Sunday, May 26, 2013

How many species of snakes and other squamates are there? Part 2. And, the bigger problem.

The on-line Reptile Database lists 8,734 species of reptiles (squamates, chelonians, crocodilians and tuataras) as of February 2008, five years later in February of 2013 it reports 9,766 species, an increase of 11.9%. Lizard species increased by 14.1% and snake species increased by 8.9% during the five year period. In May of 2011 a graph of the number of snakes described each year since 1758 was posted on this blog and became the fourth most viewed item on this site. Given that interest and my own I decided to take a second look at the issue, in part this was prompted by some recent publications.
Predictions are always tricky because they are based on certain assumptions, and more likely than not, at least some of those assumption are just wrong. Species concepts are changing what is considered a species today would have not been considered a species in 1950. But the change in thinking is for the better, species concepts are now based upon ancestry rather than just morpho-types.

An excellent example of one species name covering many is Brachyorrhos albus, (Moluccan short-tailed snake) a medium sized, fangless, terrestrial homalopsid of eastern Indonesia. What George A. Boulenger, in his Catalogue of Snakes in the British Museum, published 120 years ago, considered Brachyorrhos albus has actually turned out to be three distinct genera and more than nine distinct species. Note that it is more than nine species because there are several yet undescribed species that are known. While it might be best to think about these species as cryptic, only the snakes in the genus Brachyorrhos are cryptic – a group of island species, with each island or group of islands having one or more species that are very similar in appearance. The other two genera are also island species, but are present on large islands (Sumatra and New Guinea and its satellites). Even superficial examination of Calamophis and a soon to be described genus suggest they are morphologically distinct from Brachyorrhos and it is difficult to consider these cryptic in the sense that they don’t look like Brachyorrhos – at all. So, one genus considered monotypic until 2012 was really three genera containing 9+ species. Possibly, just an anomaly.
Representatives of three different genera of 
snakes that were considered a single species 
until 2012.  Middle species is Brachyorrhos 
rafrayi, and bottom is Calamophis
ruuddelangi. JCM

But, how many more anomalies are there? My suspicion is quite a few. Table 1 lists eight genera found to contain cryptic squamates species in the first half of 2013. Note, that Lemme et al. suggest there are at least six lineages within Geckolepis, so the number of undescribed species in this genus is not just a single species. Also, Graham Reynolds et al. (2013) resurrect the genus Chilabothrus for the West Indian members of the boid genus Epicrates and suggest there is an unrecognized species in one of the best known regions of the planet and in a family of snakes that has been particularly well studied in terms of its taxonomy. Also remarkable is the discovery that the Italian “slow worm” Anguis is quite distinct from Anguis fragilis, the species with which it has been long confused.

Table 1. Squamate genera containing species considered cryptic described in the first half of 2013.

Genus
Geography
Reference
Ameiva (Teiidae)
Brazil
Giugliano et al 2013
Anguis (Anguidae)
Italy
Václav et al. 2013
Atractus (Colubridae)
Brazil
Passos et al. 2013
Chilabothrus (Boidae)
West Indies
Graham Reynolds et al. 2013
Cyrtodactylus (Gekkonidae)
Thailand
Pauwels et al. 2013
Geckolepis (Gekkonidae)
Madagascar
Lemme et al. 2013
Helicops (Colubridae)
Brazil
Kawashita-Ribeiro et al. 2013
Stenocercus (Iguanidae)
Ecuador
Torres-Carvajal & Mafia-Endara, 2013

So, it is clear there are many species of squamate reptiles left to be described – all of the evidence says so. But there is a bigger problem – how many species of organisms are there and how rapidly are we causing them to become extinct?
In a 2011 paper by Camilo Mora of University of Hawaii at Manoa and colleagues presented a graph that suggests the number of reptiles (mostly squamates) left to be described  is about 30% of known species – producing a total number of squamates at about 12,615 (my math, not theirs). 

They could be correct – but the actual number of undescribed squamates will prove much greater: the reason – cryptic and fossorial species. Cryptic species seem abundant, overlooked, and disregarded while fossorial squamates are extremely difficult to access.  A Google Scholar search for the words “cryptic species” for the first five months of 2013 returns 4980 papers on virtually all groups of organisms. Restrict the search to “cryptic species reptiles” and the number of returns goes to 550 (~110 papers per month, or about 3.6 papers per day).

Mora et al. (2011) note the total number of species is based on the opinion of taxonomic experts, and note estimates range between 3 and 100 million species for life forms on Earth. They comment that these numbers likely represent the extremes of estimated species. There appears to be about 1.2 to 1.9 million names applied to species, Mora et al. use the lower number. Current description rates of eukaryote species in the last 20 years is about 6,200 species per year, the average number of new species described per taxonomist's career (~24.8 species), and the estimated average cost to describe a new species of animal is about US$48,500 per species (this seems exceptionally high to me but it works out to about $1.2 million/taxonomist during their career). They note that if these values remain constant and are similar among taxonomic groups, describing Earth's remaining species may take 1,200 years, would require 303,000 taxonomists, and cost about US$364 billion. 

Extinction rates now exceed natural background rates by a factor of 100 to 1,000 and raise the issue of species becoming extinct before we know they even exist. Using Mora et al.’s estimated number of 8.7 million eukaryotic species on the planet, and their estimate of about 1.2 million names, 13.8% of Earth’s life forms have been described. 

