Tuesday, November 30, 2010

Holocene Horned Turtles


The Lord Howe Island Horned Turtle,  
Meiolania platyceps, is probably the
best known member of the Meiolaniidae.
It is difficult to describe the uniqueness of turtles.  We all consider them reptiles, but technically, they may not be. See post What are Turtles? While only a few hundred species exists today, the number and diversity of turtles was much greater. The very large (some may have exceeded 3 m) horned turtles (family Meiolaniidae) are members of the Centrocryptodira (Eucryptodire) clade that includes many extinct forms. They are thought to have been herbivorous and were heavily armored with bony frills on their heads and club-like tails. Fossils are distributed in time between the Eocene and the Pleistocene, and the fossils are distributed in space in Australasia and South America, suggesting they evolved prior to the breakup of Gondwana. Now it appears the meiolaniid turtles survived into the Holocene and were eaten by humans.

Arthur W. White at the University of New South Wales, and colleagues have now found remains of meiolaniid turtles at the archeological site at Teouma on the island of Efate in Vanuatu (in the Coral Sea). The meiolaniid turtles were found in cemetery and midden layers that dated between 3100 and 2800 years before present (YBP). The site is close to the coastal inlet of Teouma Bay, and on the eastern bank of a stream fringed by mangrove. The people who lived at this site ate a variety of domesticated animals as well as animals gathered from the environment. Among the remains recovered were limb bones and shell fragments of a new species of meiolaniid turte. The cut marks provide evidence that the turtles were butchered and the lack of skulls and caudal vertebrae suggest the turtles were not prepared at the site. The authors name the new species Meiolania damelipi after Willy Damelip of Ambrym Island, Vanuatu . He was a local archaeologist at the Teouma site. The authors consider its placement in the genus Meiolania tentative.

Literature
Gafany, E. S. 1996. The postcranial morphology of Meiolania platyceps and a review of the Meiolaniidae. Bulletin of the American Museum of Natural History, no. 229. 165 pp.

White, A. W., T. H. Worthy, S, Hawkins, S. Bedford, and M. Spriggs. 2010. Megafaunal meiolaniid horned turtles survived until early human settlement in Vanuatu, Southwest Pacific. Proceedings of the National Academy of Sciences 107(35): 15512-15516.

Same Gila Monster, Same Hole, 10 Years Later

Roger Repp reports a story of site fidelity in the Gila Monster (Heloderma suspectum). Here is the story.

Many of you suffered through a THS presentation that I made back in July of 2010, and a few more of you suffered worse at an AHA presentation I did last week. During the course of the presentation, I showed a Gila Monster that I have been quietly watching the past several years.

I used the following characters to demonstrate that this has been the same monster year after year:

1. Butterfly (head)

2. Lazy M (~neck)

3. Donald Duck (duck-shaped marking looking up at lazy M)

4. 5 zits (grouping of 5 dots at the end of the lazy M)

5. Ohio (just behind 5 zits--note how Columbus has grown through the years)

We can add many more, like the thumb about to plunge into the east side of Ohio,and four more zits to the north, etc. Now a history lesson. On 26 November 2000, Bill Montgomery, Gordon Schuett and I found a Gila Monster community on a place we call Hill 97. We were able to grab two Gilas from one hole for a DNA sample. I took pic 1 on this day.I kept checking the holes we found this and other Gila Monsters in that day. They remained empty until December of 2004. Since that time, every year since, one or more Gila Monsters have been in the area. Last Friday, 26 November 2010, I went back to Hill 97. I found "Lazy M" again--exactly ten years to the day from the first sighting. I've heard a lot of people make claims of 20 plus years for wild Gilas in holes. Having seen what I've seen, I believe these claims. But proving them is damn hard to do!


Top photo: Gila Monster "Lazy M" 26 November 2000. Bottom photo: "Lazy M" 26 November 2010
Best to all, roger

Monday, November 29, 2010

The Northern Pine Snake vs Development


Apparently, a population of Northern Pine Snakes (Pituophis melanoleucus melanoleucus) has lost a battle with developers to build the Stafford Business Park in southern New Jersey. Michele S. Byers, Executive Director, New Jersey Conservation Foundation reports that the State of New Jersey recently decided to give away (via 30-year lease) 57 acres of a municipal park. The following is a modified version of Byers' article published on NJTODAY.net. The state approved a diversion of public open space in Ocean County’s Stafford Township so a private corporation could use it for their private profit – a precedent so bad that all taxpayers should be concerned for the future of preserved farms and other open spaces we’ve paid for. The property had been used as a landfill until 1982, when Stafford Township stopped accepting solid waste. Since then, it has been maintained with grasses and has become habitat for threatened and endangered species. In order to receive Pinelands Commission approval for the habitat damage, the developer, town and county signed a Memorandum of Agreement (MOA) to preserve adjacent land, including the recently-capped former landfill. This property is now regenerating back to grassland habitat used by pine snakes moving in and out of the adjacent Stafford Forge Wildlife Management Area. However, the township applied for a “diversion” of the land, so that the developer could build a solar energy generating facility under a 30-year lease. The Pinelands Commission ignored its original agreement to permanently preserve this habitat, and amended its memorandum of agreement to allow for the facility. The N.J. Department of Environmental Protection approved the diversion, lauding the jobs and clean energy the project will bring. The N.J. State House Commission approved the project on Monday, Nov. 22. The state’s diversion process is designed to weigh these proposals against the public’s established interest in the preserved land. And if a case is compelling enough to approve a diversion, the process is supposed to ensure adequate compensation to the public for releasing the land – usually through additional open space gains so there is no net loss of parkland. This is where the Stafford case takes on its more disturbing aspects.

On August 4, 2010, the pressofAtlanticCity.com reported that the Stafford Township Council tabled a public hearing and vote on a controversial ordinance to amend the redevelopment plan for the Stafford Business Park. Residents were frustrated over the plan because of the council's lack of transparency and that council was ignoring the development restrictions set forth in the agreement the township made with the state Pinelands Commission in order to get the Stafford Business Park built.

