07/19/2024
Asheville Wildside Creature Feature!
White-lipped Pit Viper
(Trimeresurus albolabris)
In the year of our lord, 1798, French naturalist Bernard-Germaine-Ètienne de La Ville-sur-illon, comte de Lacépède (we are just going to call him 'Bernie') wrote the following.
"The species can undergo such a large number of modifications in its forms and qualities, that without losing its vital capacity, it may be, by its latest conformation and properties, farther removed from its original state than from a different species: it is in that case metamorphosed into a new species."
What Bernie was trying to convey, eleven years before Charles Darwin would even be born, was that he saw scientific evidence of speciation and evolution occurring within animal groups. In 1789, Bernie authored the tome 'Histoire naturelle des serpentes' an exhaustive examination of diverse snake species from Europe, and many regions that would one day become French colonies. Specifically, the area of Southeast Asia that today comprises the countries of Laos, Vietnam, and Cambodia. One group of snakes that was heavily represented was the arboreal pit vipers. Bernie named this genus Trimeresurus, and it was accepted in 1804. Even 220 years ago, it was evident that within this group of animals, there existed considerable minute variations that reflected geographical distribution. Just like the finches of the Galapagos, it was an excellent example of random mutations occurring within a population, some of those mutations being beneficial, and eventually leading to species diversification. During the 1800s, eleven new species would be listed in the genus, and today, 44 distinct species of Trimeresurus are recognized. Most are very similar animals, and the group is quite successful, with population densities throughout Southeast Asia and the Indopacific region.
Trimeresurus albolabris is widespread throughout tropical dry woodland, monsoon forests, and rainforest regions of Southeast Asia. From Nepal and east India, across southern China, south through Thailand, Vietnam, Myanmar, Malaysia, Laos, Cambodia, and stretching to Indonesia with insular populations in Sumatra, Java, Lombok, Sumbawa, Komodo, Flores, Sumba, Roti, Kisar, and the Wetar straights. Throughout this massive range, they overlap with many other species of Trimeresurus, and hybridization may also occur in some regions. These snakes are mostly nocturnal. During daylight hours, they find covered positions, forks in tree branches, or tangles of fallen limbs to conceal themselves from potential predators. At night, they perch in advantageous positions and ambush birds, bats, small mammals, frogs, and lizards.
The venom produced by these animals is predominantly hemotoxic. While many bites have been reported in Southeast Asia from snakes of this genus, fatalities are very rare. The species is sexually dimorphic, males are smaller than females, maturing around 18-24 inches in length and with prominent white lateral stripes extending from the labial scales down the length of the animal. Larger females can measure 30-36 inches and are mostly green with red striping on and around the tail.
Like other pit vipers, genus Trimeresurus possesses a deep loreal pit between the eyes and nostrils. This 'pit' structure is the external opening to a complex and incredibly sensitive infrared detection organ. The heat sensing organ is covered with a thin membrane loaded with nerve endings, which are packed with mitochondria that allow detection of thermal radiation. When this radiation is shed by endothermic animals or ectothermic animals that are warmer than their environment, the membranes can detect the slight changes against a background environment. With a pair of these pits, it creates a stereo effect that allows the snake to rapidly detect, predict direction, movement speed, and interpret range with incredible speed and precision. When deprived of sight and smell, many pit vipers have demonstrated the ability to accurately strike moving targets as little as 0.36 degrees Fahrenheit (0.2 degrees celsius) warmer than the environmental temperature.
Genus Trimeresurus are all viviparous, retaining soft shelled ova until the neonates are fully formed and giving birth to developed babies. They are mucus covered and will congregate in masses near the mother. They are capable of climbing, moving, and defending themselves immediately. They shed soon after emerging, and disperse into the forest to hunt small lizards and treefrogs until their growing bodies allow them to tackle larger prey.
The natural world is a wonderful and beautiful web of organisms and relationships. Our understanding of it is, like the very plants and animals themselves, ever evolving. As should our hobby and the way in which it is represented to non-keepers. I have seen dramatic changes in my twenty years working with these incredible animals, and the venomous snake hobby is one area that has transformed radically. Many states, counties, and cities have taken steps to restrict or even outright ban the keeping of venomous reptiles. Many of these restrictions are the result of poor keeping practices that have led to escapes, bites, hospitalizations, and even deaths. We MUST be good stewards of our hobby. We have to demonstrate responsible keeping practices, secure enclosures, proper handling and tool use, and not sensationalize the inherent danger of working with venomous animals. Just like keeping large hoofstock, big cats, bears, crocodilians, and other potentially dangerous animals, venomous snakes represent potential risks to keepers. It is our responsibility to demonstrate through our actions that these snakes can be maintained in a safe, ethical manner and that members of the general public are not put at risk by our love for these animals. One irresponsible keeper can easily undo the work of hundreds of hobbyists and breeders who have diligently maintained their collections for decades without incident.
To quote our boy Bernie up top, "The study of nature is a fertile and delightful occupation, which renews our mind and cheers our spirits." Amen, Bernie. Well said.