Sunday, January 2, 2022

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.

Thursday, November 4, 2021

Rediscovery of an elusive snake in Tobago

Snakes are often elusive animals. One can be walking along a forest trail and there could be one hiding in plain sight. The elusiveness of snakes, though, has resulted in some species not being observed for many years, sometimes even for decades. Observing elusive snakes in nature, can thus be rewarding and beneficial, not only for snake enthusiasts, but for the conservation of the species and biodiversity. An example of a snake that was recently rediscovered on the island of Tobago after going many years without being observed is the Hallowell's ground snake (Atractus fuliginosus). This small harmless snake (up to 30cm long) is a forest dwelling snake that lives in leaf litter. They feed on small soil invertebrates, making them important components of ecological food webs. A recent publication (reference below) documents updated records of this elusive snake on the island of Tobago (West Indies) over the past 7 years where records prior were scarce for more than a decade. Natural history notes on the species were documented based on these rare observations, and bioloigsts now know more about the snake. Perhaps this elusive snake is more common than we realise. Or worse, perhaps it is in danger of becoming extinct.
Hallowell's ground snake, Atractus fuliginosus. Photo by Renoir Auguste. || Reference: Murphy, J.C., Braswell, A.L., Weems, J., Auguste, R.J., Rivas, G.A., Rutherford, M.G., Schargel, W.E., and Jowers, M.J. 2021. The Rediscovery of Hallowell’s Ground Snake, Atractus fuliginosus, on Tobago with Notes on its Natural History. Herpetological Review 52(3): 488-492.

Wednesday, September 22, 2021

The importance of surveying Herpetofauna in EIAs

Painted wood turtle aka Galap (Rhinoclemmys punctularia). Photo by Renoir Auguste. An Environmental Impact Assessment (EIA) is an important tool used to help mitigate threats to biodiversity during anthropogenic development. Ecological surveys of fauna and flora are a core component of EIAs to gauge potential threats to wildlife in a proposed development area. Among fauna surveyed, the majority of assessments historically surved have been done on birds (for terrestrial areas) and freshwater and marine benthic organisms (for aquatic areas). Birds are relatively easy to survey. They often fly within sight, and also have distinct calls for the more secretive species. However, herpetofauna (amphibians and reptiles) should be given more consdieration for all EIAs moving forward. Amphibians are among the most threatened animals globally. They are sensitive to both terrestrial and aquatic pollution, and are especially susceptible to habitat loss. Amphibians would make ideal organisms to assess the biodiversity of a particular area. In addition to their sensitivity to habitat alteration, they make up important components of ecosystems, acting as predator and prey to a variety of other animals, and also can provide health benefits to people through research on their medically important compounds and diet comprising disease carrying mosquitoes. Amphibians can be secretive in habitats where they occur, but like birds, they also have species specific calls that can be used to identify and more easily record their presence. Trained herpetologists who can identify frog calls can thereofore be useed to help survey amphibians in an area. Reptiles also comprise important animals in ecosystems. They are mostly predators but also prey to many other animals. However, unlike amphibians, they do not make species specific calls (except some geckos), so tend to be more challenging to survey quantitatively. Reptiles (e.g. lizards), though, do tend to sometimes exhibit site fidelity, which means they like sticking around a particular area. This could then be used to assess where they like to live, and environmental conditions they prefer. This information can better inform EIAs. There are a lack of trained herpetologists that can identify frog calls and identify certain elusive reptiles in the country. If you are an EIA reviewer, developer, or consultant, we urge you to consider having herpetofauna as species to be surveyed in EIAs. Surveying for one taxa but not other major ones leaves an important gap in how biodviersity could be impacted by development. It is our responsibility to ensure all wildlife are managed sustainably. For more information on this post, do not hesitate to contact the author.

Tuesday, July 13, 2021

Conservation status of the Dwarf Marsupial Frog in Trinidad, Tobago, & Venezuela

 

Drawf marsupial frog (Flectonotus fitzgeraldi) female with eggs on back. Photo by Renoir Auguste

The dwarf marsupial frog is a small frog found in Trinidad, Tobago and Venezuela. It is a forest specialist species usually found in vegetation with closed canopy and near streams. They are called Marsupial frogs because the females carry their eggs in a pouch on their back, like the marsupials from Australia (that have the pouch by their belly). 

The International Union for the Conservation of Nature (IUCN) in 2004 regarded the dwarf marsupial frog as endangered. That status remained unchanged for 16 years. However, a team of researchers from Trinidad, Venezuela, UK, EU, & US compiled biological data done on the species in its respective range which provided important information for its conservation. Based on the surveys, the frog was found to be widely distributed across Trinidad, northeast Tobago and northeastern Venezuela. As such, the group, lead by professor Roger Downie from Glasgow University suggested that the conservation status be downgraded from Endangered to Least Concern. 

This is an important milestone for this species based on the updated information provided by this study. However, further studies on number of individuals in its range are needed to continuously monitor the species, as it can potentially revert to its more threatened status because of climate change, habitat alteration and diseases because of its very specific habitat requirements.

