Monday, December 31, 2012

Suizo Report -- Some Summer and Fall Highlights


Happy New Year Herpers,

I'm going to take a minute to try to persuade some of you to step up for the Tucson Herpetological Society. If any of you have a herp-related presentation of any sort that you would like to give us, please let me know. Currently, we have openings from March 2013 through infinity. We normally offer an honorarium, a free year membership, and a T-shirt or hat.

So, if some of you out of town folk are going to be coming this way any how, please try to time your visits for the third Tuesday of any given month. We likely can't afford travel expenses from far off places, but if you're planning to come to town anyway, why not?

Thanks!

My duties with the THS have made it difficult to send out these reports with any kind of regularity. Many cool things happened this year that I didn't get the chance to share with you all. Now I'm taking the time to make it so.

Image 1: Male Crotalus tigris #10, Jeff, 29 July 2012. I'm showing you this image because I think of it as a "classic" color phase for a tiger. Get a load of the next one.
Image 2, by Steve Ressel: What I call the "Silver Phase Tiger" From Sabino Canyon, 18 July 2012. Sweet!
Image 3: Quoting Dennis Caldwell, as he is aiming his camera at something in the Huachuca Mountains. "I got this fat tree lizard on a rock here--and oh, oh, I think she's about to $hit---Oh--and she did!" 8-)
Image 4: The same day that the tree lizard crapped, (22 July 2012), we found a gorgeous short horned lizard.
Image 5: Still the same trip, a DANDY Madrean Alligator Lizard (posed).
Image 6: John Slone and Marty Feldner led us to a land we dare not speak of to show us many wonders. This sweet little Crotalus cerberus was one such wonder.
Image 7: A Grand Canyon Rattlesnake, from John and Marty land. If I told you where it was, they would have to kill all of us.
Image 8: A Wandering Gartersnake, near the north rim of the Grand Canyon.

Image 9: In late August, the Chicago Herp Society was kind enough to fly me out for a presentation. They were also kind enough to take me herping in Carl Koch-land in Southern Wisconsin. They were NOT kind enough to let me find anything, but at least Gery was able to locate the purpose of the trip-- a  hog-nosed snake. This is a very young snake.
Image 10: Our biggest male Crotalus molossus, CM12. 29 September 2012
Image 11: This is the last image that I will ever get of female Crotalus atrox #121, Tracy. While the image is grainy, it clearly depicts how well these things can blend with their surroundings. But in Tracy's case, not good enough! We found her transmitter on the ground a week later. Bummer!
Image 12: My interest with Iron Mine Hill/Suizo Mountains began with lyresnakes. The crevice that this snake is in contained the third-ever lyresnake found there. It was used regularly from 1993-1995, and then only sporadically after. This image was taken on 22 December 2012--a week ago. I'm hoping to see more of this snake in the days and years ahead.
Image 13: What would a Suizo Report be without our beloved fat head "Gus." Here he is in situ on 22 December 2012.
I'm off to join the Suizo gang tomorrow. My last visit was on 22 December, and things are looking up. We've received close to 2 inches of rain the past two weeks. The annuals are starting to pop out of the ground. Three Gila Monsters can now be seen routinely, and we now have two active lyresnake crevices--one of which contains two snakes. Usually, when a few lyresnakes bask for us, several others will as well. We have three tiger rattlesnakes that can be seen regularly, as well as several atrox and a couple tortoises.

Things are looking up!

Here's hoping that our paths will cross again in 2013. Until that time, happy herping!

Best, roger
others do as well. 

Saturday, December 29, 2012

The White-flanked Malagasy Tree Frog, A New Frog from southern Madagascar

Guibemantis tasifotsy

Mantellid frogs comprises the largest radiation of frogs in Madagascar with 200 know species in 12 genera. Within the family, at least three clades have independently adapted to phytotelmic breeding: Blommersia angolafa, Mantella laevigata, and the subgenus Pandanusicola in the genus Guibemantis. Pandanusicola are small frogs with snout–vent lengths between 20–38 mm that typically reproduce in the leaf axils of Pandanus screw pines: their eggs are deposited on leaves near the water-filled axials, and the exotrophic tadpoles develop within these leaf axial pools. This breeding mode applies to all but one species, Guibemantis liber, which deposits its eggs on leaves overhanging ponds and swamps in which its tadpoles develop. Molecular data suggests a high proportion of undescribed species diversity in Guibemantis, and two recently described  lineages were described as new species in 2011. At present, there are eight nominal species included in the subgenus Pandanusicola. The identity and delimitation of most of these species is well understood; however, G. bicalcaratus, G. liber, and G. pulcher still require revision.

