Category: Herpetozoa

Guest blog post: Unique feeding behaviour of Asian kukri snakes gutting frogs and toads

Guest blog post by Henrik Bringsøe

In September 2020, we reported the first evidence for a newly discovered behaviour in snakes, as we provided extensive photographic documentation, demonstrating a macabre feeding strategy of Asian kukri snakes of the species Oligodon fasciolatus, the Small-banded Kukri Snake: a snake cutting open the abdomen of a toad, inserting its head and pulling out the toad’s organs which are then swallowed.

A Small-banded Kukri Snake attacking a Painted Burrowing Frog, which is inflating its lungs. The snake makes rotations about its own longitudinal body axis (“death rolls”), as it is biting and holding the belly of the frog. Video by Navapol Komanasin.

This is done while the toad is alive and it may take several hours before it dies! We have now provided new evidence that two other species of kukri snakes also exhibit this highly unusual behaviour: Oligodon formosanus, the Taiwanese Kukri Snake, and Oligodon ocellatus, the Ocellated Kukri Snake. These three species are closely-related and belong to the same species group in the genus Oligodon.

On two occasions in Hong Kong, a Taiwanese Kukri Snake was observed eviscerating frogs of the species Kaloula pulchra, the Painted Burrowing Frog or Banded Bullfrog. In one case, the snake had cut open the belly of the frog and inserted its head deep into the frog’s abdomen. In this position, the snake performed repeated rotations about its own longitudinal body axis, also called “death rolls”! We believe that the purpose of these death rolls was to tear out organs to be subsequently swallowed. In the other case, the organs of the frog had been forced out of its abdomen.

A Taiwanese Kukri Snake with its head buried deep into the abdomen of a Painted Burrowing Frog. Initially, the frog moves its long fourth toe of the left hind foot up and down 21 times. During the subsequent active struggle, the snake makes three “death rolls”. Video by Jonathan Rotbart.

A Small-banded Kukri Snake was also observed eating a Painted Burrowing Frog in Northeast Thailand, but it swallowed the frog whole. That snake also performed death rolls, although we have never before seen that behaviour in this species of kukri snake (this species was treated in our 2020 paper). This frog is not considered toxic and is also eaten by other snakes. We believe that prey size is crucial in determining whether the gape width allows large prey to be swallowed whole by kukri snakes. If the prey is too large, the snake may eviscerate a frog or toad, in order to swallow the organs. Afterwards, the snake will perhaps be able to swallow the rest of the frog or toad.

In another new paper, we describe and illustrate the Ocellated Kukri Snake eating the toxic toad Asian Black-spotted Toad (Duttaphrynus melanostictus) in Vietnam. Initially, the large snake’s head was buried past its eyes into the abdomen of the toad, but eventually the snake swallowed the toad whole despite its toxicity. We interpret this behaviour that kukri snakes are in fact resistant to the toads’ cardiac glycoside toxins. Furthermore, toads are only eviscerated if they prove too large to be swallowed whole.

An Ocellated Kukri Snake first pierced this poisonous Asian common toad and buried its head deeply into the abdomen of the amphibian, as it was probably eating the organs. However, as seen in the photo, the kukri snake proceeded to swallow the toad whole. 
Photo by James Holden.

We suggest that the unique behaviour of eviscerating frogs and toads and eating their organs may have evolved specifically in a group of kukri snakes named the Oligodon cyclurus group or clade because it has now been recorded in three of its species, namely Oligodon fasciolatus, Oligodon formosanus and Oligodon ocellatus. We hope that future observations may uncover additional aspects of the fascinating feeding habits of kukri snakes though we may indeed call them gruesome.

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See more video recordings of the snakes’ unique, even if quite gruesome, behaviours provided as supplementary files to one of the discussed research papers.

