Saturday, August 30, 2014

Minnesota prairie snakes

The following is from the Bemidji Pioneer
Elizabeth Baier, MPR.org | 91.3 FM
Jeff LeClere, a herpetologist with the Minnesota Department of 
Natural Resources, holds an American racer snake Wednesday 
morning his team trapped and tagged. Alex Kolyer | MPR news
Kellogg — In a sandy tract of grassland where the Zumbro River empties into the Mississippi, Jeff LeClere wades in waist-high grass.

The scientist’s visit to Weaver Dunes, is the latest foray to the area where researchers have long studied turtles, falcons, bald eagles and other wildlife populations.

But LeClere isn’t looking up. Instead, he has his eyes open for reptiles that slither in the grass. A herpetologist for the Minnesota Biological Survey, LeClere is leading its effort to catalog Minnesota’s snake species and estimate their population.

That mission brought LeClere to the dunes in search of Porchy, a bullsnake, which is one of a half dozen snake species he is tracking in southeastern Minnesota. The region has the most diverse snake population in the state, with 15 of the state’s 17 snake species. Minnesota is home to two venomous snakes, both rattlesnakes.

Bullsnakes are on the decline but it’s hard to know exactly how much, LeClere said, because of their stealthy nature.

With that in mind, researchers have surgically implanted transmitters into snakes to track them. So when LeClere came to the river bank earlier this week, he pulled out a three-pronged antenna, connected it to a radio receiver and pointed it different directions. As the receiver searched for a frequency emitted by a transmitter, he listened for an electronic beep.

“It will let me know exactly where the snake it, which direction I should be going,” LeClere said. “So, for instance, back where we were, over in this direction, you still get the signal, it’s pretty faint. If I move the antenna in this direction, the sound really picks up, that means she’s in this direction.”

Resarchers nicknamed the bullsnake Porchy because she likes to hang out near the porch of a nearby trailer home. Because she was on the move, LeClere followed her path through an abandoned farm field filled with invasive grass and plants over sandy and uneven soil.

If snakes are in decline, he said, Minnesota’s changing landscape may account for that.

“They are a snake that needs large tracks of open prairie, which basically doesn’t exist anymore because all that’s left of our prairie are small, fragmented areas,” said LeClere, who has been collecting data for a year. “So when you get to a place like where we’re studying these snakes and a couple of other areas of the state that still have a decent amount of prairie left, those are worthy of studying.”

The snakes are worthy of study, LeClere said, because their disappearance from the environment can have wider ecological consequences. Snakes are often considered top predators and consume large numbers of insects and small mammals like rats and mice.

But they tend to have a bad reputation and a lot of people are scared of them, often killing them.

“Another misconception is that snakes will chase you. And I’ve heard stories where people swear that snakes will chase them down,” LeClere said. “And believe me, I’ve been chasing snakes all of my life and I’ve never had one chase me, so we’ve had a few people who just vehemently do not like snakes and the probably will never change their mind. But for the most part, people have been very positive.”

After following the sound of Porchy’s transmitter for nearly 20 minutes, the beep grew stronger.

LeClere spotted her near a gopher mound on the ground. She was clearly agitated by the presence of human invaders.

Yellow with black and brown blotches, about 5 feet long and as thick as a tube of toilet paper, Porchy weighs about two pounds.

As LeClere bent to grab her, he noticed the snake’s glistening skin.

“She shed recently,” he said. “She’s got good weight. She’s nice and thick, means she’s been eating well. This is good news because it means she’s behaving normally.”

After a few minutes, LeClere put Porchy back on the ground and the snake disappeared into the prairie.

His job done, he pulled a clipboard from his backpack and began noting his observations on the snake, its behavior and environment.


When the project ends this fall, he hopes to provide reliable information to wildlife manager and landowners about where snakes like Porchy feed, where they nest, and how they move to help preserve an important part of the state’s ecosystem.

Monday, August 25, 2014

Marine crocodilians and sea surface temperatures

A dyrosaurid, a marine crocodilian, swimming in the warm 
surface waters during the end of the Cretaceous period. Illustration 
credit: Guillaume Suan.

The ancestors of today's crocodiles colonized the seas during warm phases and became extinct during cold phases, according to a new Anglo-French study which establishes a link between marine crocodilian diversity and the evolution of sea temperature over a period of more than 140 million years.

The research, led by Dr Jeremy Martin from the Université de Lyon, France and formerly from the University of Bristol, UK is published this week in Nature Communications.

