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.

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.

New Publication

 

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

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.

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.

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).