The Stafford Business Park is a 360 acre project that includes plans to install 1,026 solar panels on the surface of a capped landfill that will produce up to 70 percent of the power needed to operate the business park when it’s fully built out. The 6.5-megawatt facility in southern Ocean County is one of the largest solar power projects being proposed in the state, and is being developed by the Walters Group. The energy that will be produced by the solar farm is said to be enough to power 1,500 homes and eliminate about 6,700 tons of CO2 emissions. The business park also includes a 112-unit affordable housing apartment building that has earned the first LEED Gold certification from the U.S. Green Building Council for an affordable housing project in the state. The retail portion of the park also has met a minimum of LEED Silver certification.

The 370-acre, redevelopment also entailed an environmental remediation process that included the clean-up of two leaching landfills that were contaminating groundwater. The landfill closure efforts were certified by the New Jersey Department of Environmental Protection (NJDEP) in May 2009, according to Walters. The project developers also had to relocate rare plants and build a new habitat for tree frogs and the Northern Pine Snakes, along with implementing an extensive monitoring program.

The threatened and endangered plant and animal survey of the site was done by EcolSciences. Their website (http://www.ecolsciences.com/projects.html) contains the following statement:  "EcolSciences conducted a multi-year study of threatened/endangered plant and animal species on a 360±-acre Stafford Business Park in Stafford Township, Ocean County. This study was used to formulate a Species Management Plan for a MOA entered between Stafford Township, Ocean County, Walters Homes Inc., and the NJ Pinelands Commission. The MOA allowed the closing of a former municipal landfill and the residential redevelopment of the site. As part of the study, several miles of trap lines were monitored daily to capture the threatened Northern Pine Snake. A total of 32 pine snakes were captured of which 16 were implanted with radio-transmitters and tracked three times a week. Four nest sites and two communal den sites were located. Following extensive negotiations with the Executive Director of the Pinelands Commission and his staff, the pine snakes were relocated and construction has commenced."

We know how well snake relocation programs work.

The Northern Pine Snake is also under pressure from Jaylin Holdings, a company that submitted a second application to the NJDEP for a proposed Walmart Supercenter located on Route 37 in Toms River and Manchester Township's in Ocean County. The permit has been turned down as recently as March 16, but Walmart is known for its persistence in developing new stores.  Prior to this action (on January 8, 2010) the New Jersey Department of Environmental Protection made the determination to deny the petition request by the New Jersey Builders Association to amend and remove the "threatened" status of the Northern Pine Snake (Pituophis melanoleucus).

Sources:
Byers article: http://njtoday.net/2010/11/29/this-land-is-our-land%E2%80%A6-but-for-how-long/

Ecolsciences article: http://www.ecolsciences.com/projects.html

Energy and Environmental Leader: http://www.environmentalleader.com/2010/09/01/nj-business-park-proposes-6-5-mw-solar-power-system/

Pinesland Watch (March-April 07): http://www.pinelandsalliance.org/downloads/pinelandsalliance_41.pdf

pressofAtlanticCity.com: http://www.pressofatlanticcity.com/news/press/ocean/article_84afa0b0-5805-5351-ad31-b529d26e3ed3.html

Keeping Some of the Pieces, The Importance of Shade in Cacao Plantations


Cacao and coffee are shade crops that provide habitat for plants and animals dependent upon tropical forest. Unlike corn, they enhance biodiversity in agricultural landscapes locally but they may also have a more global role when they are cultivated in regions of high endemism suffering heavy deforestation. Sulawesi is one of those places that still conceals many undescribed species, but like many other places the forests are being logged and converted into human landscapes. Deforestation and subsequent land-use changes are rampant in the tropics and will eventually force the species that survive the upheaval to use altered habitats such as agro-ecosystems and urban areas that tend to be warmer, drier, brighter and less structurally complex than natural forests.
Southeast Asian amphibians and reptiles are among the most poorly studied and the most threatened vertebrates  (estimated at 30% and 31%, respectively based on IUCN 2008 data). Tropical amphibians and reptiles are highly sensitive to habitat modifications and climate change, making mitigating the effects of land-use change on herpetological diversity in Southeast Asia a conservation priority. Wanger et al. (2010) studied a land-use modification gradient ranging from primary forest, secondary forest, natural-shade cacao agro-forest, planted-shade cacao agro-forest, to open areas in central Sulawesi, Indonesia. They determined species richness, abundance, turnover, and community composition in all habitat types and related these to environmental correlates, including canopy cover and thickness of leaf litter. Human disturbances create environments that favor some species over others. Lizards and snakes for example, thermoregulate by basking in open patches of sun and it may be better to have several (or many) small openings in the canopy than just one large open patch. Therefore, many small openings in the canopy may be a better predictor for species richness and abundance of lizards. Frogs, on the other hand avoid direct exposure to the sun and a closed canopy may be a predictor of their diversity and abundance. Wanger and colleagues used Bayesian model selection to identify the best environmental predictors for amphibian and reptile species richness and abundance, including the lacunarity index (a measure of the degree of gaps) to measure canopy heterogeneity. Their results show that amphibians in Sulawesi were more negatively impacted by land-use changes than reptiles. Amphibian species richness and abundance declined as disturbance increased from pristine forest to open areas, while reptile species richness peaked in natural-shade cacao agro-forest between mildly (secondary forest) and strongly (planted-shade cacao agro-forest) disturbed habitats. Studies done in the Neotropics produced similar responses of amphibians and reptiles to disturbance in humid forests.  Thus conserving species of amphibians and reptiles in tropical environments may be best done long-term by allowing shade trees to rejuvenation on cacao plantations and allowing leaf litter to accumulate.

Literature
Wanger, T. C.,  D. T. Iskandar, I. Motzke, B. W. Brook, N. S. Sodhi, Y. Clough and T. Tscharntke. 2010. Effects of Land-Use Change on Community Composition of Tropical Amphibians and Reptiles in Sulawesi, Indonesia. Conservation Biology 24: 795–802.






Changing Vegetation & the Herpetofauna


Sceloporus undulatus
Managing forests (logging, reforestation, clearing brush, using herbicides, etc) can have unforeseen consequences for wildlife. As vegetation goes through succession it creates a variety of changing micro-environments that favor some species over others, so as the stages of succession change the animal populations change with them. This concept has been long known and its application to rattlesnakes was noted in Philip Tome’s 1845 book, Thirty Years a Hunter. Tome lived in northeastern Pennsylvania and described frequent encounters with Timber Rattlesnakes (Crotalus horridus).  Tome described the early setters burning forests to control rattlesnakes. Of course, in the long term this opened up the canopy and provided more basking sites. Jäggi and Baur (1999) linked the decline of Viper aspis populations to changes in vegetations, and other authors have made similar reports of changes in snake populations to changes in vegetation.