Now we come to a new view point, Costello et al. (2013) suggest there is no evidence that extinction rates are as high as some have feared, Nigel Stork (one of the authors was quoted as saying, "Surprisingly, few species have gone extinct, to our knowledge. Of course, there will have been some species which have disappeared without being recorded, but not many we think." Professor Stork said part of the problem is that there is an inflated sense of just how many animals exist and therefore how big the task is to record them. "Modern estimates of the number of eukaryotic species have ranged up to 100 million, but we have estimated that there are around 5 million species on the planet (plus or minus 3 million)." And, Stork claims there are more scientists than ever working on the task. This is contrary to the common belief that we are losing taxonomists, the scientists who identify species. He was quoted as saying, "While this is the case in the developed world where governments are reducing funding, in developing nations the number of taxonomists is actually on the rise.”

With the new number of estimated species set at five million, ±3 million we could be very close to having named all of the species. And, with the extinction rates low – clearly we have nothing to be concerned about. Right?

While the number of taxonomists may be on the rise in the Third World, so is the number of people on the planet – sometime during 2012 we exceeded 7 billion Homo sapiens who insist on grinding up one ecosystem after another to support our unsustainable population. The Costello paper has been criticized for its methodology of using well studied groups of organisms to make predictions about poorly studied groups, with one reviewer pointing out they are measuring human activity – not the number of species in nature.

The paper is unfortunate because it serves only to confuse the issues of biodiversity and extinction, and you really have to wonder what those guys were smoking!

References
Costello MJ, May RM, Stork NE. 2013. Can We Name Earth's Species Before They Go Extinct? Science, 2013; 339 (6118): 413 DOI: 10.1126/science.1230318

Giugliano LG, Nogueira C, Valdujo PH, Collevatti, RG, Colli GR 2013. Cryptic diversity in South American Teiinae (Squamata, Teiidae) lizards. Zoologica Scripta,  early online

Graham Reynolds, R, Niemiller ML, Hedges SB, Dornburg A, Puente-Rolón AR, Revell LJ, 2013. Molecular phylogeny and historical biogeography of West Indian boid snakes (Chilabothrus). Molecular Phylogenetics and Evolution, Available online 10 May 2013, ISSN 1055-7903, 10.1016/j.ympev.2013.04.029.

Kawashita-Ribeiro RA, Ávila RW, and Morais DH. 2013. A New Snake of the Genus Helicops Wagler, 1830 (Dipsadidae, Xenodontinae) from Brazil. Herpetologica 69: 80-90.

Lemme I, Erbacher M, Kaffenberger N, Vences M, Kohler J. 2013. Molecules and morphology suggest cryptic species diversity and overall complex taxonomy of fish scale geckos, genus Geckolepis. Organisms, Diversity & Evolution 13:87-95.

Mora C, Tittensor DP, Adl S, Simpson AGB, Worm B 2011. How Many Species Are There on Earth and in the Ocean? PLoS Biology 9(8): e1001127. doi:10.1371/journal.pbio.1001127

Passos P, Junior MTA,  Recoder RS, Sena MA de, Vechio FD, Pinto H B de A., Mendonça SHST, Cassimiro, J, & Rodrigues MT. 2013. A new species of Atractus (Serpentes: Dipsadidae) from Serra do Cipó, Espinhaço Range, Southeastern Brazil, with proposition of a new species group to the genus. Papéis Avulsos de Zoologia 53(6), 75-85. 

Pauwels, OSG, Sumontha M, Latinne A, Grismer L. 2013. Cyrtodactylus sanook (Squamata: Gekkonidae), a new cave-dwelling gecko from Chumphon Province, southern Thailand. Zootaxa 3635 (3): 275–285.

Torres-Carvajal O, Mafia-Endara P. 2013. A new cryptic species of Stenocercus (Squamata: Iguanidae) from the Andes of Ecuador. Journal of Herpetology 47:184-190


Václav G,  Benkovský N,  Crottini A, Bellati A, Moravec J, Romano A, Sacchi R, Jandzik D. 2013, An ancient lineage of slow worms, genus Anguis (Squamata: Anguidae), survived in the Italian Peninsula. Molecular Phylogenetics and Evolution, Available online 20 May 2013, ISSN 1055-7903, 10.1016/j.ympev.2013.05.004.

Monday, May 20, 2013

Nano scale structure contributes to Gaboon viper camouflage

Bitis rhinoceros, West African Gaboon viper (a) The snake partly on white
background and (b) partly on leafy substrate similar to the natural habitat.
The West African Gaboon viper is a highly effective ambush predator that becomes invisible in leaf litter due to the empty black patches of its skin that are virtually indistinguishable from shadows on the forest floor. In a new paper Spinner and colleagues (2013) examine the micro-ornamentation from shed skins from two Gaboon vipers, Bitis rhinoceros, and find its excellent camouflage is due not only to its overall coloration and pattern but to the microstructure of the scales. The viper's skin is geometrically patterned and features velvet black spots that have an exceptional spatial depth due to their velvety surface texture. The authors found a unique hierarchical pattern of leaf-like microstructures striated with nanoridges on the snake scales that coincides with the distribution of the black coloration. Velvet black areas have four times less reflectance and higher absorbance than other scales in the ultraviolet to near infra-red spectral range.

The authors suggest that the microornamentation in velvet black regions of the Gaboon viper skin is unique in snakes. Leaf-like microstructures with both nanoridges and hair-like nanoprotuberances that coincide with black skin coloration have not been previously described. Other members of the genus Bitis have less complex dorsal patterns of lower micro-scaled elevation with pits, a structure similar to that of the pale regions of Gaboon viper skin. When the research team coated the scales from the pale regions of skin with gold-palladium they took on a metallic appearance. But when the scales over the black patches were coated the color contrast remained because coated black areas remain black. Thus, the surface structures of the black scales was responsible for the velvet black appearance.

