Sunday, February 28, 2021
Tuesday, December 29, 2020
|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!
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)
|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.
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
|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
|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.
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:
Friday, October 30, 2020
|Barbour's thin-toed frog (Leptodactylus insularum). Photo by Renoir Auguste|
Frogs are vitally important to ecosystems, and to people. Their importance in ecosystems stems from the roles they play acting as predator and prey to a variety of animals. Their ecological importance also benefits people, as frogs prey on insects, including pests to crops and mosquitoes. However frogs also play an important role in medicinal values. In particular, the peptides in frog skin secretions have been used to treat diseases, for example diabetes.
Trinidad and Tobago has at least 35 species of frogs (amphibians). Thus far, at least two frog species have shown to have peptides useful for medicine, including the paradoxical frog (Pseudis paradoxa), and the Trinidad leaf-nesting frog (Phyllomedusa trinitatis). Now, two more species can be added to the list. A recent published study by Barran and colleagues (2020) found antimicrobial resistant properties in two species. These are the Trinidadian thin-toed frog (Leptodactylus nesiotus), and Barbour's thin-toed frog (Leptodactylus insularum).
Barran and colleagues' study further exemplifies the importance of conserving frogs in Trinidad and Tobago, and all citizens should do their part by learning more about them, and conserving them for generations to come.
Citation: Barran, G.; Kolodziejek, J.; Coquet, L.; Leprince, J.; Jouenne, T.; Nowotny, N.; Conlon, J.M.; Mechkarska, M. Peptidomic Analysis of Skin Secretions of the Caribbean Frogs Leptodactylus insularum and Leptodactylus nesiotus (Leptodactylidae) Identifies an Ocellatin with Broad Spectrum Antimicrobial Activity. Antibiotics 2020, 9, 718.
Link to paper here: pdf
Wednesday, October 7, 2020
The brown vine snake from Trinidad and Tobago locally known as Horsewhip has recently been re-described as a new species based on genetic and morphological data, compared to other specimens from across the Americas. The research was lead by Jadin and colleagues and published this year. The snake's scientific name is Oxybelis rutherfordi, or commonly Rutherford's vine snake.
The species has been named in honour of Mike Rutherford, who was the former Curator of the University of the West Indies Zoology Museum, for his contributions to Zoology and Natural History in Trinidad and Tobago. Persons from Trinidad and Tobago that have participated in the annual Bioblitz or with the Trinidad and Tobago Field Naturalists' Club will be familiar with Mike. Congrats, Mike!
No doubt, new species of reptiles and amphibians will continue to be described in the country, which makes for exciting opportunities for young naturalists to get involved and passionate about wildlife.
Jadin et al. 2020. Not withering on the evolutionary vine: systematic revision of the Brown Vine Snake (Reptilia: Squamata: Oxybelis) from its northern distribution. Organisms Diversity & Evolution
Sunday, August 16, 2020
Monday, July 27, 2020
|House gecko (Hemidactylus mabouia). Photo by John Murphy|
For those of you living in Trinidad and Tobago, you may have heard an odd sound coming from your wall or roof at night. Chances are, it was an African House gecko (Hemidactylus mabouia).
Other common names include African wood-slave and twenty-four hours. (NB: A few different lizards are referred to as 24-hours in Trinidad, whereby when the lizard falls on you, you have 24-hours left to live - a common folklore in the country).
Here is a YouTube Link to what these geckos sound like: https://www.youtube.com/watch?v=7dP33YLo-KU (1 minute long, but can skip to 25 seconds). Have you heard this sound in your home? Let us know!
You can learn more about this lizard and the folklore of local reptiles in the "Field guide to the amphibians and reptiles of Trinidad and Tobago" available in most leading bookstores nationwide, or directly from the Trinidad and Tobago Field Naturalists' Club.
Tuesday, June 23, 2020
|Leaf anole (Anolis planiceps) gripping onto a plant. Photo by Renoir Auguste|
Some animals have shown the propensity to adapt to severe hurricane winds, allowing them to survive. One adept example can be seen in Anolis lizards or Anoles, which can be found on every Caribbean island.
Anoles are mostly small to semi-large lizards. They are found across the Caribbean and Americas and are important components of ecosystems, feeding on a variety of insects, and are food to a variety of birds and other animals. They are considered ideal organisms for studying biology, ecology, and adaptation (among other fields).
A study by Donihue et al. 2020 showed that Anoles have found a way to adapt to strong hurricane winds: by growing larger toepads! These toepads allow the small lizards to grip onto vegetation better, thus allowing them to not be blown away by strong winds. Not only are these lizards with larger toepads surviving hurricanes, for example hurricane Irma and Maria from 2017, their offspring are being born with large toepads as well (compared to other anoles not exposed to hurricanes).
It's amazing what we can learn from animals, such as anoles, about adaptation to global events. No doubt we can learn more from them, which hopefully will allow us to appreciate them more and improve our management of biodiversity conservation.
There are at least 8 types of Anoles in Trinidad and Tobago. To learn more about these Anoles found in T&T, do get yourself a copy of the field guide to the amphibians and reptiles of Trinidad and Tobago, available from the Trinidad and Tobago Field Naturalists' Club.
Thursday, June 4, 2020
|Tobago Glass Frog (Hyalinobatrachium orientale tobagoense) seen from below - translucent. Photo by Renoir Auguste|
Animals with transparent skin in nature are rare, and our understanding of the function of it is even rarer. One example of an animal with apparent transparent skin is the glass frog. They are found across Central and South America, as well as on the island of Tobago, north east of Venezuela. These frogs, as their name suggests, have skin where the organs, bones, and even eggs (in females) can be seen through their skin. However, only from their underside, and not their back (as seen in both photos in this post). Because of this, glass frogs are better defined as being translucent due to the dorsal pigmentation.
Scientists investigated whether the imperfect transparency (only the belly and not the back) acts as camouflage, and how effective it is. They found that the perceived luminance of the glass frogs changed depending on the background, which lowered detectability by predators, and increased survival, when compared to opaque (not able to see through) frogs. It also appears that the change was greatest for the legs, which surround the body at rest which hid the frogs even more, referred to as edge diffusion. No doubt this is probably why glass frogs are so difficult to find during the day when they are sleeping!
The Tobago Glass Frog shares these similar translucent features of other glass frogs across the region. To learn more about the local glass frogs in Tobago, including where to find them, check out the Field guide to the amphibians and reptiles of Trinidad and Tobago, available by the Trinidad and Tobago Field Naturalists' Club.
|Tobago Glass Frog seen from above - not translucent. Photo by Renoir Auguste|
Reference: Barnett et al. 2020. Imperfect transparency and camouflage in glass frogs. PNAS.