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Research papers: 

Bringsøe H, Suthanthangjai M, Suthanthangjai W, Lodder J, Komanasin N (2021) Gruesome twosome kukri rippers: Oligodon formosanus (Günther, 1872) and O. fasciolatus (Günther, 1864) eat Kaloula pulchra Gray, 1831 either by eviscerating or swallowing whole. Herpetozoa 34: 49-55. https://doi.org/10.3897/herpetozoa.34.e62688

Bringsøe H, Holden J (2021) Yet another kukri snake piercing an anuran abdomen: Oligodon ocellatus (Morice, 1875) eats Duttaphrynus melanostictus (Schneider, 1799) in Vietnam. Herpetozoa 34: 57-59. https://doi.org/10.3897/herpetozoa.34.e62689

Guest blog post: Snakes disembowel and feed on the organs of living toads in a first for science

A Small-banded kukri snake with its head inserted through the right side of the abdomen of an Asian black-spotted toad, in order to extract and eat the organs. The upper part of the front leg is covered by foaming blood, likewise, mixed with air bubbles from the collapsed lung.
Photo by Winai Suthanthangjai

Guest blog post by Henrik Bringsøe

Our observations on the quite small-bodied Asian kukri snakes in Thailand have documented a feeding behaviour which differs from anything ever described in snakes. 

Normally, snakes would swallow their prey whole. However, this particular species: the Small-banded Kukri Snake (Oligodon fasciolatus), would instead use its enlarged posterior maxillary teeth to cut open the abdomen of large poisonous toads, then inserts its entire head into the cavity to pull out and eat the organs one by one, while the prey is still alive! 

During those macabre attacks, we managed to capture on camera three times, the toads struggled vigorously to escape and avoid being eviscerated alive, but, on all occasions, this was in vain. The fights we saw lasted for up to a few hours, depending on the organs the snake would pull out first.

The toads observed belong to the quite common species called Asian Black-spotted Toad (Duttaphrynus melanostictus), which is known to secrete a potent toxin from their prominent parotid glands, located on the neck and all over the back. Could it be that the snakes have adopted this sophisticated and gory approach to avoid being poisoned?

In a fourth, and equally important, case, an adult kukri snake attacked a somewhat smaller individual of the same toad species. However, this time, the snake swallowed the entire toad. Why did the snake swallow the juvenile toad, we still don’t know. Perhaps smaller toads are less toxic than adults? Or, could it be that kukri snakes are indeed resistant to the Asian Black-spotted toad’s poison, yet the large size of the adult toads prevented the snakes from swallowing them in the three afore-mentioned cases?

Adult Small-banded kukri snake swallowing a large Asian black-spotted toad juvenile
(Phitsanulok, Thailand, 5 June 2020).
Photo by Kanjana Nimnuam

At present, we cannot answer any of these questions, but we will continue to observe and report on these fascinating snakes in the hope that we will uncover further interesting aspects of their biology.

Perhaps you’d be pleased to know that kukri snakes are, thankfully, harmless to humans. However, I wouldn’t recommend being bitten by one of those. The thing is that they can inflict large wounds that bleed for hours, because of the anticoagulant agent these snakes inject into the victim’s bloodstream. Their teeth are designed to inflict lacerations rather than punctures, so your finger would feel as if cut apart! This secretion, produced by two glands, called Duvernoy’s glands and located behind the eyes of the snakes, are likely beneficial while the snakes spend hours extracting toad organs.

Small-banded kukri snake having managed to slit through the left side of the abdomen of the toad underneath the left front leg. Two liver lobes next to the already dead toad are visible.
(Loei, Thailand, 9 August 2016).
Photo by Winai Suthanthangjai

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Publication:

Bringsøe H, Suthanthangjai M, Suthanthangjai W, Nimnuam K (2020) Eviscerated alive: Novel and macabre feeding strategy in Oligodon fasciolatus (Günther, 1864) eating organs of Duttaphrynus melanostictus (Schneider, 1799) in Thailand. Herpetozoa 33: 157-163. https://doi.org/10.3897/herpetozoa.33.e57096

‘Social distancing’ saves frogs: New approach to identify individual frogs noninvasively

aitik Patel and Dr Abhijit Das of the Wildlife Institute of India came up with one of the very first non-invasive approaches to identify individual frogs using photos from their natural habitats, which are then processed with the animal recognition software HotSpotter. Their unique method is described in the open-access, peer-reviewed scientific journal Herpetozoa.

