Snakes long-lost

Click here to read this post in Spanish!
Haga clic aquí para leer este blog en español!

Alternate title suggested by Mike Pingleton: Not all who slither are lost

Clarión Nightsnake (Hypsiglena unaocularis)
Photograph from Mulcahy et al. 2014

Just over one year ago, a team of scientists from the Smithsonian and the Red de Interacciones Multitróficas rediscovered a species of nightsnake (genus Hypsiglena) on remote Clarión Island in the eastern Pacific Ocean, over 400 miles southwest of Cabo San Lucas. Called the Clarión Nightsnake (Hypsiglena unaocularus), it was originally discovered by the renowned American naturalist William Beebe in 1936, during a nocturnal sea turtle nesting survey. Because Clarión Island is only accessible via military escort, biologists have not visited the island frequently since Beebe's time, and in 1955 herpetologist Bayard Brattstrom suggested that perhaps Beebe's locality information had been an error, since only a single specimen existed and several other Clarión Island expeditions had not turned up another. However, the type specimen collected by Beebe, resting in the herpetology collection of New York's American Museum of Natural History, was sufficiently distinct from any other Hypsiglena specimen that it prompted herp phylogeographer Dan Mulcahy to reexamine Beebe's book and field notes, which contained a pretty clear description of the circumstances under which Beebe found the snake:

“We walked on, flashing the light all around. Not far from the water on the black lava 

I saw a small dark brown snake. It seemed to be unlike the one I had found in daylight, 

having lines of black spots on the body, so I picked it up and cached it in my shirt.” 

(p. 282 of Zaca Venture)

Location of Clarión Is.
From Mulcahy et al. 2014
Click to enlarge

As their name implies, Nightsnakes mostly come out at night (although I found one in southern Utah at about 9:30 in the morning a few weeks ago), and even then they are normally only active under certain conditions - in particular, they prefer to be active when there is not much moonlight, such as on cloudy nights or when the moon is new. Even if one is specifically searching for Nightsnakes, they can be difficult to find. Combined with their generally secretive nature, this could explain the failure of several Clarión Island expeditions to find the Clarión Nightsnake - until Mulcahy's expedition in May of 2013, which found 11 individuals in 15 days. Using phylogenetics, they determined that the Clarión Nightsnake is most closely related to the Santa Catalina Nightsnake (H. catalinae), which is found on Santa Catalina Island in the Gulf of California (which is not the same as the well-known Santa Catalina Island off of the US state of California). Nightsnakes are found all around the shoreline of the Gulf of California, and they are obviously exceptional over-water dispersers, because they occur on many of the islands in that region as well.

This remarkable story of rediscovery is a testament to the kind of attention to detail that it takes to be a good natural historian, but it's not the only species of snake that has been rediscovered many years after its initial description. Here are a few others:

Angel’s Stream Snake (Paratapinophis praemaxillaris)
Photograph from Murphy et al. 2008

Angel’s Stream Snake (Paratapinophis praemaxillaris) was described from two newborn specimens from northern Laos in 1929. At that time it was placed into a new genus because of an unusual process on its nose, but a few years later it was moved into the cosmopolitan genus Opisthotropis. Two more specimens were collected in the 1980s, but it wasn't until 2008, when five adult specimens were collected from a pool at the base of a waterfall on the Nan River in northern Thailand, that it became clear that the nose structure was actually an egg tooth, a structure normally lost a few days after hatching. At that time, Paratapinophis was placed back into its own genus because of several other formerly-overlooked unique features, including sexually dimorphic color, pattern, and scale ornamentation. Like most other natricines, this species eats fishes.