One possible species characterized by a strong molecular divergence to other Pandanusicola, is morphologically intermediate between G. liber and G. pulcher. Surprisingly, this species was collected while calling on vegetation over swamps, suggesting it was not using leaf axials as a mode of reproduction as in G. liber Although the molecular data did not indicate close relationships to this species.

Evidence from morphology, bioacoustics, and mitochondrial genes suggest the species is distinctly different from G. liber as well as from G. pulcher, and consequently Lehtinen et al. (2012) describe it as new species, the White-flanked Malagasy Tree Frog, Guibemantis tasifotsy. The new frog is known only from southeastern Madagascar and differs from most Pandanusicola by probably not breeding in leaf axials of Pandanus  but instead probably lays its eggs in open lowland swamps. Newly determined DNA sequences of the cytochrome b gene confirm that G. tasifotsy is genetically highly divergent from all other species of Guibemantis.

Citation
Richard M. Lehtinen, Frank Glaw, Franco Andreone, Maciej Pabijan, and Miguel Vences. 2012. A New Species of Putatively Pond Breeding Frog of the Genus Guibemantis from Southeastern Madagascar. Copeia 2012(4):648-662.

Thursday, December 20, 2012

Squamates & the Cretaceous Extinction

The carnivorous lizard Palaeosaniwa stalks a pair of hatchling Edmontosaurus as
 the snake Cerberophis and the lizard Obamadon look on. Obamadon gracilis is
a small polyglyphanodontian named after President Obama. These squamates 
disappeared with the dinosaurs at the Cretaceous extinction.

More than 9,000 living species of snakes and lizards exploit an extraordinary range of ecological niches and habitats. The history of this radiation extends deep into the Mesozoic. After the appearance of crown squamates in the Jurassic, lizards and snakes underwent a Cretaceous radiation, and by the late Cretaceous most major groups had appeared, including iguanians, geckos, skinks, anguids, and platynotans, as well as many lineages of  snakes. The Cretaceous–Paleogene (K-Pg) extinction that ended the Mesozoic and the dinosaurs is considered to have had little effect on squamate evolution with the exception of the marine mosasaurs. And, all major squamate lineages are thought to have survived the end of the Cretaceous. Now a new study by Longrich et al. (2012) suggests otherwise.

A revision of fossil squamates from the Maastrichtian and Paleocene of North America shows that lizards and snakes suffered a devastating mass extinction coinciding with the Chicxulub asteroid impact. Species-level extinction was 83%, and the K-Pg event resulted in the elimination of many groups of lizard groups and a dramatic decrease in morphological disparity. Survival was associated with small body size and perhaps large geographic range. The recovery was longed with diversity not approach Cretaceous levels for 10 million years after the extinction, and it resulted in a dramatic change in faunal composition. 

Citation
Nicholas R. Longrich, Bhart-Anjan S. Bhullar, and Jacques A. Gauthier. 2012. Mass extinction of lizards and snakes at the Cretaceous–Paleogene boundary PNAS 2012 ; published ahead of print December 10, 2012, doi:10.1073/pnas.1211526110

The First Known Freshwater Mosasauroid

An artist's drawing of the Pannoniasaurus inexpectatus 
that lived 84 million years ago in freshwater floodplains.
 (Image: Tibor Pecsics)
Until now, mosasauroids have been considered exclusively marine. However, László Makádi from the Hungarian Natural History Museum, and colleagues from the University of Alberta, Canada and MTA-ELTE Lendület Dinosaur Research Group, in Hungary report the discovery and describe Pannoniasaurus a new species having unsuspected adaptations to freshwater ecosystems.

The new mosasaur discovered in Hungary is the first known example of this group of squamate reptiles to have lived in freshwater river environments similar to modern freshwater dolphins.

