known about its natural history. Photograph at left Renoir J. Auguste.

Conservation Status of Trinidad & Tobago Frogs updated on IUCN 2020 v3

Tobago Glass Frog (Hyalinobatrachium orientale tobagoense). Photo by Renoir Auguste

 The International Union for the Conservation of Nature (IUCN) is a widely, credited source of species' conservation status across the world. Thousands of species have been assessed, many more (hundreds of) thousands are yet to. Trinidad and Tobago (currently) has 35 recognized species of amphibians, all Anurans or frogs and toads. All 35 species have been assessed on IUCN and their updated conservation status came out in the 2020 version 3 update. Local and international experts were consulted to provide information to assess each species.

From the new update, 30/35 (85%) species are listed as Least Concern, or not currently threatened with immediate extinction. One species is listed as Endangered, three as Vulnerable, and one Data Deficient. 

The Endangered species is the golden tree frog (Phytotriades auratus). This species was previously listed as a Trinidad endemic frog and Critically Endangered, but the IUCN Amphibian SSC Group believes that its discovery in Venezuela warrants a lower threat level because of its wider distribution, despite its very restricted microhabitat.

The three Vulnerable species are all Tobago endemics: The Tobago stream frog (Mannophryne olmonae), Charlotteville litter frog (Pristimantis charlottevillensis), and Tobago glass frog (featured in photo above). The Vulnerable threat level was assigned given their restricted area of occupancy.

The one frog listed as Data Deficient, is the Tobago endemic Turpin's litter frog (Pristimantis turpinorum). Since its formal description in 2001, very little information is known about its biology, likely because of its very secretive habits, with too few specimens observed. This species is a prime example where research is needed to help provide much needed information about updating its conservation status, and prohibiting its potential extinction. 

Turpin's litter frog (Pristimantis turpinorum). Photo by Renoir Auguste

More work needs to be done, but at least provisional efforts have contributed to us knowing more about these important animals, some of which can be found nowhere else in the world.

Links to some of the species' IUCN status:

https://www.iucnredlist.org/

Herping in Trinidad & Tobago Part 2: Main Ridge Reserve (Amphibians)

The Main Ridge Forest Reserve is one of the oldest desginated forest reserves in the world. It is found on the island of Tobago, Republic of Trinidad and Tobago. Here, multiple unique amphibians and reptiles can be found - some of which exist nowhere else in the world! Among the unique amphibians that can be found here include a handful of endemic frogs. If you are walking along a trail in the Reserve during the day, you would most likely hear the Tobago stream frog calling. However, at night, more frogs are active and can potentially be detected (especially during the rainy season). These include three species of leaf litter frogs in the genus Pristimantis = (charlottevillensis, turpinorum, urichi). The first two are only found in Tobago, while the latter only occurs on Trinidad & Tobago.

Pristimantis charlottevillensis, Charlotteville litter frog can be easily seen in the Main Ridge. Among the three Prisitmantis species, this one is the largest and can often be seen on the ground. A distinct feature if the golden colour of their eyes.

Pristimantis turpinorum, Turpin's litter frog is perhaps one of the hardest frogs to see if herping in the Main Ridge. The species is currently classified as 'data deficient', meaning we know very little aout the frog. This is worrying as the frog is also only found in Tobago, yet could be threatened! More information is needed so that we can better protect the frog for generations to come.

Pristimantis urichi, Urich's litter frog is widespread across the Main Ridge. These frogs have a light blue colour in the upper part of the eyes - a distinct feature of this species. They are usually very well hidden in vegetation as they call about a metre off the ground. But if you look closely and follow the sound of their peep call, you may spot one!

Perhaps though, the most charismatic frog on the island is the Tobago glass frog (Hyalinobatrachium orientale tobagoense). These frogs have transparent skin on the belly, meaning you can see their organs, even their heart beating! These small, green frogs can be found near streams. The males are the one that guard the eggs, so most often you might spot a male calling on a leaf over hanging water. For more information on these frogs, check out "The field guide to the amphibians and reptiles of Trinidad and Tobago"! Available here. || Stay tuned for the follow up post highlghting some of the unique reptiles (lizards and snakes) that can be found in the Main Ridge Forest Reserve in Tobago! All photos by Renoir Auguste.

Why we need to save and better protect amphibians

(Photo: Turpin's frog, Pristimantis turpinorum, mating pair, observed in Tobago. Photograph by Renoir J. Auguste). | A recent study published in the journal Nature has highlighted Ongoing declines for the world's amphibians in the face of emerging threats (link to open access paper here). It highlights 41% of the world's amphibians are threatened with extinction. "Amphibians are the vertebrate class more threatened than any other (more than mammals, birds, reptiles). Among the global threats impacting amphibians, climate change has emerged as one of the primary drivers of declines within the last two decades (2004 - 2022). The greatest concentrations of threatened amphibian species have been found to occur in (but not limited to) the Neotropics, including the Caribbean islands". From my general reading of the literature, amphibian species on islands can potentially be more vulnerable to global threats like climate change because of smaller ranges and specific microhabitat requirements. As noted in the study published in Nature, "scaled-up investment is urgently needed to help reduce current trends. In particular, increased political will and sufficient resource commitments are necessary for the conservation of amphibians". Unfortunately, from my point of view, there appears to be little resources geared towards amphibian conservation in some places, especially where they are needed the most such as in the Caribbean. This is a call to attention to all stakeholders (government, policy implementers, private companies, local community persons, ecotourists, NGOs) to commit to saving your local/native amphibians. Why? Amphibians are important to both the natural ecosystem, and to humans. Amphibians feed on a variety of insects, including ones we call pests, and are food to other animals. Amphibians are also of medical importance to people, based on research being carried out on the biochemisty of their skin. Important work and resoruces have gone towards tackling climate change issues towards human developed areas (example flooding), and on other vulnerable/important animals like bees, and hunted game mammals. However, this report clearly identifies that amphibian conservation efforts need improving. The time to act is now. Let's all work together towards protecting these amazing animals, because if the world lost all its frogs, there would be no world left for us humans.

Photos needed for the next Trinidad & Tobago Field Guide

We are making progress on the Trinidad and Tobago Field Guide and the goal to to have it ready for copy editing by the end of 2014. The extended dry season of 2014 has made it difficult to find animals and we still are looking for photos of  species we don't have represented. While it is improbable we will find live specimens of species known from a single specimen or just a few specimens we are looking for the best photography we can find. We are also looking for the best photography of Trinidad and Tobago specimens - that is we would rather have photos of specimens from the islands than from the mainland or other islands if at all possible.

So the following is a list of species we still need, or we need better photos than the ones we have. If you have photos that you are willing to let us use - send me (JCM) an email at: serpentresearch@gmail.com

Leptodactylus nesiotus, Pristimantis turpinorum, Mesoclemmys gibba, Anolis extremus, Anolis trinitatis, Anolis wattsi, Kentropyx striata, Drymarchon corais, Leptophis stimsoni,, Tantilla melanocephala Erythrolamprus cobella, Erythrolamprus ocellatus, Hydrops triangularis, Thamnodynastes ramonriveroi, Micrurus circinalis, Micrurus lemniscatus diutius, Lachesis muta. 

If you have great photos of other species we are interested.