Chersodromus rubriventris
Photograph from Ramírez-Bautista et al. 2013

Chersodromus rubriventris, the Redbelly Earth Runner, was discovered in a cloud forest in San Luis Potosí, Mexico, just after the end of World War II and described a few years later by American herpetologist and spy Edward H. Taylor, who also used his biology as a cover for work in the Philippines, Russia, and Sri Lanka during both world wars. Two other specimens, one from the late 1960s and the other from the early 1980s, were known, but in 2013, a team of herpetologists from the Universidad Autónoma del Estado de Hidalgo found three individuals in a cloud forest in nearby Hidalgo, doubling the number of specimens and photographing the snake alive for the first time. Stomach contents included beetle larvae and ants, both of which are unusual prey for a dipsadid snake.

Atractus wagleri
Photograph from Passos & Arredondo 2009

The genus Atractus, a group of burrowing snakes found from Panama to Argentina, is the most diverse alethinophidian snake genus, with over 130 species, most of which are only known from a few specimens. Recently Paulo Passos of the Brazilian National Museum matched up several previously mis- or unidentified Atractus specimens in South American museums with their species, constituting rediscoveries of sorts. For example, Wagler's Ground Snake (Atractus wagleri) was described in 1945 from a single specimen from western Colombia, and that specimen was lost in a fire in 1948. In 2009 Passos located three additional specimens of this poorly known snake in museums in Colombia. Another species, the Modest Ground Snake (Atractus modestus), was described in 1894 by the great Belgian zoologist George Boulenger, from a single specimen from western Ecuador. In 2007 Passos located more specimens in Ecuadorian museums, expanding the range of the species across most of the country. Although species of Atractus are seemingly quite rare, occurring at high elevations and having secretive fossorial habitats, a large number of Atractus specimens remain misidentified or unidentified in herpetological collections, so our knowledge of these snakes stands to improve dramatically as these are examined and described.

Argus Snail Sucker (Sibon argus)

The Lichen-coloured or Argus Snail Sucker (Sibon argus) is an extremely slender arboreal dipsadine snake with eye-like ("ocellate") spots. It was originally described from a single specimen from southeastern Costa Rica in 1876, by renowned paleontologist Edward Drinker Cope (who feuded with O.C. Marsh in the "Bone Wars" over who could discover more dinosaurs, the subject of an upcoming film starring Steve Carrell as Cope). The validity of the species was uncertain because of the subsequent description of other gracile snakes with ocellated patterns from the same region. In his classic revision of Neotropical snail- and slug-eating snakes, James Peters suggested that Cope's specimen might be aberrant, or perhaps that it represented one half of a species with strong sexual dimorphism (which is rare in snakes), because the only known S. argus specimen  was a male, and another species, Sibon longifrenis, was known at the time from just two specimens, both females. Males and females of the same species had been described as separate species before. Ultimately, Peters decided that the two species were probably different, and he was proven right in 1992, when tropical herpetologist Jay Savage was preparing his opus on Costa Rican herpetofauna. Savage discovered both male and female specimens that best matched Cope's 1876 S. argus in the collections of the University of Kansas and the Universidad de Costa Rica. The snakes had been collected in evergreen forests in Panama and Costa Rica, near the type locality of S. argus. With Roy McDiarmid, Savage redescribed the species, which has become much more well-known since. A recent study by Julie Ray and colleagues documented a more diverse diet for this species than previously expected, including other gooey prey such as oligochaete worms and frog eggs. Unfortunately for Sibon argus, both of these prey types are in decline in the neotropics, the worms due to overcollection of their bromeliad homes for horticulture, and the amphibians due to the devastating effects of the amphibian chytrid fungus Batrachochytrium dendrobatidis.