Today, crocodiles are 'cold-blooded' animals that mainly live in fresh waters but two notable exceptions, Crocodylus porosus and Crocodylus acutus venture occasionally into the sea. Crocodiles occur in tropical climates, and they are frequently used as markers of warm conditions when they are found as fossils.

While only 23 species of crocodiles exist today, there were hundreds of species in the past. On four occasions in the past 200 million years, major crocodile groups entered the seas, and then became extinct. It is a mystery why they made these moves, and equally why they all eventually went extinct. This new study suggests that crocodiles repeatedly colonized the oceans at times of global warming.

Lead author of the report, Dr Jeremy Martin said: "We thought each of these evolutionary events might have had a different cause. However, there seems to be a common pattern."

Dr Martin, with a team of paleontologists and geochemists from the Université de Lyon and the University of Bristol, compared the evolution of the number of marine crocodilian fossil species to the sea temperature curve during the past 200 million years. This temperature curve, established using an isotopic thermometer, is widely applied for reconstruction of past environmental conditions and in this case, is based on the isotopic composition of the oxygen contained in the fossilized remains of fossil marine fish (bone, teeth, scales).

Co-author, Christophe Lécuyer explained: "According to this method, it is possible to calculate the temperature of the water in which these fish lived by applying an equation linking the isotopic composition of the fossilized remains to the temperature of mineralization of their skeleton. The seawater temperatures derived from the composition of fish skeleton thus corresponds to the temperature of water in which the marine crocodiles also lived."

The results show that colonization of the marine environment about 180 million years ago was accompanied by a period of global warming of the oceans. These first marine crocodilians became extinct about 25 million years later, during a period of global freezing. Then, another crocodilian lineage appeared and colonised the marine environment during another period of global warming.

The evolution of marine crocodilians is therefore closely tied to the temperature of their medium, and shows that their evolution and their lifestyle, as in modern crocodilians, are constrained by environmental temperatures.

Nevertheless, one fossil lineage does not appear to follow this trend. Jurassic metriorhynchoids did not go extinct during the cold spells of the early Cretaceous, unlike the teleosaurids, another group of marine crocodilians. Quite surprisingly, metriorhynchoids only disappeared a few million years later. This exception will certainly provide grounds for new research, particularly into how the biology of this group adapted to life in the pelagic environment.

Professor Michael Benton from the University of Bristol, another co-author of the study, said: "This work illustrates a case of the impact of climate change on the evolution of animal biodiversity, and shows that for crocodilians, warming phases of our earth's history constitute ideal opportunities to colonise new environments.

Citation

Jeremy E. Martin, Romain Amiot, Christophe Lécuyer, Michael J. Benton. 2014. Sea surface temperature contributes to marine crocodylomorph evolution. Nature Communications, 5 DOI: 10.1038/ncomms5658.

Saturday, August 23, 2014

The identity of the long confused snake Elapotinus picteti



Top left: The snake Elapotinus pictei, Bottom left: a scan of its skull showing
 the rear fangs. Right a map of its distribution showing is association with 
rainforest. Adapted from Kucharzewski et al.
The snake Elapotinus picteti Jan, 1862 has been an enigma, it was described without locality data. The genus and species were both based on the holotype and the species was considered to belong to the venomous African Aparallactinae (family Lamprophiidae) for more than a century. However, the snake was never re-discovered but it was accepted as a valid species until present.

Christoph Kucharzewski of the Museum für Naturkunde’s Leibniz-Institut für Evolutions- und Biodiversitätsforschung in Berlin, Germany and colleagues (2014) have now clarified the taxonomic
status of E. picteti.

The authors compared its characters the literature and identification keys for the snakes across the globe. A literature survey and subsequent study of type specimens revealed that the monotypic Elapotinus is a subjective senior synonym of the monotypic Malagasy pseudoxyrhophiine snake genus Exallodontophis Cadle, 1999, a snake characterized by its unique aglyphous dentition.

Elapotinus picteti is an amazing example how missing locality data, erroneous assumptions and character descriptions can combine and lead to misleading conclusions. Elapotinus was a problematic from the beginning and this in part explains why it took more than 150 years to unravel this taxonomic mystery.