The species lived about 84 million years ago, the largest specimens reached about 20 feet in length, and belongs to a family called 'mosasaurs', conventionally thought of as gigantic finned marine lizards, similar and perhaps even related to present day monitor lizards. The researchers discovered several fossils of the new species, ranging from small juveniles to large adults that suggest that this species had limbs like a terrestrial lizard, a flattened, crocodile-like skull, and a tail unlike other known members of the mosasaur family.

The fossils were recovered from an open-pit mine in the Bakony Hills of Western Hungary, which were once flood-plains. According to the study, this is the first known mosasaur that lived in freshwater, and only the second specimen of a mosasaur to have been found in rocks that were not once deposited in the ocean. Makadi says, "The evidence we provide here makes it clear that similar to some lineages of cetaceans, mosasaurs quickly adapted to a variety of aquatic environments, with some groups re- invading available niches in freshwater habitats. The size of Pannoniasaurus makes it the largest known predator in the waters of this paleo-environment."

Whether or not Pannoniasaurus was restricted to freshwater environments, or perhaps instead was a seasonal, opportunistic migrant and consumer in these habitats, remains uncertain. Sedimentological, taphonomical, morphological and geochemical evidences suggest the former. In association with the facies analysis and depositional environment interpretations, the collected evidence indicates that Pannoniasaurus is best interpreted as an inhabitant of freshwater ecosystems. Currently, among derived pythonomorphs, Pannoniasaurus, whether being an obligatory freshwater animal or a seasonal or opportunistic migrant, remains the first and only know river-dwelling member of the clade including aigialosaurs and mosasaurs.

Even in the modern world, squamate reptiles in the aquatic world are extremely rare. Only a few species live in the water, and even fewer, like marine iguanas and sea kraits, live in the oceans. The new species described here probably adapted to freshwater environments similarly to river dolphins, such as those now inhabiting the Amazon, Ganges and Yangtze rivers.

The evidence we provide here makes it clear that similar to some lineages of cetaceans, mosasauroids quickly radiated into a variety of aquatic environments, with some groups reinvading available niches in freshwater habitats, and becoming highly specialized within those ecosystems.

Citation
László Makádi, Michael W. Caldwell, Attila Ősi. The First Freshwater Mosasauroid (Upper Cretaceous, Hungary) and a New Clade of Basal Mosasauroids. PLoS ONE, 2012; 7 (12): e51781 DOI: 10.1371/journal.pone.0051781

Wednesday, December 19, 2012

Length–mass allometry in snakes



Arboreal, burrowing, and aquatic boids.
Clue's to an animals life style (aquatic or terrestrial, burrowing or arboreal) are related to its body size and mass. Body size and body shape are closely correlated to an animal’s physiology, ecology and life history, and, therefore, play a major role in understanding ecological and evolutionary phenomena. Since many species are known from relatively few specimens or difficult to observe direct observations is not always possible. But, because organisms often have different shapes, only a uniform proxy, such as mass, may be suitable for comparisons between taxa. Snake masses are rarely reported in the literature. On the basis of 423 species of snakes in 10 families, Feldman and Meiri (2013) developed clade-specific equations for the estimation of snake masses from snout–vent lengths and total lengths. They found that snout–vent lengths predict masses better than total lengths. By examining the effects of phylogeny, as well as ecological and life history traits on the relationship between mass and length, they found that viviparous species are heavier than oviparous species, and diurnal species are heavier than nocturnal species. Furthermore, microhabitat preferences profoundly influence body shape: arboreal snakes are lighter than terrestrial snakes, whereas aquatic snakes are heavier than terrestrial snakes of a similar length.

Citation
Feldman, A. and S. Meiri. 2013. Length–mass allometry in snakes. Biological Journal of the Linnean Society 108:161-172.