Kevin Shoemaker and James Gibbs of the State University of New York now report that the Eastern Massasauga (Sistrurus c. catenatus) persists as two isolated populations at the eastern edge of the species’ geographic range, and those two populations are threatened by the increasing density of woody plants. They found microhabitat temperatures were substantially lower at the closed-canopy site, where catenatus selected the warmest available basking sites.
At an open-canopy catenatus selected basking sites that afforded greater cryptic cover. And, they recommend the experimental reduction of shrub cover to improve basking habitat at the closed-canopy site. But they caution that management efforts to reduce shrub cover for basking should maintain adequate cryptic cover, (that is the grasses, leaf litter, rocks, and other cover) used by the snakes to conceal themselves.

In another paper, Charlotte Matthews and colleagues (2010) report that the recent use of prescribed fire and fire surrogates to reduce fuel hazards has spurred interest in their effects on wildlife. They conducted studies to determine the impact of “reducing fuel” in forests on amphibian and reptile populations in areas that were twice burned, had the understory cut mechanically, and in an area that had the understory cut mechanically followed by two burns. They trapped the herpetofauna using pitfall and funnel traps. The study was done at the Green River Game Land, Polk County, North Carolina. The results revealed that salamanders were reduced in number in the twice burned, mechanically opened habitats – possibly because this site had reduced leaf litter.  While these same habitats supported larger numbers of lizards and snakes, undoubtedly due to the increased number of basking sites and the newly created thermal gradients.


Literature
Jaggi, C., and B. Baur. 1999. Overgrowing forest as a possible cause for the local extinction of Vipera aspis in the northern Swiss Jura mountains. Amphibia-Reptilia 20:25–34.

Matthews, C. E., C. E. Moorman, C. H. Greenberg, and T. A. Waldrop. 2010. Response of Reptiles and Amphibians to Repeated Fuel Reduction Treatments. Journal of Wildlife Management 74(6):1301-1310.

Shoemaker, K. T. and J. P. Gibbs. 2010. Evaluating basking-habitat deficiency in the threatened Eastern Massasauga Rattlesnake. Journal of Wildlife Management 74(3):504-513.

Tome, P. 1854. (1989 reprint) Pioneer Life; or, Thirty Years a Hunter. Baltimore: Gateway Press.

Saturday, November 27, 2010

Predator Defense in Three Quiet Different Gecko Clades

Geckos tend to be small and rather defenseless lizards. They have the ability to shed their tail, or tear their skin to escape a predator. And, while a few large species may deliver a nasty bite, smaller species cannot. Geckos also seem to lack chemical defenses to repel potential predators and therefore they rely on avoiding predators by detecting their odor, or through cryptic coloration or habits, or by distracting potential predators with their tails. Several recent papers describe ways in which some geckos avoid being eaten.

The Australia, nocturnal, rock-dwelling Velvet Gecko, Oedura lesueurii, lives in the same habitat with centipedes. Pike et al. used a combination of field data and laboratory experiments to determine whether a predatory and venomous centipede (Scolopendridae: Cormocephalus sp.) influences habitat selection by this gecko. In the field, they found centipedes and geckos were syntopic, used crevices beneath rocks with similar physical dimensions, thermal regimes and degree of sun exposure. Not surprisingly, geckos rarely shared rocks with centipedes in the field. In laboratory trials, both geckos and centipedes selected shelters with narrow rather than wide crevices and the presence of a centipede caused juvenile geckos to avoid those hiding places. However, adult geckos continued to select narrow crevices even if these contained centipedes. When the experimenters added centipedes to narrow crevices beneath small and large rocks occupied by geckos, both juvenile and adult geckos exited the crevice, especially if it was under a small rock rather than large rock. Thus, centipedes influence habitat selection by velvet geckos, and anti-predator behaviors of geckos are both size- and context-dependent. In a related project, Webb et al. (2010) tested the responses of the Velvet Gecko to the odors of two snake species. One species, the Broad-headed Snake, Hoplocephalus bungaroides, feeds on geckos (therefore is dangerous), the other, the Small-eyed Snake, Cryptophis nigrescens, feeds on skinks, but not geckos (less dangerous). The authors tested whether predator avoidance by prey was modulated by thermal costs associated with retreat-site selection and in both the presence and absence of thermal costs, Velvet Geckos avoided crevices scented by both dangerous and less dangerous snake species. Their results suggest that Velvet Geckos treat both snake predators as equally dangerous. They repeated the experiments in the field and obtained similar results, the geckos avoided crevices that were temperature - friendly but scented with the odor of snakes- regardless of whether or not the snakes were considered dangerous by the researchers. Suggesting, the Velvet Gecko treats both snakes as dangerous and avoids them.

Alonso et al. (2010) examined the behavior of the Yellow-headed Gecko, Gonatodes albogularis, towards humans (the predators) in three habitats near Bogotá in Colombia. They collected data on the tail display as an observer approached the lizard. During transects geckos were approached by the observer in a standardized way, and details of their tail-waving displays were recorded. In control recordings animals were watched from a distant site without approaching them. Their results showed sexual differences in tail-waving. Male geckos waved their tails more frequently than females. But they found no significant differences between male and female flight distances, nor height above the substrate when the lizards were initially located. Males displayed more frequently than females when approached than when the simulated predator remained stationary. The authors suggest the display functions as a pursuit-deterrent signal to potential predators; but note that some tail displays were performed in the presence of conspecifics, therefore the display may also have a social function.