First, there was no type locality given in the original description and the species resembles snakes that evolved convergently in Africa, Madagascar, and South America. Boulenger suggested tropical Africa as possible locality, eighty years later Mahnert suggested a Neotropical origin.
Second, there was uncertainty and confusion concerning the dentition of the species. Jan (1862a, b) described the maxillary teeth of his Elapotinus picteti as ungrooved and the teeth position similarly to Amblyodipsas. Without examination of the type material Boulenger (1896) decided to list the species within the opisthoglyphous Dipsadomorphinae and related to the African Aparallactinae and the Neotropical Elapomorphini. The error regarding dentition introduced by Boulenger led subsequent authors to list the species in the Aparallactinae as part of the family Lamprophiidae from continental Africa.

The authors transfer Elapotinus from the lamprophiid subfamily Aparallactinae to the subfamily Pseudoxyrhophiinae. Furthermore, Elapotinus picteti strongly resembles the Malagasy species Exallodontophis albignaci (Domergue, 1984) in external morphology, coloration and dentition. As a consequence we consider Elapotinus picteti a subjective senior synonym of Exallodontophis albignaci.

Citation

Kucharzewski, C, et al. 2014. A taxonomic mystery for more than 150 years: Identity, systematic position and Malagasy origin of the snake Elapotinus picteti Jan, 1862, and synonymy of Exallodontophis Cadle, 1999 (Serpentes: Lamprophiidae). Zootaxa 3852.2 (2014): 179-202.

Tuesday, August 19, 2014

A new snake from Trinidad, and its significance to the big picture


There is no doubt that there are many, many more species of amphibians and reptiles than previously thought. Peter Uetz, maintains the Reptile Database website, and he recently announced that in 2014, the number of known reptile species passed the 10,000 mark – and the year has not yet ended. In an email Uetz wrote the number of reptile species is, “10,038 species (including 79 described this year), up from 9,952 in April”While some of these species are obviously different, many of them are cryptic, and it takes some detailed study of morphology or DNA to sort them out.

Trinidad is a relatively small island – 4800 square kilometers that has had its herpetofauna relatively well studied. The first list of herps was published in 1858, and the work by Mole and Urich at the turn of the 20th century examined the fauna extensively. William Beebe spent the last years of his life at Simla in the Arima Valley and published a fauna list as well as a paper on the ecology of the valley. Garth Underwood and Michael Emsley also studied and wrote about the island’s herpetofauna. Julian Kenny and Hans Boos were also actively working on the Trinidad herpetofauna for decades. And I made five- or six trips to the islands and examined museum specimens in the 1980-90’s for the 1997 book. During those trips, I frequently stayed at Simla and worked extensively in the Arima Valley. In 2010, I decided to take a second look at the fauna and since that date have made eight trips to investigate the herpetofauna of both Trinidad and Tobago. Additionally, I have been working with colleagues to compare museum material from the islands to those from the mainland – the results are startling.

It has become quite obvious to me that the diversity of reptiles on that 4800 sq km, well studied island (as well as the island of Tobago) is much greater than what I (or anybody else) thought it was in 1990.

Within the last few years, we have described Plica caribeana and Leptophis haileyi. The Plica is a Caribbean Coastal Range species, and the Leptophis appears to be a Tobago endemic. There are more species forthcoming – for the most part it is a matter of time and money to get the work done. But, preliminarily we have identified at least ten more species of squamate reptiles currently unrecognized from the islands or masquerading under the name of a widespread species.

In a forthcoming paper in the Journal of South American Herpetology, Teddy Angarita-Sierra describes a new, cryptic species of coffee snake, in the genus Ninia – from Trinidad. It would normally not surprise me, that a small, leaf litter dwelling snake would go un-noticed in the tropics. But, this snake is surprising because the of the type locality – Simla. A location that has to be the most closely examined piece of real estate on the island – in terms of its fauna.

Ninia atrata left, Nina franciscoi sp. n. right. T. Angarita-Sierra
Angarita-Sierra describes Ninia franciscoi, from a single specimen collected at Simla 6 March 1988 by William B. Montgomery and David Resnick. This specimen looks very much like the widespread Ninia atrata (also found at Simla) except for the number of upper labials contacting the primary temporal and most importantly, an unusually shaped hemipensis (see right).

Nina franciscoi sp n.,top, Nina atrata bottom.
After reviewing this paper – I went back and looked at about forty specimens of Ninia atrata from Trinidad and Tobago as well as all of my photographs, looking to see if any of the others had the primary temporal in contact with three upper labials. Some of these specimens were collected at Simla – none showed this trait.