Sunday, December 16, 2012

No evidence for erycine boas in North America before the Miocene

Extant erycine boas: An African  Exyx colubrinus, and the North American  Lichanura, and Charina
The central Rocky Mountain Interior has long been a focus of study for late Eocene early Oligocene fossils in North America. The Medicine Pole Hills of North Dakota has preserved abundant late Eocene fossils which provide a glimpse of the central North American fauna prior to the earliest Oligocene cooling. In a forthcoming article, Smith (2012) reports on the fossil snakes of this locality using 179 isolated vertebrae from all parts of the vertebral column as well as cranial elements. The assemblage comprises four species: (1) a primitive burrowing snake (“anilioid”); (2) a small boid related to Ungaliophiinae (dwarf boas); (3) a mid-sized booid related to Loxocemus (Mexican Burrowing Python); and (4) a colubrid. The dwarf boa, Calamagras weigeli, is conservatively regarded as the earliest secure representative of the clade Ungaliophiinae, but the history of this clade may stretch considerably further back. The loxocemid, Ogmophis compactus, is the second reported fossil from that clade. The colubrid is one of the earliest known and could represent the first appearance of colubrine “racers” in North America; it may have had an elongate tail, implying that it was arboreal, but this is not yet clear. Full-column analysis and cranial elements prove crucial for the accurate higher-level identification of snake clades from which these isolated elements derive.

This paper is of most interest because it clarifies the previous idea that Erycinae boas were common in the Paleogene of North America. Today in North America erycines are represented by the rosy boas (Lichanura) and the rubber boas (Charina). In the past many authors assigned most North American Paleogene snake taxa to the Erycinae (sand boas) Smith reports that there is no well-founded record of an erycine boa in North America prior to the Miocene. The mistake apparently resulted from the similarity of mid-body vertebrae in the extant North American Erycinae and the Paleogene snakes. Thus the Eocene North American snake fauna had small booid snakes, but they were in fact members of the loxocemid and ungaliophid clades, not the Eastern Hemisphere sand boas, the Erycinae.

Citation
Smith, K. T. 2012. New constraints on the evolution of the snake clades Ungaliophiinae, Loxocemidae and Colubridae (Serpentes), with comments on the fossil history of erycine boids in North America. Zoologischer Anzeiger - A Journal of Comparative Zoology, http://dx.doi.org/10.1016/j.jcz.2012.05.006

Capuchin monkeys learn to respond or not respond to snakes

Photo credit: Steven G. Johnson
Primates have evolved antipredator behaviors for many potential predators including snakes, crocodiles, caimans, felids, canids, raptors, and other primates. Antipredator behavior includes avoidance, mobbing, alarm calls, vigilance, evasive maneuver/fleeing/seeking refuge, and aggressive behavior based on level of risk.
 
Young animals are smaller and less experienced than adults and thus may be susceptible to a wider range of predators. This risk should lead to strong selection for the evolution of innate predator recognition yet examples of false alarming (alarming at nonpredators) by young primates suggest that this facet of antipredator behavior likely involves experiential refinement of the predator-recognition process. Studies of vervet monkeys, spectral tarsiers, and white-faced capuchin monkeys show that younger individuals alarm call at a wide range of harmless animals, a behavior rarely found in adults. As the individuals age, they become more selective and restrict alarm calling mainly to dangerous predators.

Meno et al. (2012) examined the influence of the social environment on antipredator behavior in infant, juvenile, and adult wild white-faced capuchin monkeys (Cebus capucinus) at Lomas Barbudal Biological Reserve in Costa Rica. Different species of model snakes and novel models. were presented to the capuchins and the authors examined: (a) the alarm calling behavior of the focal animal when alone versus in the vicinity of conspecific alarm callers and (b) the latency of conspecifics to alarm call once the focal animal alarm called. Focal animals alarm called more when alone than after hearing a conspecific alarm call. No reliable differences were found in the latencies of conspecifics to alarm call based on age or model type. Conspecifics were more likely to alarm call when focal individuals alarm called at snake models than when they alarm called at novel models. Results indicate (a) that alarm calling may serve to attract others to the predator’s location and (b) that learning about specific predators may begin with a generalized response to a wide variety of species, including some nonthreatening ones, that is winnowed down via Pavlovian conditioned inhibition into a response directed toward specific dangerous species. This study reveals that conspecifics play a role in the development of antipredator behavior in white-faced