The entire article can be found on-line.

Spinner, Kovalev, Gorb & Westhoff. 2013. Snake velvet black: Hierarchical micro and nanostructure enhances dark colouration in Bitis rhinoceros. Scientific Reports. http://dx.doi.org/10.1038/srep01846

Friday, May 17, 2013

Bd originated in Xenopus laevis

An African Clawed Frog. These frogs, originally
imported to the U.S. for pregnancy tests, have now
established populations in the wild.
SAN FRANCISCO, May 15, 2013 --African frogs, originally imported for early 20th century pregnancy tests, carried a deadly amphibian disease to the U.S., according to a new study published today in the journal PLOS ONE.

African Clawed Frogs have long been suspected of introducing a harmful fungus called Batrachochytrium dendrobatidis or Bd to new populations that haven't been exposed to this pathogen before. The fungus has led to the recent decline or extinction of 200 frog species worldwide. A previous study found that the earliest case of Bd in the world was found in African Clawed Frogs in their native South Africa in 1934, but until now no research has tested for the disease among this species in populations that have become established in the U.S.

An African Clawed Frog. These frogs, originally imported to the U.S. for pregnancy tests, have now established populations in the wild.

"We found that African Clawed Frogs that have been introduced in California are carrying this harmful fungus," said SF State biologist Vance Vredenburg. "This is the first evidence of the disease among introduced feral populations in the U.S., and it suggests these frogs may be responsible for introducing a devastating, non-native disease to amphibians in the United States."

From the 1930s to 1950s, thousands of African Clawed Frogs were exported across the world for use in pregnancy tests, scientific research and the pet trade. These frogs will ovulate when injected with a pregnant woman's urine.

"Today, these frog populations are often found in or near urban areas, probably because hospitals released them into the wild when new pregnancy testing methods were invented in the 1960s," Vredenburg said.

Named for the claws they use to catch prey, these greenish-grey frogs live in pools and streams and have established feral populations in the U.S., including in San Francisco's Golden Gate Park.

African Clawed Frogs are potentially potent carriers of the Bd fungus because they can be infected for long periods of time without dying, allowing them to pass it on to more vulnerable species.

"It's amazing that more than half a century after being brought to California, these frogs are still here, and they still carry this highly infectious disease," said Vredenburg, associate professor of biology at SF State. "This implies that there must be a stable relationship between the pathogen and the frogs, whereas there are other frog species, for example in the Sierra Nevada, which have been wiped out by the pathogen."

For this latest study, Vredenburg and colleagues tested museum specimens at the California Academy of Sciences. They assessed the prevalence of the disease by swabbing DNA from the skin of preserved African Clawed Frog specimens that were collected from wild populations in California between 2001 and 2010.

They also tested archived specimens collected in Africa between 1871 and 2010 and found evidence confirming that Bd was present among indigenous populations of this species before they were exported worldwide.

Although no longer used in pregnancy testing, African Clawed Frogs are still imported to the U.S. for use in biomedical and basic science research. Because of their suspected role as a carrier of the Bd fungus and other potential pathogens, eleven states in the U.S. have already restricted the importation of these frogs, for example by requiring special permits and not allowing them to be sold as pets.

"Back in the 1960s, African Clawed Frogs were kind of ignored in terms of conservation research but now the damage has been done," Vredenburg said. "Now, we need to be cautious about other introduced species, including those in the pet and food trade. There could be other animals out there that are carrying diseases that we don't even know about yet."

"Prevalence of Batrachochytrium dendrobatidis in Xenopus Collected in Africa (1871-2000) and in California (2001-2010)" was published May 15, 2013 in PLOS ONE. Vredenburg co-authored the paper with Samuel V. G. McNally, a graduate student in Vredenburg's lab, and Stephen A. Felt, Erica C. Morgan, Sabrina Wilson, and Sherril L. Green from Stanford University.

The paper is available online at

Thursday, May 16, 2013

Suzio Report April 6


Howdy Herpers,                                                        

About 20 miles north of the center of Tucson lies a mountain range called the Tortolita Mountains. While the Tortolitas are rather vast in the area that they cover, they don’t exactly tower majestically above the flat landscape that surrounds them. At a distance, they are rather drab in appearance, mundane, not eye-catchers by any stretch of the imagination. I would venture that over half the people in Tucson, (the environmentally brain dead half), have never even noticed them, let alone know them by name.

Back in the early 1980s, this range was remote, and well outside the perimeter of civilization. When we wanted to get into the true wilds of Arizona, we’d drive down a two-track as far as we could along the southern edge, and then bushwhack in. We’d find lots of relics from the ancient ones. Arrow heads, pottery shards, petroglyphs. The Southern Tortolitas were a little known treasure, with steep, boulder infested hillsides that were in turn studded with dense Saguaro forests.

There is a road called Tangerine Road that flanks the southern edge of the range. This was a paved road even in the 80s, but traffic was near nil. It was a great road to cruise for herps. Back in 1983, I got my first glimpse of a wild Gila Monster on that road. Right where it makes the big bend, about a half kilometer from I-10. It was a DOR, but very fresh, with vibrant colors, and in pristine shape. I pried open its snappers, and marveled at the sharp, hooked teeth, and forked tongue. I was understandably excited with the find, and even picked it up off the road and put it in my vehicle. Off I drove with it lying on the floorboard on the passenger side of my Nissan. I was going to take it home to show my family and friends. But then, the laws being what they are, I freaked out, and took it back to where I found it. I lovingly placed it several paces off the road. I couldn’t bear to put it back on the road as found. It somehow seemed more dignified to have its final resting place under a creosote, than to leave it on the road as miniature speed bump.