A Beautiful stream frog (Amolops formosus) in a Himalayan torrent stream
Photo by Naitik Patel

Globally, 41% amphibian species are regarded as threatened with extinction. However, when it comes to the case of India, the majority of the species falls in the Data Deficient group, according to the criteria of the International Union for Conservation of Nature‘s (IUCN) Red List of Threatened Species.

This means that we hardly have any population data for Indian amphibians, which leads to a serious conservation bottleneck, especially when you are dealing with elusive herpiles. Therefore, there is the pressing priority to obtain demographic trends to prompt and support conservation actions for endemic and habitat-dependent species.

While demographics of natural populations is best estimated with the mark-recapture technique, used in animals, where individuals have distinct body markings, such as the stripes in a tiger, the dots in a whale shark and the fingerprints in a human. In the meantime, while frogs are well known for their individual-specific markings and colour patterns, this kind of technique has never been used in amphibians, even though they have long been recognised as some of the most vulnerable animals on Earth.

On the other hand, it is hardly possible to capture and mark individual frogs in the wild. So, Naitik Patel and Dr Abhijit Das of the Wildlife Institute of India came up with one of the very first non-invasive approaches to identify individual frogs using photos from their natural habitats, which are then processed with the animal recognition software HotSpotter. Their unique method is described in the open-access, peer-reviewed scientific journal Herpetozoa.

“Capturing each frog is not possible in the field, so to address this problem, we conducted a short study on Beautiful stream frogs (Amolops formosus), a species that, just like many other amphibians, has variable body markings amongst individuals. As this species inhabits the Himalayan torrent stream, which is difficult to access, we tried our best to photograph each frog from a distance to avoid any kind of physical contact,”

explains Naitik Patel, a PhD student at the Wildlife Institute of India.

A Beautiful stream frog (Amolops formosus)
Photo by Abhijit Das

Having concluded their study with a success rate of 94.3%, the research team is hopeful that their protocol could be effectively implemented in rapid population estimation for many endangered species of frogs.

“We conducted photographic documentation to capture the unique markings of each frog, and then compared them, using computer-assisted individual identification. With this method, the number of individuals can be counted to estimate the population structure. This study is exceptional, owing to the minimal disturbance it causes to the frogs. Such a technique has rarely been tried on amphibians and is a promising method to estimate their numbers. It can also be used in citizen science projects,”

comments senior scientist Dr Abhijit Das.

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Original source:

Patel NG, Das A (2020) Shot the spots: A reliable field method for individual identification of Amolops formosus (Anura, Ranidae). Herpetozoa 33: 7-15. https://doi.org/10.3897/herpetozoa.33.e47279

Reptile poaching in Balochistan (Pakistan) is on a decreasing trend but still troublesome

Since 2013, following a strict enforcement of provincial wildlife legislation in the less studied regions of Asia, the overall trend of illegal reptile poaching is steadily decreasing. Despite that, the issue is not yet resolved and poached reptiles are largely destined not only for the international pet trade, but also utilised in folk medicines and snake charmer shows, according to a recent study, published in the open-access journal Herpetozoa.

Since 2013, following a strict enforcement of provincial wildlife legislation in the less studied regions of Asia, the overall trend of illegal reptile poaching is steadily decreasing. But it’s too early to claim that the issue is solved. Poached reptiles are largely destined not only for the pet trade, but also folk medicines and snake charmer shows, according to the recent study led by the scientists from the Pakistan Museum of Natural History and the University of Peshawar published in the open-access journal Herpetozoa.

For the first time, the exploitation of reptiles for the pet trade has come to the attention of the public in the late 1960s. In general, illegal poaching is one of the problems we still face a lot all over the world, despite strict restrictions which are coming in force massively over the last decades. The wildlife trade leads not only to biodiversity loss (through capture of protected species), but also threatens with a possible spread of animal-borne diseases, due to interspecies contact at pet and folk medicine markets. The case of the recent COVID-19 pandemic gives a lesson to learn, and in order to stop further occurrences, a focus on law-enforcement activities should be brought to wildlife trade hotspots.