Brygophis coulangesi
Photograph from Andreone & Raxworthy 1998

Other examples of rediscovered snakes abound. The Uluguru Worm Snake (Letheobia uluguruensis) was described from four specimens collected in 1926 from the Uluguru Mountains of eastern Tanzania, a mountain range with dozens of endemic species, and was not seen again until 2004, when four were dug up by local people employed by a group of herpetologists from the London Natural History Museum and the University of Glasgow to search for caecilians. Another blindsnake, Typhlops tasymicris, was rediscovered on Union Island, St. Vincent and the Grenadines, in 2010. An entire genus of blindsnake, Xenotyphlops, was rediscovered in Madagascar, in 2007, 102 years after it's description. A rare sea snake, Hydrophis parviceps, was originally collected by the Danish research vessel Dana and described in 1935 and was seen again only once in 1960 until three turned up in fisheries bycatch off of Vietnam in 2001. Another species of rare sea snake, H. bituberculatus, was rediscovered off Sri Lanka in the late 1980s, over 100 years after the first one was collected (although the fishermen who collected the specimen were so secretive that they refused to divulge the location). One of the rarest snakes in Madagascar, a slow-moving reddish-orange species called Brygophis coulangesi, was first collected in 1968, when one fell from a tree and vomited up a chameleon, with a second specimen found on a cloudy, rainy night during a rain forest survey in 1998, over 300 miles to the north of the first. A second specimen of another Malagasy lamprophiid, Alluaudina mocquardi, was discovered in a pitch-black cave in northern Madagascar in 1982, 50 years after the first was found in a different cave nearby. I don't think any more have been found since, so this one should be getting ready to be rediscovered again soon (edit: City University of New York snake biologist Frank Burbrink informed me that on his recent trip to Madagascar they turned up an Alluaudina mocquardi in tsingy rock at Ankarana - see photo here)!

March 2010 Herp. Review cover
featuring Crotalus lannomi

A high-profile rediscovery graced the cover of the March 2010 issue of the journal Herpetological Review, which featured a photograph of a long-sought-after species of rattlesnake, the Autlán Long-tailed Rattlesnake (Crotalus lannomi). Discovered in the summer of 1966 by Joseph Lannom, C. lannomi became sort of a “holy grail” of rattlesnakes in the decades that followed, as numerous herpetologists ventured into the mountains of western Jalisco in search of it. They were stymied by heavy fog and dangerous flooding, roads with treacherous curves and highway robberies, and drug-related violence. In 2008, five specimens of C. lannomi were found in the foothills of Colima, roughly 50 km from the type locality in Jalisco, in some of Mexico's most pristine forest habitat.

Although most of this was new to me, I've actually written about a different rediscovered viper before, the Spider-tailed Adder (Pseoducerastes urarachnoides) of Iran, which was discovered in 1968 and was at first thought to have either a tumor, a congenital defect, or a growth caused by a parasite, or maybe a spider clinging to its tail (turns out its tail is modified into a lure to attract spider-eating birds). Also, in one of my first articles, I wrote about the South Florida Rainbow Snake (Farancia erytrogramma seminola), described by Wilfred T. Neill in 1964 from Fisheating Creek in Glades County near Lake Okeechobee, Florida, and presumed extinct, never seen again since. To the best of my knowledge this subspecies has yet to be rediscovered, despite a $500 reward from the Center for Snake Conservation and Center for Biological Diversity. (Edit: a diligent reader reminded me that I also wrote about another snake that hasn't been seen since 1975 in one of my earliest articles, the Round Island Burrowing Boa, Bolyeria multocarinata).

Undoubtedly there are numerous snake species left to be discovered and rediscovered, and in many cases almost nobody's out there looking. The Reptile Database has predicted that the total number of described reptile species will surpass 10,000 in 2014, and that non-avian reptiles will perhaps eclipse birds in diversity soon after that. With snakes currently at 3,466, representing just over one third of reptiles, maybe you will be the next to rediscover a snake thought lost!

ACKNOWLEDGMENTS

Thanks to Dan Mulcahy and Don Filipiak for the use of their photographs.