So, what is the significance of this? Below is a power point slide I used in a recent presentation comparing the number of reptile species per 1000 km2 in Trinidad & Tobago to Venezuela. The islands are much better studied than the mainland. Trinidad & Tobago have 4.2x more known species of reptiles per 1000 km2 than does Venezuela (this is using the numbers from the 1997 book). In other words mainland South America (specifically Venezuela) most likely has a vast number of undescribed reptiles.


As for those undescribed Trinidad and Tobago squamates - one of them is a third species of Ninia. Below is typical Ninia atrata







Vocal communication in Amazon River Turtles

An adult Giant South American river turtle. The turtle 
is the largest member of the side-necked turtle family and 
grows up to nearly three feet in length. Photo credit: C. 
Ferrara/Wildlife Conservation Society
Turtles are well known for their longevity and protective shells, but it turns out these reptiles use sound to stick together and care for young, according to the Wildlife Conservation Society and other organizations.

Scientists working in the Brazilian Amazon have found that Giant South American river turtles actually use several different kinds of vocal communication to coordinate their social behaviors, including one used by female turtles to call to their newly hatched offspring in what is the first instance of recorded parental care in turtles.

"These distinctive sounds made by turtles give us unique insights into their behavior, although we don't know what the sounds mean," said Dr. Camila Ferrara, Aquatic Turtle Specialist for the WCS Brazil Program. "The social behaviors of these reptiles are much more complex than previously thought."

Some behaviors of the Giant South American river turtle have been well known for some time, including the tendency to aggregate in huge numbers during the nesting season. However, the mechanisms used by turtles to coordinate their activities have yet to be explained. This study focused on the sounds made by the turtles as a possible means of facilitating social behavior.

Working on the Rio Trombetas between 2009 and 2011, the research team captured 270 individual sounds made during 220 hours of recording made with both microphones and hydrophones when the turtles were swimming through the river. The scientists then conducted spectrographic analyses on the repertoire, which they subdivided into six different types of vocalization made by turtles during the nesting season, which begins as the reptiles leave the seasonally flooded forest for nesting beaches along river banks. The scientists also sought to correlate vocalizations with specific behaviors.

Sounds made by the turtles while migrating through the river or basking tended to be low frequency sounds, possibly to facilitate contact between turtles over longer distances. Vocalizations made during nesting tended to be higher frequency sounds, possibly because higher frequency sounds travel better in shallow water and in the air.

The highest diversity of sounds are used by females about to nest; the researchers theorize that the animals use these sounds to decide on a specific nesting site and to synchronize their movements (the turtles leave the water in a single-file procession).

The hatchling turtles themselves make sounds before they hatch and continue to do so as they clamber out of the nest chamber on the river beach. The sounds, the authors speculate, may stimulate group hatching. The females, in turn, vocalize in response to the nestling calls, perhaps guiding the nestlings into the water. These interactions -- the first recorded instance of parental care in turtles -- were featured in a 2012 study appearing in the Journal of Comparative Psychology.
Using sonic transmitters, the team also discovered that the hatchlings remain together and migrate with adult females for more than two months.

The Giant South American river turtle is the largest of the side-necked turtle family and grows up to 80 centimeters (nearly three feet) in length. The species is only found in the Amazon River basin and is now threatened by unregulated consumption of the turtles' meat and eggs.

"Groundbreaking studies such as this one can help us better understand the complex relationships between both individual animals and their environment," said Dr. Julie Kunen, Executive Director of WCS's Latin America and the Caribbean Program. "Protecting the still sizable populations of Giant South American river turtles will also enable us to conserve the behavioral richness of these reptiles for future study."

Research on the Giant South American river turtles is part of a new long-term WCS conservation program called Amazon Waters, an initiative focusing on the conservation of aquatic ecosystems and species.

Citation
Ferrara CR, Vogt RC, Sousa-Lima RS, Tardio BMR, Bernardes VCD.  2014. Sound Communication and Social Behavior in an Amazonian River Turtle (Podocnemis expansa). Herpetologica, 70:149 DOI: 10.1655/HERPETOLOGICA-D-13-00050R2