In southwestern Africa, Higham and Russell (2010) examined how two related species of Namib Day Geckos of the genus Rhoptropus runaway from predators. Rhoptropus afer and Rhoptropus bradfieldi are found in the coastal desert regions of Namibia, and while R. afer commonly runs on sandy substrates and moves between isolated sheets of rock, R. bradfieldi lives and runs on isolated boulders. The morphology of the two species is quiet divergent. The authors recorded the inclination of the substrates, quantified the maximum speed and acceleration of each species on a level track, and measured their seed and acceleration during escapes in the field. They found that R. bradfieldi occupies steeper surfaces than those occupied by R. afer. On the track and in nature, R. afer runs faster than R. bradfieldi. Rhoptropus afer commonly runs for more than 2 or 3 m to escape a predator, whereas R. bradfieldi commonly runs shorter distances, often less than 50 cm during an escape sprint. Higham and Russell concluded that: (1) R. afer attains higher maximum speeds when escaping under controlled and field conditions, although the magnitude differs between conditions; and (2) hindlimb morphology correlates with maximum running speed in R. afer, but not in R. bradfieldi. They propose that these two gecko species represent distinct and highly divergent ecomorphs.

Literature

Alonso, M. L. B., J. M. Cotrina, D. A. Pardo, E. Font and M. Molina-Borja. 2010. Sex differences in antipredator tail-waving displays of the diurnal yellow-headed gecko Gonatodes albogularis from tropical forests of Colombia. Journal of Ethology, 28:305-311.  DOI: 10.1007/s10164-009-0186-4

Higham, T. and A. P. Russell. 2010. Divergence in locomotor performance, ecology, and morphology between two sympatric sister species of desert-dwelling gecko. Biological Journal of the Linnean Society, 101:860–869.

Pike, D. A., B. M. Croak, J. K. Webb, and R. Shine. 2010. Context-dependent avoidance of predatory centipedes by nocturnal geckos (Oedura lesueurii). Behavior, 147:397-412.

Webb, J. K., D. A. Pike and R. Shine. 2010. Olfactory recognition of predators by nocturnal lizards: safety outweighs thermal benefits. Behavioral Ecology, 21:72-77.

Friday, November 26, 2010

An Annotated Bibliography of Homalopsid Snakes 1.1- Now Available

An Updated Version of An Annotated Bibliography of Homalopsid Snakes is now available. PDF

Ecology and Bites of the Humped-nosed Viper


The Western Ghats of southwestern India is a biodiversity hot spot. The western slopes of the mountains experience heavy annual rainfall (with most precipitation occurring from June to September) but the eastern slopes are drier. Rainfall also varies from north to south producing a wide variation in rainfall patterns and thus a pattern of vegetation that ranges from scrub forest to tropical rainforest. Sawant et al. (2010a) examined the distribution and abundance of pit vipers in five wildlife sanctuaries in Goa using seasonal and day-night transects to determine habitat use in three pit vipers: the Bamboo Pit Viper (Trimeresurus gramineus), the Malabar Pit Viper (Trimeresurus malabaricus) and the Humped-nosed Pit Viper (Hypnale hypnale). They found specific habitat preferences for each species and note snake abundance changes with the seasons. The Malabar Pit Viper, Trimeresurus malabaricus, predominantly occupied tropical semi-evergreen forests and rarely used moist deciduous forests while the Bamboo Pit Viper, Trimeresurus gramineus and the Humped-nosed Viper, Hypnale hypnale were mostly in cane brakes, wet bamboo brakes, tropical semi-evergreen, and moist deciduous forests. Unexpectedly, the Hump-nosed Viper made a remarkable change in their habitat use. After the monsoon and into the winter they occupy the cashew plantations adjoining the wildlife sanctuaries. Hump-nosed Vipers are terrestrial and semi-arboreal and Sawant et al (2010b) examined its ecology, threats, and conservation. This little pitviper prefers cool and moist microhabitats. Females using the cashew plantations were more susceptible to human activity. The authors point out that this preference for a particular micro-habitat emphasizes the need for conservation despite the fact most suitable habitat in the Western Ghats, for this species is included in areas already protected.

Bites from the Humped-nosed Vipers are also turning out to be a more serious problem than previously thought. Hypnale hypnale and H. nepa can cause renal failure and haemostatic dysfunctions. Several fatalities due to H. hypnale envenoming, for which there is no specific antivenom, have been reported in India and Sri Lanka. One reason the bites are particularly troublesome is that the snakes are frequently misidentified as Saw-scale Vipers (E. carinatus) in Kerala, India. Consequently, many H. hypnale bite victims end up receiving ineffective antivenom (Alirol et al. 2010; Joseph, et al. 2007). Tan et al. (in Press 2010) report clinical studies indicate the locally available polyvalent antivenoms produced in India are not effective against Hump-nosed Pit Viper venom. Therefore, there is a need for an effective antivenom. Tan et al. examined the ability of the Malaysian Pit-Viper, Calloselasma rhodostoma, monovalent antivenom and the Hemato polyvalent antivenom, both produced by Thai Red Cross Society (TRCS) to neutralize the lethality and toxic effects of H. hypnale venom. They chose this antivenom because C. rhodostoma is considered a sister of H. hypnale. In vitro neutralization studies of Hemato polyvalent antivenom effectively neutralized the lethality of H. hypnale venom (1.52 mg venom/ml antivenom), as well as the hemorrhagic, procoagulant and necrotic activities of the venom. The monovalent C. rhodostoma antivenom also neutralize the lethality and toxic activities of the venom, but the potency was lower. Experiments with Hemato polyvalent antivenom effectively protected mice from the lethal and local effects of H. hypnale venom. Thus the Hemato polyvalent antivenom may be beneficial in the antivenom treatment of H. hypnale envenoming.

Literature
Alirol, E., S. K. Sharma, H. S. Bawaskar, U. Kuch, and F. Chappuis. 2010. Snake Bite in South Asia: A Review. PLoS Neglected Tropical Diseases 4(1): e603. doi:10.1371/journal.pntd.0000603.

Joseph J. K., I. D. Simpson, N. C. Menon, M. P. Jose, and K. J. Kulkarni. 2007. First authenticated cases of life-threatening envenoming by the hump-nosed pit viper (Hypnale hypnale) in India. Transactions of the Royal Society of Tropical Medicine and Hygiene 101: 85–90.

Sawant, N.S., T. D. Jadhav and S. K. Shyama 2010a. Distribution and abundance of pit vipers (Reptilia: Viperidae) along the Western Ghats of Goa, India. Journal of Threatened Taxa 2(10): 1199-1204.

