A Mouth Gaping Viper - Observation of the Week, 1/13/19

This “yawning” bamboo viper, seen in India by @prasannaparab, is our Observation of the Week!

“When I was in high school I used to collect nature and wildlife related newspaper cuttings, and also got hold of a few old National Geographic magazines, which helped in developing my interest on this subject,” says Prasanna Parab. “At that time, going into the wild or nature watching was just an unknown domain at home.”

He says that mentors like Paresh Porob (Range Forest Officer, Goa (India)) and Shambhu M V (Indian Forest Service) “sensitized me about nature, provided me the opportunity and inculcated the essential discipline and patience required for documenting natural history, this presented a plethora of opportunities for me to travel in the wild.” Prasanna began photographing butterflies - his photo of which have been used for the management plan of the Netravali Wildlife Sanctuary, where he has been named an Honorary Wildlife Warden - but is now also taking photos of birds, arachnids, orchids, and more.

Prasanna encountered the above snake back in 2014 while visiting Netravali Wildlife Sanctuary with Honorable Wildlife Warden Benhail Antao and Louise Remedios E Antao and tells me

we sighted this bamboo viper perched on a stick near a stream in an evergreen forest. Since none of us had a macro lens, we patiently watched this for 5-10 minutes, flickering its tongue with very slow movement. Suddenly, I saw it slowly opening its mouth, I was far away owing to the fact that I had a Canon 100-400mm tele lens; I quickly managed to snap 6 sequential images of this yawning behavior.

While the viper might appear to be baring its fangs in preparation to bite or at least scare off a threat, that’s likely not the case. I consulted with NHMLA herpetologist Dr. Greg Pauly (@gregpauly) and he was sent me an explanatory list of four probable reasons a snake might mouth gape (aka yawn):

1) Stretching fangs and jaws after eating a large meal. This is basically just getting everything back into a comfortable position. Owners of pet snakes will be quite familiar with this. Sometimes people think this is because they need to reposition their jaws after "unhinging" them, but of course snakes don't unhinge their jaws. That's just a common misconception.

2) Stretching fangs and jaw musculature in preparation for eating a large meal.

3) Drawing in chemicals that can contact the vomeronasal organ.

4) In some species, a wide open mouth is used as a threat/warning display. This is common in cottonmouths and parrot snakes.

5) There are certainly other reasons still awaiting to be discovered. Owners of pet snakes will have witnessed their snakes yawn in situations that don't fit into the above categories. For example, I think snakes sometimes yawn just to stretch critically important muscles and joints that don't get much day-to-day use otherwise. But nobody has really demonstrated this.   

Dr. Pauly believes this bamboo viper is likely opening its mouth for reason number 3 or possibly 5, and is not aware of this species using it as a threat display.

This species of viper is found in southern India, often among bamboo, and is known to prey on birds, lizards, and other small animals. It should not be confused with other members of its genus, some of which are also commonly called bamboo vipers. Like all vipers this species has front fangs (shown wonderfully in Prasanna’s photo) which can fold back when not in use, and its venom is primarily hemotoxic, meaning it damages and disrupts the circulatory system. Members of the other major venomous snake family, Elapidae (cobras, mambas, most sea snakes, among others), have fixed front fangs and their venom is generally neurotoxic, meaning it disrupts the nervous system.

While he has been photographing wildlife for many years, Prasanna (above) tells me me he only recently discovered iNaturalist while at “the Spider India Meet 2018 at Amba Ghat (Maharashtra, India) organized by Siddharth Kulkarni (The George Washington University, Washington DC) and Dr. Atul Vartak.” He attended a talk by Rohit George (@rohitmg) that covered citizen science and soon started looking into iNat. He says, “I went through the website several times and noticed that a lot of knowledge is being shared and circulated which can aid science in a huge way, thus prompting me to make more keen observations and share them on iNaturalist.” He’s currently posting both his past observations (like this one) and present observations here.

- by Tony Iwane


- Nice article about Siddharth Kulkarni and Dr. Atul Vartak’s documenting of a new spider species in India. 

- Here’s a New York Times column featuring Rohit George and an amazing spider-mimicking moth he found.

Posted by tiwane tiwane, January 14, 2019 05:23 AM

Comments

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Great photo! How fortunate you are to have such wonderful mentors. Keep those pictures coming.

Posted by pam-piombino about 1 month ago (Flag)
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Fantastic photograph!

Posted by lonnyholmes about 1 month ago (Flag)
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Excellent photograph and really good write-up on the reasons for this 'gaping' -- well done!

Posted by sambiology about 1 month ago (Flag)
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Cool!

Posted by bluejay2007 about 1 month ago (Flag)

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