REFERENCES

Andreone, F. and C. Raxworthy. 1998. The colubrid snake Brygophis coulangesi (Domergue 1988) rediscovered in north-eastern Madagascar. Tropical Zoology 11:249-257 <link>

Beebe, CW. 1938. Zaca Venture. Harcourt, Brace and Co. Inc., New York <link>

Cope, E. D. 1875. On the batrachia and reptilia of Costa Rica : With notes on the herpetology and ichthyology of Nicaragua and Peru. Journal of the Academy of Natural Sciences Philadelphia 2:93-157 <link>

Gower, D. J., S. P. Loader, and M. Wilkinson. 2004. Assessing the conservation status of soil‐dwelling vertebrates: Insights from the rediscovery of Typhlops uluguruensis (Reptilia: Serpentes: Typhlopidae). Systematics and Biodiversity 2:79-82 <link>

Lanza, B. 1990. Rediscovery of the Malagasy colubrid snake Alluaudina mocquardi Angel 1939. Tropical Zoology 3:219-223 <link>

Mulcahy, D. G., J. E. Martínez-Gómez, G. Aguirre-León, J. A. Cervantes-Pasqualli, and G. R. Zug. 2014. Rediscovery of an endemic vertebrate from the remote Islas Revillagigedo in the eastern Pacific Ocean: The Clarión Nightsnake lost and found. PLoS ONE 9:e97682 <link>

Mulcahy, D. G. and J. R. Macey. 2009. Vicariance and dispersal form a ring distribution in nightsnakes around the Gulf of California. Molecular Phylogenetics and Evolution 53:537-546 <link>

Murphy, J. C., T. Chan-Ard, S. Mekchai, M. Cota, and H. K. Voris. 2008. The rediscovery of Angel’s Stream Snake, Paratapinophis praemaxillaris Angel, 1929 (Reptilia: Serpentes: Natricidae). The Natural History Journal of Chulalongkorn University 8:169-183 <link>

Passos, P. and J. C. Arredondo. 2009. Rediscovery and redescription of the Andean earth-snake Atractus wagleri (Reptilia: Serpentes: Colubridae). Zootaxa 1969:59-68 <link>

Passos, P., D. F. Cisneros-Heredia, and D. Salazar-V. 2007. Rediscovery and redescription of the rare Andean snake Atractus modestus. The Herpetological Journal 17:1-6 <link>

Peters, J. A. 1960. The snakes of the subfamily Dipsadinae. Miscellaneous Publications of the Museum of Zoology, University of Michigan 114:1-228 <link>

Ramírez-Bautista, A., C. Berriozabal-Islas, R. Cruz-Elizalde, U. Hernández-Salinas, and L. Badillo-Saldaña. 2013. Rediscovery of the snake Chersodromus rubriventris (Squamata: Colubridae) in cloud forest of the Sierra Madre Oriental, México. Western North American Naturalist 73:392-398 <link>

Rasmussen, A. R. 1992. Rediscovery and redescription of Hydrophis bituberculatus Peters, 1872 (Serpentes: Hydrophidae). Herpetologica 48:85-97 <link>

Rasmussen, A. R., J. Elmberg, K. L. Sanders, and P. Gravlund. 2012. Rediscovery of the rare sea snake Hydrophis parviceps Smith 1935: identification and conservation status. Copeia 2012:276-282 <link>

Ray, J. M., C. E. Montgomery, H. K. Mahon, A. H. Savitzky, and K. R. Lips. 2012. Goo-eaters: Diets of the Neotropical snakes Dipsas and Sibon in central Panama. Copeia 2:197-202 <link>

Reyes-Velasco, J., C. I. Grünwald, J. M. Jones, and G. N. Weatherman. 2010. Rediscovery of the rare Autlán Long-tailed Rattlesnake, Crotalus lannomi. Herpetological Review 41:19-25 <link>

Rodríguez, M. J. R., E. J. Bentz, D. P. Scantlebury, R. R. John, D. P. Quinn, J. S. Parmerlee Jr, R. W. Henderson, and R. Powell. 2011. Rediscovery of the Grenada Bank endemic Typhlops tasymicris (Squamata: Typhlopidae). Journal of Herpetology 45:167-168 <link>

Savage, J. M. and R. W. McDiarmid. 1992. Rediscovery of the Central American colubrid snake, Sibon argus, with comments on related species from the region. Copeia 1992:421-432 <link>