Citation
MENO, W., COSS, R. G. and PERRY, S. (2012), Development of Snake-Directed Antipredator Behavior by Wild White-Faced Capuchin Monkeys: II. Influence of the Social Environment. Am. J. Primatol.. doi: 10.1002/ajp.22109

Monday, December 10, 2012

Origins of the North American Desert Fauna

The Rosy Boa, Lichanura trivirgata.
Phylogeographic studies of the southwestern deserts of North America have suggested diverse historical processes, with two hypotheses posed as most important for shaping genetic structure: climate fluctuations in the Pleistocene and pre-Pleistocene vicariance. Support for the climate fluctuation hypotheses emerged from a historical understanding of Pleistocene vegetation patterns within North American deserts and from the perception that desert floras were relatively young. Environmental reconstructions, based largely on analysis of packrat middens, have suggested that present distributions of the Mojave and northern Sonoran Desert biomes were largely comprised of mesic woodlands during the Last Glacial Maximum (LGM: 18,000−20,000 years ago. Furthermore, these deserts only recently reached their current extents in the present interglacial period Presumably, recent biotic responses of desert habitats to climatic change have also occurred during the repeated glacial/interglacial cycling throughout the Pleistocene (especially over the last 700,000 years. As such, several studies have posited that arid-adapted species spanning multiple deserts would have been limited to isolated refugia within the Mojave and Sonoran Deserts during glacial periods, assuming that niche requirements remained the same over time. Repeated displacement and fragmentation of habitats during climatic fluctuations should have resulted in genetic lineage diversification between refugial populations. Similarly, evidence of demographic expansion within lineages should coincide with the end of the LGM, as desert habitats expanded to maximum distributions.

Wood et al. (2012) investigate the phylogeographic history of the Mojave and Sonoran Deserts using a comparative approach. They examining spatial and temporal patterns of DNA sequence variation in 12 species, and evaluate the concordance of phylogeographic breaks and lineage diversification for both Pleistocene climate fluctuation hypotheses and pre-Pleistocene vicariance hypotheses. And, they used visualization methods to assess the spatial pattern of genetic diversity and divergence across species and identify regional evolutionary hotspots.

In seven of the 12 species, lineage divergence substantially predated the Pleistocene. Historical population expansion was found in eight species, but expansion events postdated the Last Glacial Maximum in only four lineages. For all species assessed, six hotspots of high genetic divergence and diversity were concentrated in the Colorado Desert, along the Colorado River and in the Mojave/Sonoran ecotone. At least some proportion of the land within each recovered hotspot was categorized as protected, yet four of the six also overlapped with major areas of human development.

Eight of the 12 species used were members of the herpetofauna (the red spotted toad, Anaxyrus punctatus the shovel-nosed snake, Chionactus occipitalis; the collared lizard, Crotaphytus bicinctores; the sidewinder, Crotalus cerastes; the rosy boa, Licanura trivirgata; and the horned lizard, Phryanosoma platyrhinos; the spiny lizard, Scleroporus magister; and the night lizard, Xantusia vigilis).

Most of the species examined in this study diversified into distinct Mojave and Sonoran lineages prior to the LGM – supporting the older diversification hypotheses. Several evolutionary hotspots were recovered but are not strategically paired with areas of protected land. Long-term preservation of species-level biodiversity would entail selecting areas for protection in Mojave and Sonoran deeserts to retain divergent genetic diversity and ensure connectedness across environmental gradients.

The entire article is available on-line.

The Beaked Sea Snake, Two Cryptic Species

The deadliest sea snakes in the world can be found from the Arabian Peninsula to Australia. They like to live in estuaries and lagoons near the shore and have been known to get tangled in fishermen's nets and inflict fatal bites. Their venom is extremely toxic, more potent than that of a cobra.

But the deadliest sea snake has a secret — it is actually two sea snake species.
Scientists once thought that snakes in Australia and Asia were the same species, Enhydrina schistosa. The snakes from these regions do look similar, with beaklike mouths that have a notch between the lower jaws.

However, when University of Queensland researcher Bryan Fry and colleagues tested the serpentine DNA, the results showed that they were separate species, and not even close relatives, as noted by the publication Asian Scientist.