Thursday, August 14, 2014

Boid taxonomy revisited

 
Two phylogenetic trees from recent papers that included boid snakes.
In a new paper Pyron et al. (2014) discuss and alter the taxonomy of boid snakes. The family Boidae previously comprised five subfamilies: Sanziniinae, Charininae, Erycinae, Candoiinae, and Boinae. These subfamilies are distinct both morphologically and biogeographically, with Sanziniinae being restricted to Madagascar; Charininae  found in North and Central America (although Ungaliophis panamensis also inhabits a small portion of western Colombia); Erycinae  ranges from North Africa, Europe, the Middle East, and South and Central Asia; Candoiinae occurs in Oceania; and Boinae is restricted to the Neotropics. However, Boidae was rendered paraphyletic by recent molecular phylogenetic analyses by the African family Calabariidae (Calabaria), which forms the sister-group to Sanziniinae (Reynolds et al. 2014), or all boids to the exclusion of Sanziniinae (Pyron et al. 2013). Therefore, current taxonomy does not reflect monophyletic groups in the analyses sampling the most characters and taxa. Thus, the authors are presented with a number of biogeographically distinct subfamilies, all of which are strongly supported as monophyletic in essentially all recent molecular phylogenetic analyses and by available morphological data. Relationships among these subfamilies are variable, and in some analyses another family-level taxon renders the family paraphyletic. They suggest that the most straightforward action is to change the rank of the boid subfamilies to families, for which family-series names are already available under the Principle of Coordination. This resolves all nomenclatural problems revealed by phylogenetic analyses, as all groups are monophyletic, and relationships among them do not then affect their rank.

Calabaridae contains one genus with one species, Calabaria reinhardtii from West Africa. Calabariids lack of palatine teeth, have premaxillary teeth, the supraorbital bone lacks a dorsal lobe, enlarged head shields, and oviparous reproduction. Calabaria reinhardtii was long considered a python, and it was synonymized with the North American Charina. However molecular phylogenetic analyses clearly show booid affinities, as well as distinctiveness from all other booid genera.

Sanziniidae contains two genera restricted to Madagascar, Acrantophis and Sanzinia. Sanziniids can be distinguished by their mineralized internarial septum with a small fenestra, postorbital and frontal broadly separated by the parietal, distal border of the optic foramen formed mostly by the parietal with anterior margin formed by the frontal, posterior trunk intercostal arteries supply one body segment each, hemipenis with longitudinal flounce, and sulcus terminating below the tips of the arms, as well as other traits. Acrantophis and Sanzinia are more closely related to S. madagascariensis than Calabaria reinhardtii. Previously this group include the Mauritian taxa (the Round Island boas) Bolyeria and Casarea but they are only distantly related and not considered members of the clade under discussion.

Charinidae contains four genera in two subfamilies Charina and Lichanura (Chariniinae) and Exiliboa and Ungaliophis (Ungaliophiinae), Charinids can be distinguished by a distinct lateral muscular bundle (M.) in the jaw known as the adductor mandibulae externus medialis pars anterior, loss of the left lung, as well as other traits. Distribution is in North and Central America, including southern Canada, the western United States and northwestern Mexico for Charininae, and southwestern Mexico, Central America, and extreme northwestern South America for Ungaliophiinae. This group has had a turbulent taxonomic history, but recent molecular results are unambiguous in supporting the monophyly of this group and uniting it with Booidea.

Erycidae contains the single genus Eryx. Erycids can be distinguished by the following combination of characters: transverse process of the premaxilla long, internarial septum of the premaxilla absent, vomerine process of the premaxilla long and narrow, anterior one-third to one-half of the ventral lamina of the nasal decreases anteriorly or is absent, dorsal head scales small and usually asymmetrically arranged, and 34 diploid chromosomes, as well as other traits. Distribution ranges from Southeastern Europe, northern Africa, Middle East, and southwestern Asia. Fossil remains from North America have been assigned to this clade, it will be interesting to see of Erycids were actually present in North America or, the remains belong to another clade – which seems more probable.

Candoiidae contains one genus, Candoia.  Candoiids can be distinguished by the following combination of characters: low distinct posterior hypapophyseal keel on trunk vertebrae, lack of labial pits, lack of paired common carotid arteries, flattened rostrum leading to an angular snout, dorsal margin of the transverse process of the premaxilla adjacent to the nasal process forms a thin high wall noticeably curved posteriorly, body scales keeled, hemipenis with well-defined longitudinal flounce and sulcus terminating below the tips of the arms, as well as other traits. Distribution. Candoiidae is restricted to the Pacific islands of New Guinea and Melanesia, and the eastern Indonesian archipelago. One species occurs in the Palauan archipelago of western Micronesia. Divergence-time estimates support a vicariant origin of Candoiidae with intermediate extinction from other Gondwanan landmasses, as early divergences in Boidae pre-date the final breakup of Gondwana.