Sawant, N. S., T. D. Jadhav and S. K. Shyama . 2010b. Habitat suitability, threats and conservation strategies of Hump-nosed Pit Viper Hypnale hypnale Merrem (Reptilia: Viperidae) found in Western Ghats, Goa, India. Journal of Threatened Taxa 2(11): 1261-1267.

Tan, C. H., P. K. Leong, et al. 2010. Cross neutralization of Hypnale hypnale (hump-nosed pit viper) venom by polyvalent and monovalent Malayan pit viper antivenoms in vitro and in a rodent model. Acta Tropica In Press, Accepted Manuscript;doi:10.1016/j.actatropica.2010.11.001



World Congress of Herpetolgy 2008 Articles On-Line

The journal Animal Conservation (Volume 13, Supplement s1, December, 2010) has published excerpts from the 6th World Congress of Herpetology which was held in 2008 in Manaus, Brazil. The volume contains 12 articles that focus on invasive species and the spread of the amphibian chytrid fungus. An introductory article by Robert Reed and Fred Krause point out that while some invasive amphibian and reptile species have received a significant amount of attention, such as: the Brown Treesnake, Boiga irregularis on Guam; the Burmese python, Python molurus (=bivittatus) in Florida; the Coquí, Eleutherodactylus coqui, in Hawaii; and the cane toad, Bufo (=Rhinella) marinus, in Australia; other invasive species are poorly known, and emerging as threats to native species and human economies. These include: the Nile Monitor, Varanus niloticus in Florida; the Common Kingsnake, Lampropeltis getula, in the Canary Islands; the boa constrictors, Boa constrictor, on Aruba and Cozumel; and a variety of giant constrictors in Puerto Rico. Also of interest is an article by Schloegel and colleagues that suggests the global trade in the North American Bullfrog, Rana (=Litobates) catesbeiana, as a cause for the spread of Batrachochytrium dendrobatidis. Apparently farms for breeding the North American bullfrog in Brazil were established in the 1930's, shortly after the frog was introduced into the country. Bullfrogs are farmed for human food and the authors investigated the farms to determine if they serve as reservoirs for amphibian disease. They were able to confirm B. dendrobatidis on five farms (78.5% infection prevalence overall) by PCR. This study shows that B. dendrobatidis is prevalent in farmed North American bullfrogs in two Brazilian states (São Paulo and Pará); that that bullfrogs were not dying as the result of infection; a large proportion of the frogs on each farm were infected; when B. dendrobatidis is present in a farm population, it occurs at a high prevalence but a low intensity; and their results support earlier findings from captive and wild bullfrog populations that Litobates catesbeiana are efficient carriers of this pathogen.

The articles are open access and can be found at Wiley Online.



Literature
Reed, R. N. and F. Kraus. 2010. Invasive reptiles and amphibians: global perspectives and local solutions. Animal Conservation, 13:3–4. doi: 10.1111/j.1469-1795.2010.00409.x

Schloegel, L. M., C. M. Ferreira, T. Y. James, M. Hipolito, J. E. Longcore, A. D. Hyatt, M. Yabsley, A. M. C. R F. Martins, R. Mazzoni, A. J. Davies, and P. Daszak, 2010. The North American bullfrog as a reservoir for the spread of Batrachochytrium dendrobatidis in Brazil. Animal Conservation, 13:53–61. doi: 10.1111/j.1469-1795.2009.00307.x


Thursday, November 25, 2010

Mating Systems & Climate Change

A night time boat trip on Bueng Boraphet, one of Thailand's largest wetlands, was expected to produce frogs and snakes. Instead we found chicks of the Pheasant-tailed Jacana (Hydrophasianus chirurgus). They were little balls of feathers with long legs running from lotus leaf to lily pad leaf, and would occasionally disappear under the water. Jacanas are found around the world in the tropics and they have an unusual and relatively rare mating system for a bird, the males incubate the eggs and guard the chicks, while the females move onto another male and produce another clutch of eggs. Jacanas have a classic polyandrous mating system. Hypotheses for polyandry are variable but in the case of the jacana their eggs have an exceptionally high mortality rate because they are laid at the water's edge. Rising water and predators destroy a high percentage of the bird's reproductive effort. Chen et al. (2008) found jacana behavior most parsimonious with the idea that females produced eggs with many males for increasing the survival rate of their offspring. Animal mating systems are diverse and adaptive, and reptiles have an added variable not found in birds, they are ectotherms.

Lacerta agilis. Photo Credit: Rolf Gebhardt
Since 1984, Matt Olsson and colleagues have studied the evolutionary biology of Swedish Sand Lizard (Lacerta agilis). They observed male and female active every day during the mating season from late April to early June. The lizards were active whenever spring temperatures and cloud cover allowed the lizards to thermoregulate. They found variation in the date’s females laid eggs, confirming the impact temperature has on activity and reproduction. Males are more active than females and subsequently have a larger home range than that of the more sedentary females. Male mating tactics vary with body size. Larger males are bright green on the sides of their bodies and are more aggressive; overtly signal their presence to other males. Smaller males are more cryptically colored (less green) and use mating tactics that are “sneaky.”  Sand Lizards are polyandrous with females mating with multiple males and sperm competition is continuous with a “raffles/lottery” effect set by sperm investment. Males regulate sperm transfer during copulation and cryptic female choice on male genotypes. Olsson's previous research found males less related to the female do better in sperm competition. Under the assumption that male activity is enhanced by higher temperatures, the research group made the predictions that warmer years would result in (1) higher mating rate in both sexes, and (2) stronger sperm competition and/or cryptic female choice. During the study period the mean annual temperature increased by 2ºC. The increase in temperature resulted in a greater mate encounter rate, increasing the degree of polyandry and polygyny, and an increase in the number of sires per clutch in the free-ranging Sand Lizards. The increased number of partners produced greater variation in mate quality, and resulted in a decline in the number of sires per clutch. The authors found this agrees with previous lab studies in which females exercised stronger cryptic female choice when male quality varied. Thus, females had some control of decreasing the risk of having malformed offspring - and controlling which males fertilized their eggs. Olsson and colleagues concluded that, “Ultimately, such variation may contribute to highly dynamic and shifting selection mosaics in the wild, with potential implications for the evolutionary ecology of mating systems and population responses to rapidly changing environmental conditions.”

