Saturday, August 16, 2025

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.

Saturday, April 12, 2025

History of Amphibian Research in Trinidad & Tobago

[Tobago glass frog, Hyalinobatrachium orientale tobagoense. Photo by Renoir Auguste]. When most people think of amphibians (frogs) in Trinidad and Tobago, the crapaud or cane toad is typically the first that comes to mind. But did you know T&T has 35 species of amphibians? These frogs come in different sizes, shapes, and colours. They occur mostly in forests, but also in savannas, marshes, and even in our homes (usually the crapaud or Johnstone whistling frog). Most of what we know about the amphibians in the country can be traced to key figures over the last few decades. If you are interested in learning more about the history of amphibian research in T&T, then perhaps you may want to start with Julian Kenny's 1969 book on the Amphibia of Trinidad. One key line from his book is “Since Parker’s 1933 list was published, the names of nine of the twenty-three species have been altered in one way or another, some even at the generic level, while two unrecorded species have been found. Further, “surprisingly little recorded on general life histories of the Trinidad species or of mainland representatives of these species”. You may be wondering why I am pointing out that quote: more on that later. In Kenny's book, he first documented 25 species of amphibians (on Trinidad only). He provided data on distribution, habitat preferences, and identification keys for the frogs found on the island. In particular, not only did he devise keys to identifying adult frogs on Trinidad, but tadpoles too, which, can be challenging! These identification keys are mostly still used today, more than half a century ago.
Fast forward to the 1990s, and the other integral person to contribute to knowledge on T&T's amphibians is John Murphy. Murphy produced a landmark book, the first for the country documenting both the amphibians and the reptiles known from T&T. His book, based on more than 10 years of research provided information on the distribution of species (updated from Kenny's 1969 book), natural history (a gap that Kenny noted prior), and also new names to some of the species on the islands. Changes to species names sometimes happens when new scientific data arises, particularly DNA. Murphy has been studying T&T's herpetofauna for well over 40 years now, and without him, we would know so little about the underappreciated herps in the country.
We move forward to 2018, and Murphy, together with colleagues put together an updated version of his 1997 book, a field guide - one we can take with us in the field (a bit smaller than his 1997 book). This guide provides updated information on the distribution, natural history, and names to more species (though some names have changed since!). This field guide is still one of the most used references to amphibian research in the country.
Now, in 2023, a chapter was (finally) published in a Caribbean amphibian conservation book. The book features information on amphibians for all the Caribbean countries that have amphibians, including T&T. The chapter is authored by local and international researchers who have all contributed to herpetology in the country. Unlike the field guide, it is not readily available locally, but can be purchased online for interested persons. Here, we provide updated information on T&T's amphibians since the field guide came out. Some notable upates include the redescription of a new species of frog, an update on the conservation status of all the frogs in the country, and new natural history information.
Overall, amphibian conservation and research in Trinidad and Tobago has had a strong foundation, thanks to Kenny, Murphy, Downie, and others. It is in the best interest of all that we continue this and contribute to sustainable biodiversity management in the country - and not to leave out amphibians!