In the particular case of Pakistan, a country with high species diversity of reptiles, still very little is known about the links between illegal wildlife trade and wildlife decline. The illegal poaching and trade in Pakistan are largely undocumented and it’s difficult to bring accurate data since the trade involves many channels and follows informal networks. There is marginal information available about the medicinal use of wild flora and fauna for some parts of Pakistan, but there is no report on the commercialisation, harvest, market dynamics and conservation impact of these activities.

Since 2013, a number of confiscations of different reptile species and their parts from Pakistani nationals have been reported widely from across the country, which resulted in the enforcement of legislations regarding the wildlife trade in Pakistan.

An international team of researchers, led by Dr. Rafaqat Masroor from Pakistan Museum of Natural History investigated the extent of illegal reptile collection in southwestern Balochistan. Scientists tried to determine what impact these activities might have on the wild populations.


A topographic map of southwestern Balochistan showing visit sites in Chagai, Nushki, Panjgur, Kharan and Washuk districts.
Credit: Rafaqat Masroor
License: CC-BY 4.0

The field trips, conducted in 2013-2017, targeted Chagai, Nushki, Panjgur, Kharan and Washuk districts in Balochistan province. Over those years, scientists interviewed 73 illegal collectors. Most of the collectors worked in groups, consisting of males, aged between 14 to 50 years.

“They were all illiterate and their sole livelihood was based on reptile poaching, trade, and street shows. These collectors were well-organized and had trapping equipment for the collection of reptiles. […] These groups were locally known as “jogeez”, who mainly originated from Sindh Province and included snake charmers, having their roots deep with the local hakeems (herbal medicine practitioners) and wildlife traders, businessmen and exporters based at Karachi city. […] We often observed local people killing lizards and snakes, mostly for fear of venom and part for fun and centuries-old myths”,

share Dr. Masroor.

A total number of illegally poached reptiles, recorded during the investigation, results in 5,369 specimens representing 19 species. All of them had already been declared Protected under Schedule-III of the Balochistan Provincial Wildlife Act.

A view of live reptiles. Lytorhynchus maynardi and Eryx tataricus speciosus, the two rarely encountered snakes inside the locally-made boxes.
Credit: Rafaqat Masroor
License: CC-BY 4.0

Amongst the reasons for the province of Balochistan to remain unexplored might have been the lack of government environmental and wildlife protection agencies, lack of resources and specialists of high qualification in the provincial wildlife, forest and environment departments, as well as geopolitical position and remoteness of vast tracts of areas.

 Number of specimens collected against the number of
individuals (illegal collectors).
Credit: Rafaqat Masroor
License: CC-BY 4.0

Scientists call for the provincial and federal government to take action and elaborate a specific strategy for the conservation of endemic and threatened species as a part of the country’s natural heritage both in southwestern Balochistan and whole Pakistan. The conservation plan needs to be consulted with specialists in the respective fields, in order to avoid incompetence.

Also, the research group suggests to strictly ban illegal poaching of venomous snakes for the purpose of venom extraction.

What is important to remember is that Balochistan represents one of the most important areas of Asia with a high number of endemic reptile species. The illegal capture of these species presents a threat to the poorly documented animals. Even though the current trend for captured reptiles is decreasing, more actions are needed, in order to ensure the safety of the biodiversity of the region.

Contact:

Dr. Rafaqat Masroor
Email: rafaqat.masroor78@gmail.com

Original source:

Masroor R, Khisroon M, Jablonski D (2020) A case study on illegal reptile poaching from Balochistan, Pakistan. Herpetozoa 33: 67-75. https://doi.org/10.3897/herpetozoa.33.e51690

Austrian Herpetological Society’s journal Herpetozoa moves to Pensoft’s ARPHA platform

Newly published research articles demonstrate numerous innovative features to the benefit of readers, authors and all other users

Published since 1988 by the Austrian Herpetological Society (ÖGH, Österreichische Gesellschaft für Herpetologie), the renowned peer-reviewed, open-access Herpetozoa is added to the growing portfolio of international scientific journals published on the ARPHA scholarly platform, as a result of a new partnership with scholarly publisher and technology provider Pensoft.