Literature

Chen T. C., Y-S. Lin, and T-S Ding. 2007 (2008). Time Budget of Polyandrous Pheasant-Tailed Jacana (Hydrophasianus chirurgus) during Breeding Season in Taiwan. Taiwania, 53:107-115.

Olsson, M., E. Wapstra, T. Schwartz, T. Madsen, B. Ujvari, and T. Uller. 2010. In hot pursuit: fluctuating mating system and sexual selection in Sand Lizards. Evolution, no. doi: 10.1111/j.1558-5646.2010.01152.x

Wednesday, November 24, 2010

Interview With A Nigerian Snake Charmer

You just can't make stuff like this up. The following is from the AllAfrica.com website, it was posted November 21, 2010. See the video.

One man's meat is another man's poison. In this interview with Augustine Aminu, Alhaji Audu Nadije, a snake charmer, who finds pleasure in playing with snakes, speaks on his trade. Excerpts:

What do you do?

I'm Alhaji Audu Nadije, the snake charmer. I am married to four wives, with children and grand children. I am also the grand commander of snake charmers of Nigeria. I equally sell traditional medicine. My origin is Gashuwa in Yobe State.

For how long have you been in this profession?

I have been in it for the past 51 years and it has been good.

Apart from the snakes, what else do you do?

Like I said earlier, I equally sell traditional medicine. In this business, I have trained young men who sometimes help me in selling my traditional medicines and I have over ten boxes of snakes which we travel with to different parts of the country to do our business. We've even traveled outside Nigeria.

Snakes are dangerous species of reptiles, how do you cope with them, and how do you feel when you are called the snake charmer?

I feel good and always happy. This is because over 50 years, I have been in this act of snake charming. For the hazard, I believe it is God who gave me the wisdom and the powers, so he has been protecting me.

As a professional in this business, I can tell you the species of the snakes and I have them in different species. There is no snake that is not harmful and dangerous to man, but like I said it is God that has given me this business and he protects us in the business.

Is it true that snake charmers die by snake bite

Well, I'm still alive. I have been in this for over 50 years. I believe is it just people who feel they have mouths and so should say something about snake and snake charmers, they are illiterates.

Do you know that even food can be the source of one's death? But, doctors say we should eat food to have strength. So what we are saying is that if God says you will die in a particular condition, that is it, there is no magic that can change it. Like I said the people making this kind of insinuations, to me are illiterates. They should go and do their research before they come out to say anything.

Any memorable moment?

Yes, for the number of years I have been in this profession, there are two days I will never forget in my life.

The first is the day I was traveling in the company of my friend to Yobe and after the performance, on our way back, I had about 50 snakes and they all died. My friend asked what I was going to do, but I told him not to worry. When we got to a big dry tree, I told him there is a snake here. I set firewood to smoke the snake out but to our greatest surprise, the snake was so big that half of it had not gone into the box before it was full. I was confused, but I had to try again with more smoke and at the end of the day, the snake finally came out and went into the box itself and we left. The second experience was in a forest where we went to catch snakes and had an encounter with whirl wind. What amused me was that, as the wind passed by, you will see fire at the place. But I was destined to catch that snake that day. Those are the two days that remain memorable to me.

What is your hope and aspiration in this business?

My prayer is to die a peaceful death. In the whole world, I don't think there is any kind of big shop you will open for me that would make me leave this business of traditional medicine. Even if old age comes and I cannot do anything further, I have young ones who will take over the business until infinity.

Can you estimate the number of snakes you've had since you started this business, and how many do you have at present?

Hmn... its difficult to say this is the number of snakes I have come in contact with since I started this business. But I know I have had so many of them. Presently, I have 47 in these boxes (pointing to some boxes).

What do you feed these snakes with?

We feed them with meat. Do you know they eat good meat? We don't give them intestines. We give them healthy meat which even human being sometimes don't eat. Sometimes we even give them a full goat to eat.

What success have you recorded from this business?

Alhamdulilla, I have really made a lot of fortune from this business of mine; snake charming and traditional medicine. I have cars (the reporter saw five), I have houses; apart from the one I occupy with my family, tenants rent other houses built by me. I am blessed with children and by the grace of Almighty Allah I have been able to conquer hunger. I have gone for the Hajj 13 times. You can see these are some of the things I have been able to achieve all my days in this business.

What is your call to others in this line of business?

I always walk on the part of truth. I advise them to be truthful all the time, they should avoid all forms of evil and embrace peace. There is nothing like peaceful co-existence.

When they give traditional medicine, they should stand by the truth and not deceive people. They should always respect their elders. I do respect my own elders, that is the secret of my long years in this business.

Earlie, you said to catch a snake, you just smoke it out, but we all know it goes beyond that. Can you tell us other things you use?

Ha, ha, ha, you are a funny youngman. I can't tell you my secret. Ask me other questions other than this and I will give you answer. Don't ask this kind of questions because it is our own mystery and we can't let it out like that.

Snakes they say sometimes behave abnormally. How do you handle such situations?

You see, Almighty Allah does his things the way he so wishes. We have encountered a lot of situations in our quest to get snakes in the bush. Sometimes, spirits turn to snakes and that is why if you go after a snake, it will start talking to you.

And if we see a snake talk, we will know that it is a spirit, or sometimes they don't even talk but once we catch them, we will know that they are not just ordinary snakes, but spirits and we allow them to go their way. The risk of this business is enormous.

You said you are the grand commander, do you have an association?

Yes, we have at least about 4,000 members and it was at one of our meetings that I was elected the grand commander.

The issue is that in the whole of these members, there is no one like me. If there is someone who can play with my snakes, he has no medicine like me. If he has medicine like me, he has not traveled like me.

There is no one in this business that has made name like me. Even the person who introduced it in the Northern part of this country, Audu Iro hasn't made name like me. This profession has taken me to many places; Sudan, Central Africa, Cameroon, Niger and so many other countries. I have traveled far and wide. Allah has given me name.

Tuesday, November 23, 2010

More Flying Snakes: U.S. Defense Department looking into ‘flying snakes’

From the NationalPost.com
Erin Valois  November 23, 2010 – 3:21 pm

Forget military dolphins with “toxic dart guns” — the U.S. Department of Defense has a new trick up its sleeve, and it involves flying snakes.

