Late one spring night in 1887 in the Kakhyen Hills of Burma, 35-year-old Italian explorer Leonardo Fea crested a karst outcrop and entered a bamboo thicket. He barely noticed the rain, because before him lay a two-foot long snake of indescribable beauty. It was shiny, dark purplish-black and marked with thin, widely-spaced neon orange bands so bright they almost looked white. The head bore a striking symmetrical pattern of orange, gold, and black. When Fea picked the snake up, he saw that it had a plain purple belly. It appeared to be a harmless colubrid, and luckily for Fea, he wasn't bitten, so he had no opportunity to find out that it wasn't.
Fea was among the many European explorers and natural historians who were pouring into the newly-annexed nation of Burma, whose cultural roots date back to the 2nd century BCE. He collected thousands of vertebrates there for the Genoa Civic Museum, but perhaps none so unique or amazing as that snake. When Belgian-British herpetologist George Boulenger received a loan of Fea's reptiles from the museum, he declared of the single specimen "I may well say that Azemiops is the most interesting ophiological discovery made since that of Dinodipsas [Causus]1". Boulenger described it as a new genus and species in his 1888 report on Fea's expedition, writing "it affords me great pleasure to connect with [this snake] the name of the courageous and highly successful explorer to whom science is indebted for this and so many other additions." Azemiops feae was the first species named for Fea, who was soon to also receive the honors of an eponymous petrel, tree rat, and muntjac, collected with his "untiring zeal" in southeast Asia and the Cape Verde islands.
|Azemiops feae. Notice the enlarged head scales |
and the absence of a heat-sensing facial pit.
|This specimen's head shows more than the usual amount|
of white. In preservative, the head turns completely white,
causing some to call them "White-headed Vipers".
Fea's vipers are rare and difficult to keep in captivity. In 1986, the price list for Scales & Tails Trading Company in Hong Kong offered five Azemiops feae as "White Head Vipers" for $300 a piece, the most expensive item on the list. Observations of captive individuals indicate that these snakes do not tolerate dry conditions, and develop skin problems when maintained at less than 100% humidity. Ideal temperatures are between 60 and 68°F, surprisingly cool for a reptile (but a little warmer than those preferred by Rubber Boas). In the words of one reptile keeper, they are "so boring & difficult to keep" that he sent his off to a zoo. If widely held, this sentiment may actually bode well for Fea's vipers if it renders them unlikely to become overcollected for the pet trade, especially if the low demand can be met by captive breeding. Mating behavior involves courtship of females by males and is similar to that of other vipers in most respects. Fea's vipers lay small clutches of eggs, a characteristic they share with most viperines but not their closer relatives, the crotalines.
|Plate from Boulenger's 1888 Account of the Reptilia obtained in Burma, |
north of Tenasserim, by M. L. Fea, of the Genova Civic Museum
|Skull of a Fea's Viper, showing the solenoglyphous fang,|
the definitive viper characteristic.
How dangerous are Fea's vipers? Few bites have been reported, but these are described as "mild", causing few serious consequences. There are similarities between Fea's viper venom and that of viperines, especially Wagler's Temple Viper, except that Azemiops venom has no blood clotting, hemorrhagic, or muscle-destroying activity. The venom gland itself is similar to a viperine's, but Fea's viper fangs possess a ridge at the tip and a blade on the back seen only in some opisthoglyphous and atractaspid snakes. One venom component, dubbed azemiopsin, has been identified as a potential model in neurotransmitter research, adding to the pharmacopoeia of medicinally-useful compounds found in snake venom. Although discovered 125 years ago, Fea's viper has much still to teach us about evolution, neurology, and much else. Let us hope we can learn from it.
1 The genus Causus consists of six species of viper from sub-Saharan Africa commonly known as night adders. Night adders were once considered the most primitive vipers due to their round pupils and enlarged head scales, which is why Boulenger found them remarkable. They are oviparous and are now known to be more closely related to viperines than to Azemiops and crotaline vipers. Look out for an article on them up here one day!↩
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Life is Short, but Snakes are Long by Andrew M. Durso is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.