This is a case of convergent evolution, wherein different species evolve independently but end up looking quite similar, according to the study, published recently in the journal Molecular Phylogenetics & Evolution. Or, as Yong put it, convergent evolution is "when different species turn up at life's party wearing the same clothes."

Considering that these animals are responsible for the majority of deaths caused by sea snakes, it's important to know the identity of the different species. Luckily, however, the antivenin used to treat bites from the Australian and Asian version of this "species" works on both, according to the study.

Both sea snakes feed almost exclusively on spiny catfish and puffer fishes, which requires the snake to open its jaws very wide. The scientists suggest this is one reason for their similar appearance; the notched jaw allows them to swallow these creatures whole.

The researchers have proposed new names for the sea snakes that will better reflect their evolutionary history. The Asian serpent should retain the name Enhydrina schistosa, they suggest, while the Australian species could be dubbed Enhydrina zweifeli.

Citation
Ukuwela, K.D.B., de Silva, A., Mumpuni, Fry, B.G., Lee, M.S.Y., Sanders, K.L., Molecular
evidence that the deadliest sea snake Enhydrina schistosa (Elapidae: Hydrophiinae) consists of two convergent species, Molecular Phylogenetics and Evolution (2012), doi: http://dx.doi.org/10.1016/j.ympev.2012.09.031

Saturday, December 8, 2012

Suizo Report -- 1,834


I find myself in the midst of my own man-made purgatory. We speak of going through my notes and assembling data. Since the year 2000, I find that I have logged over 20,000 lizards. That number seems unbelievable.  But I did something today that makes this number seem trivial by comparison.

I decided to count vehicles on my way to work this morning. This nearly got me killed--twice. So let me pass on some important safety tips to you all. Don't tug on Superman's cape, don't piss in the wind, and don't EVER count vehicles on your way to work.

My daily commute is 25 miles in. I did my counting between 0630 and 0700. I only counted the cars that were coming at me. This despite the fact that the heaviest traffic was going my way.

And how many vehicles did I count? See the number in the subject box.
That's right: One thousand
eight hundred and thirty four. We can easily double that, because as already stated, I didn't count the cars going my way. And it wasn't even close to rush hour yet!

We can conservatively say that 4 thousand people were doing the same thing as I, within a half-hour time span. In five days of driving one way, 1/2 hour per day, I equal my lizard counts over the past 12 years. 2.5 hours driving = 20,000 people. Over 10,000 hours of field work = 20,000 lizards.

I'm a LOT more comfortable with my lizard count now............

As you local herpers know, we're being basted by above average temperatures of late. Surprisingly, the D'backs and tigers all went to their hibernacula a couple of weeks early, and haven't done anything to speak of since.

Not so with the black-tailed rattlesnakes. Most continued to move throughout November, and two appear to be still actively hunting. We go to pictures for the rest of the story:

Image 1: Female CM17, "Ms. Gus," as viewed on 23 November 2012. She is posed under a dead prickly pear umbrella, a spindly hackberry and trixis above her. While this is a protective little cove, it is not a rock structure in any way, shape or form. There is, however, a cliff about 2 meters behind her, with many crevices and tortoise-like burrows for her to retreat.
Image 2: Here is CM17 again, on 4 December 2012. She has only moved about 15 cm from this photo to the previous. It is entirely possible that she is going in and out of one of the openings in the cliff behind her. It is also possible that she is just staying there--which sets up the scenario of a rattlesnake enduring VERY cold nights--close to freezing.

Image 3: Male CM11, "Gus." This image was also taken on 4 December. Note the rat scat around him. I do believe they are still hunting!
I wish we had stayed with black-tails back when we started with them in 2001. But I sure am glad that we finally saw the light, and started tracking them again. I am in awe of these desert molossus!

Changing subjects, snakes unhinging their jaws in order to eat large prey items is a common misconception. In the past, when I was asked about this myth, I was never able to explain it all properly.

Harry Greene was recently filmed explaining the "how" of it all when it comes to feeding snakes. The film is only 8 minutes long, and I HIGHLY recommend that you take the time to watch it. The way he works the kids in this film is exemplary, and the way those kids worked together to bring Harry's lesson to light at the end of it all is downright hysterical!

Click on the link below, and see for yourself. Nice work, Harry!



Best to all, roger