No, the DoD doesn’t plan to use the snakes in combat or as a new strategy in guerilla warfare. Instead, the agency is providing funds for Virginia Tech’s research the aerodynamics of the gliding creatures, according to the Washington Post.

What the Defense Advanced Research Projects Agency plans to do with this research is still unknown (they refused to comment on the Washington Post story), but finding out how these snakes found in Southeast Asia are able to fly could help the U.S. make great improvements to their military technology.

Why is the tree-dwelling Chrysopelea paradisi so special? First of all, these snakes have no appendages — yet they can travel great distances. The researchers found that the snakes are able to get from the top of a tree, nearly 200 feet in the air, to a tree trunk located 783 ft away.

From the Washington Post:

    “Basically . . .they become one long wing,” said John Socha, the Virginia Tech researcher who has traveled extensively in Asia to study the snakes and to film them.

    “The snake is very active in the air, and you can kind of envision it as having multiple segments that become multiple wings,” he said. “The leading edge becomes the trailer and then the trailer become the leading edge.”

The snakes can even rotate in the air and use a special technique that researchers have yet to explain that allows the snake to continue at a certain speed in order to maintain airborne.

Socha’s research will appear in the latest edition of the journal Bioinspiration and Biomimetics.

National Geographic also helped Socha fund his initial research. Below, their video featuring the acrobatics of flying snakes.

Read more: http://news.nationalpost.com/2010/11/23/u-s-defense-department-looking-into-flying-snakes/#ixzz168x8r1MV

Go Here to see the video: http://news.nationalpost.com/2010/11/23/u-s-defense-department-looking-into-flying-snakes/

Flying Snakes

The following story is being carried by Eureka Alert and Science Daily (Nov. 23, 2010). The snake in the photo is Chrysopelea paradis.

Five related species of tree-dwelling snakes found in Southeast and South Asia may just be the worst nightmares of ophidiophobes (people who have abnormal fears of snakes). Not only are they snakes, but they can "fly" -- flinging themselves off their perches, flattening their bodies, and gliding from tree to tree or to the ground.

To Virginia Tech biologist Jake Socha, these curious reptiles are something of a biomechanical wonder. In order to understand how they do what they do, Socha and his colleagues recently studied Chrysopelea paradisi snakes as they launched themselves off a branch at the top of a 15-meter-tall tower.

Four cameras recorded the curious snakes as they glided. This allowed them to create and analyze 3-D reconstructions of the animals' body positions during flight -- work that Socha recently presented at the American Physical Society Division of Fluid Dynamics (DFD) meeting in Long Beach, CA.

The reconstructions were coupled with an analytical model of gliding dynamics and the forces acting on the snakes' bodies. The analyses revealed that the reptiles, despite traveling up to 24 meters from the launch platform, never achieved an "equilibrium gliding" state -- one in which the forces generated by their undulating bodies exactly counteract the force pulling the animals down, causing them to move with constant velocity, at a constant angle from the horizon. Nor did the snakes simply drop to the ground.

Instead, Socha says, "the snake is pushed upward -- even though it is moving downward -- because the upward component of the aerodynamic force is greater than the snake's weight."

"Hypothetically, this means that if the snake continued on like this, it would eventually be moving upward in the air -- quite an impressive feat for a snake," he says. But our modeling suggests that the effect is only temporary, and eventually "the snake hits the ground to end the glide."

The presentation, "Gliding flight in snakes: non-equilibrium trajectory dynamics and kinematics" was given on November 22, 2010

This research is being published in the journal Bioinspiration and Biomimetics.

John J Socha, Kevin Miklasz, Farid Jafari and Pavlos P Vlachos. Non-equilibrium trajectory dynamics and the kinematics of gliding in a flying snake. Bioinspiration and Biomimetics, 24 November 2010.

Chilomeniscus at Iron Mine Hill

On Saturday, 20 November, Patti Mahaney found a Variable Sandsnake (Chilomeniscus cinctus) on the lower north central side of Iron Mine Hill. It is only the second sandsnake seen on the hill during the course of our ten year study. Interestingly enough, the first was found within spitting distance of this one. The snake appeared to be a fresh kill--no ants, no rigor mortis, still very flaccid. When we were finished with the photos, we put the snake back exactly as we found it. Three hours later, it was still there. 24 hours later, it was gone. My own guess is that this is the work of a skunk, ringtail, or possibly rock or ground squirrels. I send this out with the hopes that somebody who is studying sandsnakes can use it somehow. Roger

Monday, November 22, 2010

Butterfly Lizards, Recent Developments


Their bright coloration probably accounts for the common name ― the Butterfly Lizards, for members of the genus Leiolepis . The Butterfly Lizards are found from southern China, Vietnam, Laos, Cambodia, Myanmar, and Thailand southwest through Peninsular Malaysia. Of interest are early suggestions that Leiolepis ‘glides’ from trees (Cantor, 1847). And, Swinhoe (1870) wrote, that “if surprised far from their holes, they spring into the air while running, and, expanding the loose red skin of their sides, skim along the surface of the sand for a considerable distance (say, often 20 yards at a time) and thus reach their retreats at greater speed.” Probably because of these comments in the literature Edward Taylor suggested they “sail” off banks. Losso et al. (1988) measured locomotor performance of Leiolepis belliani running, jumping and parachuting and investigated whether performance capabilities are correlated with morphological features. They also examined the ability of this lizard to flatten its body. Larger lizards fell and ran faster and jumped further. Lizards that were experimentally prevented from flattening fell faster than control lizards. Cantor and Swinhoe comments were apparently exaggerated because a number of other observers have failed to see the behavior and found these lizards only able to run. Losso et al.(1988) concluded that it is unlikely that lateral flattening has evolved as an adaptation for parachuting in Leiolepis, However, they suggest the ability of Leiolepis to flatten its body may function in: thermoregulation; intraspecific communication (male butterfly lizards have brightly marked flanks), and lateral flattening has been observed during male combat. Or, Leiolepis may have evolved the flattening ability to startle predators.

The seven known species of Southeast Asian Buttererfly Lizards have been long considered to belong to the family Agamidae. Four of the seven species are sexually reproducing species: Leiolepis belliana (Gray, 1827); L. guttata Cuvier, 1829; L. peguensis Peters, 1971; and L. reevesii Gray, 1831); and the other three species reproduce asexually (L. boehmei Darevsky and Kupriyanova, 1993; L. guentherpetersi Darevsky and Kupriyanova, 1993, and L. triploida Peters, 1971).