Reference

Smith, J., Jowers, M.J., Auguste, R.J., Hoskisson, P., Beyts, C., Muir, G., Greener, M.S., Thornham, D., Byrne, I., Lehtinen, R., Eyre, M., Rutherford, M.G., Murphy, J.C.,  De Freitas, M., Rivas G.A., and Downie, J.R. 2021. The distribution and conservation status of the dwarf marsupial frog (Flectonotus fitzgeraldi) in Trinidad, Tobago and Venezuela. Amphibian and Reptile Conservation 15(1): 36-56.

Link to paper here: http://amphibian-reptile-conservation.org/pdfs/Volume/Vol_15_no_1/ARC_15_1_[General_Section]_36-56_e273.pdf

Wednesday, June 23, 2021

Rutherford's Vine Snake From Trinidad Specializes In Eating Lizards

Photo of Rutherford's Vine Snake (Oxybelis rutherfordi) predating on a Beachrunner lizard (Cnemidophorus lemniscatus). Photo by Marie-Elise Maingot. Rutherford's Vine Snake (Oxybelis rutherfordi) or as locals refer to them "Horsewhip", was a recently (re)described species of snake found in Trinidad and Tobago and northern South America. Populations found here were previously thought to be the same as the widespread Brown Vine Snake (Oxybelis aeneus), but research showed they are two distinct species. In Trinidad and Tobago, Rutherford's Vine Snake is widespread, found in forests, coastlines, and even in residential gardens. Data on the diet of this species, and snakes in general are poorly known. Filling this gap is important as it allows us to learn more about how these animals use their environment and interact with it. A newly published Natural History Note was published in the journal "Phyllomedusa" and it documents five lizard species that Rutherford's Vine Snake feeds on. Observations were documented by keen citizen scientists from across Trinidad that luckily were able to photograph the snake predating on a lizard. These observations can be very rare to observe and thus highlighting them adds to biological data. To read more about the five lizard species that the Rutherford's Vine Snake feeds on, see this link to a pdf describing the events that took place here in Trinidad. If you are a passionate photographer, or generally enjoy nature, do not hesitate to share your photos of reptiles and amphibians with us! You can reach out to us on Instagram on the page "Herp.Research.TT", or email the Trinidad and Tobago Field Naturalists' Club asking for the Herpetology Group Leader.

Saturday, May 8, 2021

Boa constrictor feeds on a variety of prey, including doves

Boa constrictor predating on a Ruddy ground dove. Photos provided by Adam Fifi. || The Boa constrictor, locally known as Macajuel or red-tailed boa, is a common snake found across both Trinidad and Tobago (Murphy et al. 2018). This large, non-venomous snake is a top predator in ecosystems where they reside and help maintain food web balance. Boa constrictors feed on a variety of other animals, including small mammals such as rodent pests, lizards, and sometimes birds. Indeed, although Boa constrictors may be found mostly on the ground, they do sometimes climb up trees, which enables them the ability to prey on birds. An example can be seen in the Field Guide to the Amphibians and Reptiles of Trinidad and Tobago where an individual was observed predating on a crested oropendola, photographed by Edward Barrow. A Living World article by Hayes and Gabriel (2019) also highlights another common bird (kiskadee) that the Boa constrictor feeds on. However, an additional bird prey includes the very widespread and common Ruddy ground dove. This is perhaps the most easily seen and common bird in urban gardens, near residential areas. Thus, it may not be too surprising that the Boa constrictor also feeds on them. This natural history observation is the first reported documentation of this particular prey species, and was published in the international journal Herpetological Review in March 2021. This event took place on Gasparee island, and no doubt Boa constrictors continue to predate on other small animals there, and across Trinidad and Tobago. || References Murphy, J.C., Downie, J.R.,...Auguste, R.J. 2018. A field guide to the amphibians and reptiles of Trinidad and Tobago. Trinidad and Tobago Field Naturalists' Club. 336 pp. || Hayes, F.E., and Gabriel, R.L. 2019. Predation by a Boa Constrictor (Boa constrictor) on a Great Kiskadee (Pitangus sulphuratus) in Trinidad, W.I. Living World 2019: 47-48. || Auguste, R.J. and Fifi, A. 2021. Boa constrictor diet. Herpetological Review 52:146-147.