Taylor, E. H. 1949. A preliminary account of the herpetology of the state of San Luis Potosí, Mexico. University of Kansas Science Bulletin 33:169-215 <link>

Wallach, V., V. Mercurio, and F. Andreone. 2007. Rediscovery of the enigmatic blind snake genus Xenotyphlops in northern Madagascar, with description of a new species (Serpentes: Typhlopidae). Zootaxa 1402:59-68 <link>

Weaver, R. E. 2010. Activity Patterns of the Desert Nightsnake (Hypsiglena chlorophaea). The Southwestern Naturalist 55:172-178 <link>

Life is Short, but Snakes are Long by Andrew M. Durso is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Spider-tailed Adders

Click here to read this post in Spanish!

Haga clic aquí para leer este blog en español!

This species was brought to my attention about two years ago by a friend who, like me, was working on completing her Master's thesis at that time. In the post-script of her message, titled 'Probably the coolest thing I've learned in weeks', she wrote "PS I swear this started out as a legitimate search for information for my thesis." In addition to being a welcome distraction from my writing, the story of the Spider-tailed Horned Viper, Pseudocerastes urarachnoides, is, in my opinion, one of the most interesting recent discoveries in herpetology.

The tail in question

The first specimen of P. urarachnoides was collected in 1968 by the Second Street Expedition, mounted on behalf of Chicago's Field Museum of Natural History by a retired businessman and activist couple, William and Janice Street. The primary purpose of the expedition was to collect mammal specimens, but reptiles were also collected, including the first specimen (also known as a type specimen or holotype) of P. urarachnoides. Because only a single specimen was collected, its unusual tail morphology was thought at first to be a solfugid clinging to the tail. Solfugids (also called solpugids, camel spiders, wind scorpions, or sun spiders) are members of the same arthropod class, the Arachnida, as spiders and scorpions, although they are neither spiders nor scorpions. Upon closer examination, the Field Museum's Steven Anderson found that the tail of the snake bore a peculiar structure with an uncanny resemblance to a solfugid that could have been a tumor, congenital defect, or growth caused by a parasite. The snake was identified as Pseudocerastes persicus, the Persian Horned Viper, and entered into the Field Museum collection, where it was almost, but not quite, forgotten.

Egyptian Giant Solfugid (Galeodes arabs)

The story ended there, until 2001, when Hamid Bostanchi collected a second specimen with identical tail morphology to the first. A third specimen was later discovered in the collection of the Poisonous Animal Section of the Razi Institute in Karaj, Iran, in 2008; it had been misidentified as a Desert Horned Viper, Cerastes cerastes. Together with Anderson, who had described the first specimen, and their colleagues Haji Gholi Kami of Gorgan University and Ted Papenfuss of the Berkeley Museum of Vertebrate Zoology, they described the new species in 2006, naming it Pseudocerastes urarachnoides, from the Greek ura (tail), arachno (spider) and ides (similar to). In their paper, Bostanchi et al. described the structure of the tail, which is formed of the last pair of subcaudal scales, much enlarged, and a single enlarged dorsal scale. The elongated components are modified lateral scales. X-rays taken by the team showed that the caudal vertebrae extend well into this structure and are not deformed or modified. Bostanchi et al. also speculated that the function of the modified tail might be to augment caudal luring behavior exhibited by many vipers. By mimicking a solfugid, birds or other would-be solfugid predators could be enticed to approach within the viper's striking distance.

Behavioral observations made in 2008 of a live P. urarachnoides captured in western Iran and maintained in captivity confirm these ideas. Closed-circuit video was used to record behavior, and the results published in the Russian Journal of Herpetology by Behzad Fathinia of Razi University and his colleagues. They observed the snake, a juvenile male that regurgitated a Crested Lark, using its caudal lure to attract sparrows and baby chickens that they introduced into its enclosure. When the birds approached and pecked the tail, the snake struck and envenomated the birds, a process taking less than one half second. A bird was also found in the stomach of the paratype specimen, further evidence that this species might feed heavily on birds in the wild with the aid of its spectacular caudal lure. The tail of P. urarachnoides probably represents the most elaborate morphological caudal ornamentation known in any snake, with the possible exception of the sound-producing rattles of rattlesnakes.