In May of 1985, I was barreling down 1-10 with a buddy of mine. We were heading to the Chiricahua Mountains for a hike in the monument. About the time that we hit the Spanish Trail exit, I saw a Gila Monster traveling south across the freeway. It was just starting to cross the road. My poor hiking buddy will never understand what happened next, for John was not a herper. (In other words, he was “normal.” They’re all around us.)

I locked up the brakes, veered right, and managed to come to scorching stop about 100 meters past the point where the monster had been first spotted. Without a word, I swung open the door, (not bothering to close it), and wind-sprinted back through the smoldering black smoke that is synonymous with 20,000 miles of brake lining and tire rubber being erased from the respective life-expectancy of each.

These were the days when I could wind-sprint. I was lean, I was fast, I was strong­and MAN was I ever jacked up to catch that Gila Monster! I’ll never forget the jostling view of that monster entering the left lane as the ground evaporated beneath the rapidly rhythmic thudding of feet. By the time I pulled within 20 meters of the monster, despite the speed of my approach, and despite the determination and adrenaline flow, I began to see that this was going to end badly. Now the monster was on the centerline, with an 18 wheeler bearing down on it like there was no tomorrow. I cut in front of the semi, head on, and tried to wave him over into the left lane while I closed the final distance between the monster and I. The plan in my mind was clear. The trucker would see me gunning for the Gila Monster, and then being the “knight of the road” that truckers are reputed to be, he would yield to the oncoming geek charge. But Mr. Trucker had other ideas. His remedy for the situation was to lay on his air horn, whilst staying his course. When I was a scant five meters from the monster, and perhaps 20 meters from the oncoming semi, I saw the hopelessness of it all. As I sprinted in front of the barreling semi to get to the left lane and out of his way, I tossed a “deer-in-the headlights” look his way. The burly, bearded sunovabitch was not attempting to slow down. If anything, he was speeding up! The last look I had of him was at very close range. And I swear to God he was laughing! And then came the dwindling Doppler effect of the air horn roaring past, lessening in intensity as distance overcame sound, and the swirling road dust sand-blasting my being. Far worse than that was the sight of my second-ever wild Gila Monster plastered to the pavement like a bloody road Frisbee. Ten years of my life were lost in the bellicose cussing that followed. What an asshole!  

I moved to Tucson in 1981. In selecting a place to settle down, finding a wild Gila Monster weighed in as a heavy factor in the relocation process. In 1983, the dead one on Tangerine Road came my way. Then, in 1985, it was literally “east bound and down” with the second. It was not until April of 1989 that I saw my next wild Gila Monster. And FINALLY that one was alive. I went 7 years and 11 months to consummate my dream of seeing a living Gila Monster in the wild.

Tangerine Road is no longer a quaint little paved road suitable for road cruising. It is now mostly a 15 mile stretch of four lane super highway. There are still a few patches of wild Sonoran Desert flanking it, but that ain’t much. And that is surely going to fall soon. Many developments such as Dove Mountain, Stone Canyon, and too many others to enumerate here have engulfed the best of what the southern Tortolitas used to be. Tiger Woods swings his driver where we used to herp.

But the north side of the range is still good. And it was here, in a vast canyon that some of us know as April Canyon, that I saw my first wild Gila Monster. The story of this find is a long one, so I will save it. Said story has already been documented. It can be found on the Tucson Herpetological Society website. Go for “Publications,” “Collected Papers,” and find page 163.

The experience of seeing that first wild Gila Monster was one of reverence for this herper. It is only natural that I would hold the ground on which it was found with the same regard. Once a year, I go back to April Canyon. Twenty-four years later, it still remains largely unchanged from the day I saw my first Gila.

This year, it was on 6 April 2013 that I revisited my Heloderma Alma Mata. Marty Feldner, Karla Moeller, Megan Morgan and I met at 0805 that morning. We were supposed to meet at 0800, but Marty was late by 5 minutes. As there was no sense whatsoever in being prompt if Marty was going to be late, I arrived just after he did. There was more than the usual flandickery in preparing to drive to our final destination. Marty had scooped a young male DOR Mojave Rattlesnake off the road enroute in, and no small amount of time was spent fondling and admiring that. Then, in order to make room for everybody, I had to unload 20 tons of camping gear into Karla’s war wagon. But all that was eventually behind us. Chivalry died back in the 90s, when women started to demand equal rights. Hence, we put the women in the back of the bus, Marty promptly settled into the shotgun seat, and I took the wheel of my White Knight. Bap! We were heading eastward to April Canyon.

There was a brief moment of excitement when Marty spotted an average-sized male diamondback rattlesnake on the right side of the quad trail that we were negotiating. The White Night regurgitated its vehicular contents, and we all encircled the snake to commune with him for a few minutes. We left him none the worse for the wear, and he was no doubt happy to see us go.

We arrived at April Canyon at precisely 0900. The air temp was 22C, it was cloudless. My trusty Kestrel indicated there was 20% humidity, and a 0-3 mile-per-hour breeze. We were at 3400 feet in elevation. I’m the only one of the group who knows these things, as I was the only one to take the time to document it all. The other three left me behind like a soiled hanky while I did so.