Follow Herpetozoa on Twitter and Facebook.

As before, Herpetozoa welcomes original research articles, short contributions and reviews covering all aspects of the study of amphibians and reptiles. The papers are published in English, whereas a translation of the abstract into German may also be included. The journal operates a single-blind peer review policy.

Thanks to the fast-track and convenient publishing provided by ARPHA, each manuscript is carried through all stages from submission and reviewing to dissemination and archiving without ever leaving the platform’s collaboration-friendly online environment.

Right underneath the new sleek look and feel welcoming users from the journal’s homepage, there are a lot of high-tech perks to benefit authors, readers, reviewers and editors alike.

Furthermore, all publications are available in three formats (PDF, XML, HTML), complete with a whole set of semantic enhancements, so that the articles are easy to find, access and harvest by both humans and machines.


Editor-in-Chief of Herpetozoa, Dr Günter Gollmann states:

“We decided to move to Open Access online publishing to increase the visibility of our journal, and to speed up the publication process. The highly attractive presentation provided by Pensoft should boost attention for the papers we publish. While Herpetozoa welcomes contributions of any length on all topics in herpetology, I hope that authors will appreciate the suitability of the new format for data-rich studies in natural history. Such research is often dismissed as “too descriptive” by other international journals, but is essential for conservation of biodiversity.”

ARPHA’s and Pensoft’s founder and CEO Prof Lyubomir Penev says:

“I am pleased to see Herpetozoa having found its new home on the ARPHA platform amongst all Pensoft journals and other highly reputed academic titles from around the globe. With our own strong background in zoological sciences, I am certain that our partnership with Herpetozoa will be quick to prove fruitful to both of us, but most importantly, to all readers, authors, editors and reviewers alike.”

With its move to the open-access, technologically advanced scholarly publishing platform, Herpetozoa lines up next to historical and well-known society journals, including Deutsche Entomologische Zeitschrift, Alpine Entomology (previously Journal of the Swiss Entomological Society), Journal of Hymenoptera Research, Zoologia and others, which have all chosen to modernise with the help of ARPHA.

What’s new on Herpetozoa?

Amongst the first batch of articles published in Herpetozoa in partnership with ARPHA/Pensoft, there is an Italian study tracking the long-disputed origin of the Mediterranean-native common chameleon (Chamaeleo chamaeleo) back to its ancestors in North Africa and the Middle East. Another paper by a research team from Romania compares the effects of carnivore, vegetarian and omnivorous diets on the growth, development and mortality in tadpoles of the common toad. In their study of the South American frog species Leptodactylus fuscus, scientists from Universidade Federal de Mato Grosso do Sul (Brazil) compare the diet of a population living in the wild with another one, which inhabits an urban environment. Their aim was to determine the impact urbanisation could be having on this otherwise abundant amphibian.

Distribution of the common chameleon in Salento (southern Italy) in 2018. Black dots represent observation localities (Basso et al. 2019).
Study openly accessible at:
https://doi.org/10.3897/herpetozoa.32.e35611

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Herpetozoa is indexed in Biological Abstracts; BIOSIS (Previews); Current Contents – Agricultural, Science Citation Index (Expanded); Web of Science; Zoological Record (Plus). Currently, its Journal Impact Factor stands at 1.125.

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About the Austrian Herpetological Society:

The Austrian Herpetological Society (Österreichische Gesellschaft für Herpetologie, ÖGH) was founded in 1984 to advance all branches of herpetology. The society supports scientific research and promotes conservation of amphibians and reptiles, as well as their habitats. To raise public awareness of these animal groups, ÖGH organizes meetings and excursions and publishes the journals Herpetozoa and ÖGH-Aktuell.