Now, Grismer and Grismer (2010) have described a new asexual species from Binh Chau – Phuoc Buu Nature Reserve, in Vietnam where it is believed to be endemic. The new species, Leiolepis ngovantrii differs from all sexual species of Leiolepis by lacking males and from all asexual species by having nine rows of enlarged keeled scales across the forearm. Grismer and Grismer made phylogenetic inferences based on 700 base pairs of the mitochondrial ND2 region, and suggest L. ngovantrii's maternal ancestor was L. guttata, and found it was also the ancestral species of L. guentherpetersi, L. boehmei, and L. ngovantrii. L. boehmei was recovered as the maternal ancestor to L. triploida. Leiolepis is also of interest because they are often eaten by humans. Recent news reports (November 12,2010) are reporting that the Vietnamese are serving the just described, fast moving, L. ngovantrii in restaurants despite the fact that it is believed to be restricted to the Binh Chau-Phuoc Buu Nature Reserve. While it might be news that the newly described species is being eaten, it has been relatively well known that other members of the genus also find themselves in the kitchens of Southeast Asia.

As for the relationship of the Butterfly Lizards to other lizards, the studies have been a bit confusing. But, Okajima and Kumazawa (2010) have recently used the mtDNA genomes of agamid lizards to sort out relationships and found that within Agamidae, Uromastyx (Uromastycinae) diverged first and Leiolepis  (Leiolepidinae) diverged next. The Uromastycinae and Leiolepidinae are found to be sister to each other, forming a basal clade in the agamids.

Literature
Cantor, T. 1847. Catalogue of reptiles inhabiting the Malayan peninsula and islands, collected or observed by Theodore Cantor, Esq., M.D. Journal of the Asiatic Society of Bengal 16:607-656, 896-951, 1026-1078.

Grismer, J. L. and L. Grismer. 2010. Who’s your mommy? Identifying maternal ancestors of asexual species of Leiolepis Cuvier, 1829 and the description of a new endemic species of asexual Leiolepis Cuvier, 1829 from Southern Vietnam. Zootaxa 2433: 47–61.

Okajima, Y. and Y. Kumazawa. 2010. Mitochondrial genomes of acrodont lizards: timing of gene rearrangements and phylogenetic and biogeographic implications. BMC Evolutionary Biology 10:141. http://www.biomedcentral.com/1471-2148/10/141.

Srikulnath, K., K. Matsubara3, Y. Uno, A. Thongpan, S. Suputtitada, C. Nishida, Y. Matsuda, and S. Apisitwanich1. 2010. Genetic Relationship of Three Butterfly Lizard Species (Leiolepis reevesii rubritaeniata, Leiolepis belliana belliana, Leiolepis boehmei, Agamidae, Squamata) Inferred from Nuclear Gene Sequence Analyses. Kasetsart Journal (Natural Science) 44: 424-435.

Swinhoe, R. 1870. List of reptiles and batrachians collected in the island of Hainan (China), with notes. Proceeding of the Zoological Society of London 1870: 239-241.




Saturday, November 20, 2010

First Fangs


Uatchitodon kroehleri
Jonathan Mitchell, from the University of Chicago, and colleagues (2010) have described what appear to be the oldest known fangs for venom delivery in a tetrapod. The fossilized fangs have been found at three sites in the USA: Tomahawk in Virginia, the oldest of the three sites; Moncure in North Carolina; and the Placerias Quarry in Arizona. Mitchell et al. analyzed teeth from the three locations and found the fossils from Tomahawk had grooves instead of fully developed enclosed canals. The venom conducting canal extended from the base of the tooth to about a quarter of the way to the tip. Slightly older teeth from the site had a longer, deeper groove. Specimens from Moncure and the Placerias Quarry had the groove completely enclosed and there was a seam suggesting the tooth may have been folded to form the canal. Fourteen grooved Uatchitodon teeth were recovered from Tomahawk and another 26 were found at Moncure and Placerias with fully developed canals. The teeth are about 10 mm long. The authors suggest two species are represented by these teeth. Hans-Dieter Sues, one of the authors on this paper had previously named the grooved- tooth species Uatchitodon kroehleri in 1991 and the species with the canalized teeth is named Uatchitodon schneiderii in this paper. Uatchitodon teeth are quite distinctive in that they possess compound serrations and two venom conducting channels on each tooth. Uatchitodon kroehleri has one groove on the labial (outer) surface and another on lingual (inner) surface of the tooth. The grooves form deep invaginations constricting the tooth’s pulp cavity. So what kind of animal was Uatachitodon? Clearly it was not a snake. It was most likely carnivorous, and the authors suggest it is an archosauromorph. Archosauriformes are thought to have evolved as semi-aquatic predators (Family Proterosuchidae) in Pangea during the late Permian. After the Permian extinction event which killed off 95% of all life, about 251 million years ago the large, dominant therapsid reptiles disappeared and allowed the proterosuchids to radiate into top carnivores. Within five million years, in the Triassic the proterosuchids had evolved into a wide variety of terrestrial and semi-aquatic carnivores, niches previously held by the therapsids. Since Uatachitodon is known only from its teeth, placement in the Archosauriformes is quite speculative.However, the parallel between Uatachitodon fang evolution and snake fang evolution is striking. Grooved teeth in an older species and canalized teeth in a later species. Snakes can have no fangs, solid rear fangs, grooved rear fangs, front fangs with canals, and solid front fangs, and in at least one species grooved rear fangs and solid front fangs. Thus, snakes and Uatachitodon appear to have evolved fangs in the same way, solid teeth become grooved, grooved teeth become folded and form a central canal for conducting venom to the venom aperture under high pressure so that venom can be injected into prey.

Literature
Mitchell, J. S., A. B. Heckert, and H.-D. Sues. 2010. Grooves to tubes: evolution of the venom delivery system in a Late Triassic “reptile”. Naturwissenschaften DOI 10.1007/s00114-010-0729-0

Sues, H.-D. 1991. Venom-conducting teeth in a Triassic reptile. Nature 351: 141–143. doi:10.1038/351141a0