I showed Karla this place because she needs to fully process ten different adult Gila Monsters in April, and ten again in June. April Canyon is a place where that is possible. To reveal any more of the purpose for being there is not ethical. Karla’s work needs to be done in a quiet manner. It is hoped that we will learn something about the physiological effects of drought on Gila Monsters. If in the process, we free Tibet, we won’t complain. And my purpose for being there was to see herps. Any Gila Monsters would be a bonus.

By the time I had finished all the documentation, my three companions were out of sight. At this point, April Canyon is a wide open sandy wash that narrows as one ascends up canyon. Both sides of the canyon are flanked with lush desert vegetation. The mesquites grow tall and mighty here, and dense thickets of hackberry and nasty catclaw abound. I was able to see where the group did not walk, and started my route up in that direction. I immediately found an adult female diamondback stretched out in the sand, heading across the wash in westerly fashion. I tried snapping some undisturbed images, but she drew into a semi-defensive posture, and began pedaling away from me, with head held high and rattles singing. About the time this one was found, Marty found another. His was a male.

At 0925, I caught up with the group. They were all huddled together in wash center. They had found their first Gila Monster. It was an adult female that Marty had found in the center of the wash. She was found with snout in the sand, and had been digging. She was processed and released to get on with her life. Shortly after this experience, Megan was pointing to something chest high in the trees and murmuring in her soft voice. This eventually brought us all to her side.

Thrust upon a horizontal branch of a mesquite tree was the head and neck of a diamondback rattlesnake. A CRAT-sickle! It was fairly fresh, as the eyes were still in the sockets, and the black tongue still dangled out of its gaping mouth. It served as grotesque  reminder that all who enter April Canyon are not nature lovers. It is this kind of crap that causes us to hate so many people who abuse the sanctity of our wild places. We grow ever-tired of the ignorance of those who invade nature under the guise of appreciating her, only to be offended when she comes calling. (Or, in this case, “comes crawling”). It is impossible to fathom the blatant and consistent lack of respect for living organisms that is shown for some of our wildlife. What assholes!

The next round of excitement occurred when Marty spotted a mid-sized gophersnake sprawled lengthwise at the west edge of the wash. At first, the snake remained motionless, and we tried to move in for some pictures. Then, it began slithering slowly eastward across the wash in front of us. Megan had fallen behind us in the search effort, so we called her up for a look. Karla was on the slope above us, to the east of the action. She asked of us if it was worth her coming down to view the snake, and we replied that it was nothing spectacular. It was just shy of a meter long, just a scrawny “nuthin’ special” sort of gophersnake. (How dare I say that a gophersnake is “nothin’ special!” They’re all special, but not when the focus is on other things. Were it a five-foot long hefty beauty, Karla would have been severely berated if she even hesitated to come down for a look). Moments later, the nuthin’ special snake slid into some overhanging roots of a mesquite on the east berm of the wash. It was at this point that nuthin’ special morphed into “sumthin’ special,” for within the framework of those mesquite roots was a Gila Monster!

“NOW you need to come down, Karla!”

We waited patiently before moving in to process this second monster, in hopes that maybe the gophersnake would attempt to interact with it. But by this time, both animals were aware of our presence, spooked to the max, and there was to be no excitement save for that of having two cool species of herp occupy the same patch of ground. The gophersnake was left to get on with its life. The Gila Monster did not get off quite that easily, but the processing went smoothly. This one was a dandy of a male. His mass was 591 grams, and he was 553mm (21.77 inches) in total length. Certainly not a record length or mass by any means, but he was a healthy monster by Sonoran Desert standards.

Earlier in this narrative, the first glimmers of Gila Monsters in my life were mentioned. By the time that first April Canyon Gila Monster was discovered, I had a friendly association with one of the early monster masters in our region. We speak of Brent Martin. By the late 1980s, Brent claimed that he had found over 200 of them. He was also quick to point out that this impressive total was accumulated through decades of seeking them. While I believed Brent, that number of 200 seemed astronomical. It was a record that I could never even approach. A careful search of my records indicates that our nuthin’ special gophersnake led us to wild Gila Monster number 305. The simple number of 305 just doesn’t look right when spelled out numerically. That ain’t saying it proper. Let’s put that number in writing. THREE HUNDRED FIVE Gila Monsters! Yeah, baby! And there wasn’t even a ticker-tape parade to honor the event……..

We left number 3-oh-5 to get on with his life. And the search for number 306 was on. It was ascertained that it was time to head back down the canyon. A short while later, Marty sounded off, “Monster!” This one was found sprawled in a dense thicket of catclaw, on the east berm of the wash. It was a vividly-colored juvenile, which unfortunately was of no use to Karla. However, as a DNA sample, it was useful to those who Marty and I serve. Mother Repp never raised a child so foolish as to plunge into a catclaw thicket after a monster that he didn’t even find. Marty found the darn thing, let him be the hero! Yeah! Let Marty do it! Go get her, boy! By the time Marty had her, the harsh shrubbery was gaily festooned with strips of Marty bacon. Let that be a lesson to the lad about finding things among pernicious plant parts……….

This monster turned out to be a female, we would estimate entering the fourth year of her sweet young life. We all took turns taking pictures, and Karla drew a little blood for the DeNardo lab. Once we were done having our way with her, we simply let her go to see what she would do. What she did proved to be the highlight of the day. At the point where we turned her loose, she was roughly 20 meters up wash from her capture spot. Rather than heading in that direction, she bolted for the cover on the east berm. She approached a burly, vertical scaly trunk of a massive mesquite, and began deftly crawling up it. She stopped her ascent when she was about two meters above the ground. She was a sitting duck for the photographs that followed.