Within its restricted range in the mountainous terrain of western Iran, P. urarachnoides inhabits rock crevices in the gypsum formations that comprise its hilly, arid habitat. Adaptations of the genus Pseudocerastes to desert life include supralabials (upper lip scales) with a serrated lower margin and a groove to accommodate the lower lip, which provide complete closure of the mouth and prevent sand from entering. The nostrils also have a valvular prominence to the same effect. The other two species of Pseudocerastes, P. persicus and P. fieldi, share these characteristics. These two species are sometimes combined, although differences in venom chemistry and scalation, along with the fact that their ranges are separated by the Zagros Mountains, suggest that they are probably distinct species (and they are certainly distinct morphologically from P. urarachnoides). Both overlap in range with P. urarachnoides in places.

P. urarachnoides

Two other recent and noteworthy discoveries of Old World pitvipers are worth a mention. One, Protobothrops mangshanensis, is a large and beautiful pitviper discovered in 1990 in mountainous regions in southern Hunan and reputed to be the only non-cobra capable of spitting venom. The other, Atheris matildae, discovered in 2011, is a member of an especially popular genus in the pet trade (although this could be said of many of the most beautiful vipers). The exact type locality of A. matildae, in the southern highlands of Tanzania, was concealed in order to limit collection for the pet trade. In addition, a novel strategy is being tested: A. matildae is being bred at a facility in Tanzania and the first few dozen offspring are being given away to collectors in order to reduce the market for illegally collected specimens. Whether this strategy will succeed remains to be seen, but hopefully A. matildae can be saved from the same sad fate as the Lao Newt, Roti Island Snake-necked Turtle, Chinese Leopard Gecko, coelacanth, and other species that have been overcollected almost as soon as they were described.

Atheris matildae

Protobothrops mangshanensis

Check out another amazing new snake discovery at Greg Laden's blog: once thought to be a single deadly sea snake, Enhyrina schistosa is actually two!

Update 1/16/2015: Check out this video of a P. urarachnoides actually caudal luring and catching a bird!

ACKNOWLEDGMENTS

Thanks to Heather Heinz for bringing P. urarachnoides to my attention, and to photographers and videographers Michael Kern, Behzad Fathinia, Michael & Patricia Fogden, Omid Mozaffari, and Alireza Shahrdari.

REFERENCES

Bostanchi H, Anderson SC, Kami HG, Papenfuss TJ (2006) A new species of Pseudocerastes with elaborate tail ornamentation from western Iran (Squamata: Viperidae). Proceedings of the California Academy of Sciences 57:443-450 <link>

David P, Tong H (1997) Translations of recent descriptions of Chinese pitvipers of the Trimeresurus-complex (Serpentes, Viperidae), with a key to the complex in China and adjacent areas. Smithsonian Herpetological Information Service 112:1-31 <link>

Fathinia B, Anderson SC, Rastegar-Pouyani N, Jahani H, Mohamadi H (2009) Notes on the natural history of Pseudocerastes urarachnoides (Squamata: Viperidae). Russian Journal of Herpetology 16:134-138 <link>

Fathinia B, Rastegar-Pouyani N (2010) On the Species of Pseudocerastes (Ophidia: Viperidae) in Iran. Russian Journal of Herpetology 17:275-279 <link>

Menegon M, Davenport T, Howell K (2011) Description of a new and critically endangered species of Atheris (Serpentes: Viperidae) from the Southern Highlands of Tanzania, with an overview of the country’s tree viper fauna. Zootaxa 3120:43-54 <link>

Stuart BL, Rhodin AGJ, Grismer LL, Hansel T (2006) Scientific description can imperil species. Science 312:1137 <link>

Life is Short, but Snakes are Long by Andrew M. Durso is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.