Sunday, February 28, 2021

A new species of frog re-described from Trinidad

Photo: (Elachistocleis nigrogularis sp nov). Photograph by Renoir Auguste. Every year, new species are being described for the first time, adding to the list of wildlife on Earth. In addition to new species being described (and discovered for the first time), some species are being re-described as new, distinct organisms. These new re-descriptions are based on a closer inspection of the organisms' DNA, morphology, and other biological characteristics. Over the past decade, new species have been re-described from Trinidad and Tobago. And now there is another. Narrow mouth frogs (in the genus Elachistocleis) are found across South America, and Trinidad. One of these narrow mouth Elachistocleis frogs was recently described as a new species, distinct from others in the same genus. The scientific name is Elachistocleis nigrogularis, and it got its name (nigrogularis) referring to its black throat that both the males and females have, a distinguishing feature compared to its cousins. This frog (seen in the photograph above), is active mainly at the start of the rainy season where it can be heard calling, which sounds like a long whistle-like call that can be heard just before heavy rains. One may have heard them while passing by the Aripo Savannas, Arena Forest, or Bush Bush Wildlife Sanctuary in Trinidad. These frogs feed on ants and termites and are important parts of the environment. They are the latest new species to be described from Trinidad and Tobago. They will not be the last! To read the scientific paper, here is the DOI link: 10.1007/s13127-021-00487-y or you can contact the Herpetology Group leader of the Trinidad and Tobago Field Naturalists' Club (ttfnc.org).

Tuesday, December 29, 2020

A new lizard recorded for Trinidad & the importance of Citizen Science

 

Mourning gecko (Lepidodactylus lugubris). Photo by Adam Fifi

Among exotic reptiles, lizards are the most abundant group introduced to new regions, and even to different countries. One particular group of lizards seem to drift far away from their native countries - Geckoes! No doubt, human facilitation through movement of goods and people have aided in the distribution of animals, including lizards. 

Trinidad and Tobago has had at least a half a dozen lizards introduced to the country. Most of these have been Anolis lizards (at least 6 species). However geckoes are about halfway behind with at least 3 new species to the country. One of these is the mourning gecko (Lepidodactylus lugubris). The gecko was first reported on the citizen science application iNaturalist, and have subsequently been found by others across the country. This short natural history note documents their distribution in the scientific literature for the first time, and commends the efforts of persons that took photos and uploaded to iNaturalist. 

If you don't use or are familiar with iNaturalist, it is highly recommended. Who knows, maybe you may photograph an animal in the country and it turns out to be a new record for the country!

Reference: 

Auguste, R.J., Fifi, A. 2020. Additional record of the invasive mourning gecko Lepidodactylus lugubris (Duméril and Bibron, 1836) from Trinidad and Tobago, with comments on citizen science observations. Herpetology Notes 13: 1111-1112 (link to pdf of paper here)



Cryptic diversity in the black-headed snake from Trinidad & Tobago?

Black-headed snake (Tantilla melanocephala). Photo by Renoir Auguste

Previous studies have shown that some widespread species are in fact cryptic species - or species that resemble each other superficially, but are actually two or more different species.  This aspect can have serious implications towards conservation of species, as each species has their own unique traits. Thus, studies examining the cryptic diversity in species is important for conservation management.

The black-headed snake (Tantilla melanocephala) is a widespread snake found across Central, and South America. It is also found on Trinidad and Tobago and southern Lesser Antilles in the Caribbean. A recent study examined the genetic materials and morphology of specimens from T&T and compared them to northern South American individuals. It was found that the populations on T&T are related to those on Venezuela - which is a common trait among many other species. Further studies are needed, but this one sets a landmark foundation to examine other individuals from across its range.

Reference

Jowers, M.J., Rivas, G.A., Jadin, R.C., Braswell, A.L., Auguste, R.J., Borzée, A., and Murphy, J.C. 2020. Unravelling the species diversity of a cryptozoic snake, Tantilla melanocephala, in its northern distribution with emphasis to the colonization of the Lesser Antilles. Amphibian and Reptile Conservation 14(3): 206-217 (pdf here)




Thursday, December 10, 2020

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/

Monday, December 7, 2020

Citizen Monitoring of Green Iguanas in Trinidad and Tobago

Green iguana (Iguana iguana). Photo by Renoir Auguste

 The green iguana (Iguana iguana) is widely distributed (ubiquitous) across Trinidad and Tobago. It can be found in forests as well as in urban gardens and parks. In Trinidad and Tobago they are hunted for their meat. Although the green iguana is perhaps very abundance currently, there have been no targeted efforts to document its distribution and abundance locally. This perhaps may be because of different reasons, with lack of funding being one of them. 

During the restrictions enforced by safety precautions for managing covid-19 spread, a call was made in April 2020 by the Trinidad and Tobago Field Naturalists' Club Herpetology Group Leader to Club members and members of the public across urban areas in Trinidad to document green iguanas from their backyard. Persons were reached out mainly using social media. During the very short period, over a hundred iguanas were reported from across urban areas in Trinidad which was published in the international journal Reptiles and Amphibians. This rapid assessment illustrates how citizen science can contribute to ecological data in a short time frame with limited expenses. Hopefully, the data can be used to better manage exploited green iguanas in urban areas in Trinidad, and provide a baseline for future studies on the exploited reptile.

Reference

Auguste, R.J. 2020. Using citizen science to rapidly determine the distribution of exploited green iguanas (Iguana iguana) across urban Trinidad and Tobago.  Reptiles & Amphibians 27(3): 419-421.

Link to paper here:

https://journals.ku.edu/reptilesandamphibians/article/view/14859