This is only the second time that I have witnessed a monster go arboreal. This puny N of 2 not only takes into consideration the 306 different wild Gila Monsters observed over the past 25 years, but also includes well over a thousand observations on telemetered animals as well. The first time we witnessed this happening was with our telemetered Gila Monster #15. He earned the name “Tarzan” as a result of his climb. In both cases, there is evidence that escape from human interlopers was the possible motive. And just recently, Marty has sent along an image of a third monster that he saw start up a mesquite, again possibly to avoid capture. Unlike their cousins the Beaded Lizards, which are avid tree climbers, it appears that this behavior is only rarely encountered with Gila Monsters.

Getting back to 6 April, whilst going off on a paragraph of bygone days, we left our juvy Gila clinging tenaciously two meters above ground on the trunk of a mesquite tree. There was some discussion amongst the fab four about leaving her there like so much painted fruit. But our desire to feed the local raptors was minimal, and she was snatched from her moorings and released into the briar patch from whence she came. It is hoped that she was able to snack on some of the Marty bacon that was so generously hung for her.

It was 12:30 when we got back to the White Knight. I was a half hour late for my first beer of the day. Those who bottle Dos Equis were on high alert, and the workers were fearful of lengthy furloughs. The world’s most interesting man grew boring, developed a stutter, and began picking his nose in public. On a more personal note, by the time I got the cap off the bottle, little pink elephants were swirling about, and closing in on me in a most menacing manner. Disaster was narrowly avoided here.

Speaking of disasters, lunch came next. Marty and I are not accustomed to the field fare that the folk in DeNardo’s lab subsist upon. Instead of steak and lobster, these kids serve blobs of brown and red sticky substances slathered on wonder bread. And they think they are walking in tall cotton by doing so. The temptation to hike back for some strips of Marty bacon was strong, and we began eyeing the maggots in the abundant drying cowpies as potential side dishes. This is what you get when you let KIDS lead the charge! When left to our own devices, every meal is a banquet. The next time we are in Rome, we will not do as the Romans do!        

By 2 PM, we were just sitting around looking at each other. Marty began to talk about eating people. Cannibalism is a favored topic of his, especially when he is feeling malnourished. I expect Marty to talk about eating people when he is hungry, so there was no problem thus far. When the ladies wholeheartedly joined in Marty’s conversation, things got a little scary. Talk of cannibalism often results when the troops in the field are underfed and bored. The idle mind is the devil’s workshop, and it was time to think of something to do. (Lest one of us wind up in the cooking pot). My suggestion that we take a road cruise to 96 Hills in order to just keep moving was met with universal acceptance. Marty and I are old hands at counting lizards, and there were plenty to count on this hot spring afternoon. Soon, the boredom overtook the ladies, and they joined right in there to help.

“There are 2, no 3, no 4, 5-6-7, 9! 12! 14!” We were all singing out from all sides of the White Knight. Every 50 feet or so, we would jump the Zebra-tailed Lizards. When all was said and done with our otherwise pointless road cruise, we had racked up 237 of them! We also scored 10 Side-blotched Lizards, 4 Clark’s Spiny Lizards, 5 Desert Spiny Lizards, 18 Greater Earless Lizards, 6 Whiptails, 3 Tree Lizards, and 2 Leopard Lizards. The capper of the drive occurred at 1610 in the afternoon. I saw a smallish lizard waddle off to the side of the road into some tall grass. I stopped the vehicle, and was all sorts of insistent that we had just seen a Regal Horned Lizard. Others protested this not to be true.  I resisted the urge to get aggressive in my assertions, as I really wasn’t that sure. But we kept looking anyhow, and sure enough, Karla fished the horny toad out of the shrubbery. The crowd went wild! By the time that dusk rolled around, and the lizard activity stopped, we had racked up 289 lizards, with ten different species represented. That ought to help with my lizard count for the year of 2013. The numbers of Zebra-tailed lizards have been rather lackluster of late. It was one hell of a lizard day!

Just after the horned lizard, there was some universal lamenting about the lack of snakes on this road cruise. Just as soon as the grousing started, as if on queue, a meter long all black Coachwhip was observed in the center of the dusty road. It was one very jacked up snake. The ground-hugging greased lightning zipped to the side of the road, and evaporated, leaving a little black vapor trail in its wake. Despite further effort, that was to be the last good find of the day.

In closing this epic journey about a good herping day, perhaps a reminder to those of us who are blessed to live in Arizona is in order. We live in a place that epitomizes freedom. We can roam at will through a variety of habitats that range from sand dunes to above timberline. We should never take our public lands for granted, for it is these places that allow escape from the rat race of daily living. We can travel dirt roads, find a hill to climb, stand alone, and take back something worth remembering. And best of all, we live in a place where at any given moment, a gaudy orange and black hefty lizard can lumber across our path, and make our day.

This here is Roger Repp, signing off from Southern Arizona, where the turtles are strong, the snakes are handsome, and the lizards are all above average.

Images: The images that fall below were carefully arranged to follow the flow of this fabulous day. See text above for explanations. Images by Roger Repp and Marty Feldner.



Monday, May 13, 2013

Cannibalistic Tadpoles

The face of an unfortunate Budgett's frog tadpole
that is being digested inside the stomach of its larger
sibling.

A carnivorous, cannibalistic tadpole may play a role in understanding the evolution and development of digestive organs, according to research from North Carolina State University. These findings may also shed light on universal rules of organ development that could lead to better diagnosis and prevention of intestinal birth defects.

NC State developmental biologist Nanette Nascone-Yoder, graduate student Stephanie Bloom and postdoc Cris Ledon-Rettig looked at Xenopus laevis (African clawed frog) and Lepidobatrachus laevis (Budgett’s frog) tadpoles. These frog species differ in diet and last shared a common ancestor about 110 million years ago. Like most tadpoles, Xenopus exist primarily on a diet of algae, and their long, simple digestive tracts are not able to process insects or proteins until they become adult frogs. Budgett’s is an aggressive species of frog which is carnivorous – and cannibalistic – in the tadpole stage.

Nascone-Yoder knew that Budgett’s tadpoles had evolved shorter, more complex guts to digest protein much earlier in their development. She and her team exposed Xenopus embryos to molecules that inactivated a variety of genes to see if any might coax Xenopus to develop a more carnivore-like digestive tract. Remarkably, five molecules caused Xenopus tadpoles to develop guts that were closer in appearance to those of the Budgett’s tadpoles. Taking it one step further, Nascone-Yoder exposed Budgett’s frog embryos to molecules with opposite effects, and got tadpole guts that were closer to those of Xenopus.

“Essentially, these molecules are allowing us to tease apart the processes that play a key role in gut development,” Nascone-Yoder says. “Understanding how and why the gut develops different shapes and lengths to adapt to different diets and environments during evolution gives us insight into what types of processes can be altered in the context of human birth defects, another scenario in which the gut also changes its shape and function.”

The researchers’ next steps include finding out whether the changes in these gut tubes were merely cosmetic, or if they also function (digest) differently.

Citation
Bloom S,  Ledon-Rettig C, Infante C,  Everly A,   Hanken J, Nascone-Yoder N. (2013) Developmental origins of a novel gut morphology in frogs. Evolution & Development,  15 (3): 213 DOI: 10.1111/ede.12035

Friday, May 10, 2013

The Value of Unexpected Creatures


Recently I did a snake workshop for people who knew little about snakes, but were otherwise very well educated in various fields of endeavor (law, medicine, psychology). While discussing gliding snakes, one participant commented to the effect that we now have to worry about flying snakes. The comment was a reminder that the general public, even the well educated general public, lacks an appreciation for biodiversity.

[To the right: Wallace painted this watercolor of Rhacophorus 
nigropalmatus in 1855. At the time this was an undescribed species. Wallace wrote on the back of the watercolor the frog “descended from a high tree as if flying.” © ALFRED RUSSEL
WALLACE MEMORIAL FUND]

Appreciation for biodiversity is a core attitude for halting or at least slowing the current extinction event that we are experiencing. A society that understands ecology, evolution and biodiversity - natural history - is less inclined to be deluded by the idea that humans are in charge of the planet, and can act independently from nature and the ecosystem.

Unexpected creature can form the basis for the teachable moment. The moment that a person realizes there is more to the world that the societal myths that keep the masses occupied.  Yandell (2013) commented on the recent discovery of Alfred Russel Wallace's watercolor of the giant flying frog (Rhacophorus nigropalmatus). Wallace did the painting in 1855 shortly after a local Malaysian collected the frog and presented it to Wallace. The watercolor was used to produce the woodcut print in his 1869 book The Malay Archipelago.

Flying frogs and snakes are out of the ordinary, gliding and parachuting behavior is not something expected of amphibians and reptiles. Venomous squamates are also high interest herps that can attract the attention of the modern technological zombie. But there are many other unexpected species that can spark interest in the natural world. The giant Chinese salamander, Andrias davidianus, a completely aquatic, giant amphibian that reaches 1.8 meters in length. The tentacled snake, Erpeton tentaculatus, with a pair of rostral appendages making it the most distinctive serpent on the planet And, the mata mata turtle, Chelus fimbriatus, a bizarre highly aquatic turtle that creates a  vacuum to capture prey.

Whatever your favorite unexpected creature happens to be consider using it to introduce someone else to the world they live in.

Citation
Yandell, K. 2013. Flying Frog, 1855. The Scientist.

Thursday, May 9, 2013

Rana iberica's hidden life underground


Do frogs live underground? The answer is yes, some amphibians, such as salamanders and frogs have been often reported to dwell in subterranean habitats, some of them completely adjusted to the life in darkness, and others just spending a phase of their life cycle in an underground shelter. Up until 2010, however, no one suspected that the Mediterranean frog Rana iberica - commonly known as Iberian brown frog and usually found in streams - also participates in underground adventures. A new study published in the open access journal Subterranean Biology confirms the first report of Rana iberica reproduction in a cave-like habitat, with all life stages observed in the galleries.

Serra da Estrela Natural Park is located in north-central Portugal and is the largest protected area and one of the most biodiverse regions in Portugal and the Iberian Peninsula. Several drainage galleries were created for water capture in the 1950s, even before the establishment of the boundaries of the Natural Park. It is namely in these artificial subterranean habitats that the Iberian brown frog was discovered dwelling underground by biologists.

"The unusual sighting of R. iberica motivated a series of subsequent visits that started in 2011 up until December 2012 to understand the use of this artificial subterranean habitat by this species.", explains the lead author of the study Dr. Gonçalo M. Rosa. "All life stages were observed in the gallery during the study period, particularly adults, which were observed every month of the year."

The Iberian brown frog does not only seek refuge in the drainage galleries as a sporadic visitor. During long observations, adults from the species have been noted in the galleries,often standing on the ground or in crevices, swimming underwater or even climbing up the walls. There is evidence of mating activity, and batches of eggs have been found stuck to submerged rocks in the subterranean stream. Recently hatched tadpoles were also observed, initially remaining stationary above the egg mass for about two weeks, then swimming in the streams and feeding on the dead egg mass. The galleries are used by other amphibians as well, and larvae of the fire salamander Salamandra salamandra gallaica have been recorded twice while preying on brown frog tadpoles.

The choice of the artificial drainage gallery for a habitat of the Iberian brown frog may appear odd initially. However, it seems that the animals find a refuge in the cool and humid tunnels, often containing a small stream. These artificial subterranean habitats are in fact often used as a refuge for many species. They are, for example, particularly important for the salamander Chioglossa lusitanica, an Iberian endemic of conservation concern. Scientists express their fear that such preferences for underground habitats might in fact be a sign for the ecological dangers of the dramatic climate changes experienced by the Iberian region. Monitoring the subterranean activity of various species might provide important cues for future conservation efforts. The entire article is available on-line.

Rosa GM, Penado A (2013) Rana iberica (Boulenger, 1879) goes underground: subterranean habitat usage and new insights on natural history. Subterranean Biology 11: 15–29, doi: 10.3897/subtbiol.11.5170

Wednesday, May 8, 2013

Midwest frogs & mammal populations altered by invasive plant



Western Chorus Frogs in amplexus. JCM
The following is a press release from Lincoln Park Zoo.

Researchers at Lincoln Park Zoo and Northern Illinois University have discovered a new culprit contributing to amphibian decline and altered mammal distribution throughout the Midwest region – the invasive plant European buckthorn. This non-native shrub,  which has invaded two-thirds of the United States, has long been known to negatively impact plant community composition and forest structure, but these two innovative studies slated to publish in upcoming editions of the Journal of Herpetology and Natural Areas Journal demonstrate how this shrub negatively impacts native amphibians and affects habitat use by mammals including increased prevalence of coyotes and other carnivores.

Amphibians are facing an extinction crisis worldwide, with 165 species likely having gone extinct in recent years according to the Amphibian Ark, a coalition of conservationists devoted to seeking solutions to the decline. Lincoln Park Zoo Reintroduction Biologist Allison SacerdoteVelat, Ph.D. and Northern Illinois University Professor of Biological Sciences Richard King have identified European buckthorn as a contributor to amphibian decline in the Chicagoland area. The plant releases the chemical compound emodin, which is produced in the leaves, fruit, bark and roots of the plant, into the amphibian breeding pond environment at various times of year. Sacerdote-Velat and King’s research has found that emodin is toxic to amphibian embryos, disrupting their development, preventing hatching.

"Levels of emodin in the environment are greatest at leaf out, which is occurring right now in early spring. This coincides with breeding activity of several early-breeding Midwestern amphibian species including western chorus frogs and blue-spotted salamanders," explained Sacerdote-Velat. "Several amphibian species exhibit low hatching rates in sites that are heavily infested with European buckthorn."The Chicago Wilderness 2004 Woodland Audit found that in the Chicagoland area alone, more  than 26 million stems of European buckthorn exist with a density of 558 stems per acre. Whilst this study specifically found emodin to detrimentally impact development of two species of frogs, Western chorus frogs and African clawed frog (a common test species for environmental toxicity studies), Sacerdote-Velat and King hypothesize that emodin may impact the reproductive success of other frog species in regions where buckthorn is not native.

“Western chorus frogs are quite common in the Midwest, and people in Illinois who have never seen them have probably heard them in the springtime,” said King, who has continued to conduct research with Sacerdote-Velat after having served as her Ph.D. adviser at NIU. “The new study demonstrates how a shrub that is viewed by many as a decorative plant can become invasive and have unexpected and damaging effects on natural ecosystems.”

Additionally, new research from the zoo’s Urban Wildlife Institute reveals how the presence of the invasive shrub in forest preserves and natural areas correlates to increased prevalence of carnivores. Previous research by Ken Schmidt of Texas Tech University and Chris Whelan of Illinois Natural History Survey documented that these carnivores can prey more easily on native bird eggs and nestlings such as robins when nests are built in buckthorn and honeysuckle compared to nests built in native shrubs or trees.

“The relationship between invasive plants and wildlife is complex. This is the first study of its kind to investigate the association between buckthorn and habitat use by mammal species,” explained Director of the Urban Wildlife Institute Seth Magle, Ph.D. “We know based on prior research that birds which build nests in buckthorn are more susceptible to predation. Our study found that the presence of buckthorn alters wildlife distribution and attracts some carnivore species. We now know that there are significantly more coyotes, raccoons and opossums in buckthorn invaded areas, and significantly fewer white-tailed deer.”

Magle hypothesizes that the carnivores could be drawn to buckthorn areas because birds and their nests are easier to prey upon. He suggests that deer may be avoiding these areas because buckthorn is an undesirable food source, and also due to the increased prevalence of coyotes. Research shows that deer fawns are a relatively common food item for Chicago-area coyotes. Both Magle and Sacerdote-Velat agree that these findings are significant. The studies demonstrate how the high-density prevalence of this non-native plant is shifting population dynamics and negatively impacting a variety of native animal populations. They suggest land owners and managers should consider invasive species management and habitat restoration. In
some areas, like Lake County Forest Preserve District where Sacerdote-Velat works regularly,
ecologists and land managers have been committed to removing buckthorn from the area. "I hope that this new research will encourage other regions and land managers to take swift and decisive action to work to remove this invasive plant," she said.