Family Boidae contains five genera, Boa, Chilabothrus, Corallus, Epicrates, Eunectes. Boids can be distinguished by the following combination of characters: internarial septum with large fenestra, anterior margin of the ventral lamina of the nasal indented in lateral view, anterolateral margin of horizontal lamina of nasal noticeably indented viewed dorsally, horizontal lamina of the nasal does not overlap dorsal surface of frontal, shallow labial pits and other traits. Distribution is restricted to the New World tropics, from northern Mexico to Argentina, and the West Indies.

Citations
Pyron, R. A., Reynolds, R. G., & Burbrink, F. T. (2014). A Taxonomic Revision of Boas (Serpentes: Boidae). Zootaxa, 3846(2), 249-260.

Pyron, R.A., Burbrink, F.T. & Wiens, J.J. (2013) A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology, 13, 93. http://dx.doi.org/10.1186/1471-2148-13-93.

Reynolds, R.G., Niemiler, M.L. & Revell, L.J. (2014) Toward a Tree-of-Life for the boas and pythons: multi locus species-level phylogeny with unprecedented taxon sampling. Molecular Phylogenetics and Evolution, 71, 201–213. http://dx.doi.org/ 10.1016/j.ympev.2013.11.011.


Reptiles replace dogs as most popular pets


Reptile shows display many species, often unexpected species.
such as this Varanus salvadorii. JCM
The following story was published on-line at the Hexam Courant

By Joseph Tulip, Wednesday, 13 August 2014

The archetypal English family home wouldn’t be complete without a four-legged friend, a bird in a cage to converse with or perhaps a fluffy cuddly companion.

But if we look closely into the alcoves of Tynedale’s front rooms, we might find exotic creatures more commonly associated with the wild.

For in recent years, more people have been taking in reptiles and amphibians as pets, and research has shown they are now starting to outnumber old favourites, such as dogs and cats, in the household.

Residents in Haltwhistle voiced their concerns last week after Joe Reed and Jan Mitchinson moved into a house at the town’s west end with their three boa constrictor snakes and a smaller, speckled king snake, and began walking the streets with them wrapped around their necks and arms.

Fears for the safety of children and small dogs have surfaced in a rural community more familiar with the sights and sounds of sheep and cattle.

Now the couple have been joined by other reptile enthusiasts in allaying fears over the non-venomous species, which is fast becoming domesticated.

Sonya Miller, manager at Hexham’s Rainbow Pets on Battle Hill, who keeps a boa constrictor at home, says reptile sales are nothing new, although snakes and lizards were perhaps more popular in urban areas until recently.

She said: “My husband, Mark, opened a reptile shop in Sunderland 20 years ago. It has maybe taken a while to filter out into more rural areas. There is certainly a market for this type of pet now.
“I think there are definitely trends. Pogona, which is commonly known as a bearded dragon, is popular at the moment, and there has been a craze over the past couple of years for pygmy hedgehogs.”

Rainbow Pets stocks gecko lizards, as well as tortoises and more traditional offerings, such as budgies, canaries and finches.

Assistant Celia Sanderson said: “Everyone is different, so there is a demand for many different types of pet. People have to remember you must be willing to be responsible for it for 20 years or so”.

Jessica and Richard Wilson, of Stonehaugh, have a corn/rat snake cross which Richard obtained when he was a teenager.

Now aged 18, and at just over 3ft long, the reptile is very much part of a family which also looks after two dogs and a cat.

Jessica said: “Snakes are something a bit different and I think that is a factor in the rise in their popularity.

“They are fascinating for children and teenagers and perhaps that is what encourages a lot of parents to buy them.

“Also, snakes are relatively cheap to keep and fairly low maintenance, which means they are a good fit for busy working people.”

Unlike dogs, snakes don’t require daily walks along the riverside, and they can sometimes go weeks, or even months, without eating.

But there some cons, for the owner must be prepared to buy frozen rats and mice to feed their pet snakes, store the rodents and defrost them to provide meals when required.

Reptiles have been big business for Pets At Home since the national retailer opened the doors of its new Hexham store in April.

Deputy manager Laura Findlay said the store offers the likes of royal pythons and other snakes of varying sizes, with its staff trained to ensure customers know exactly what they are taking on board.

She explained: “You might not think it, but they are fairly simple to keep as pets and they do fit in with a busy lifestyle.

“Snakes only eat once a week and go to the toilet once a week. Their cages don’t need to be cleaned out every day, and if they are handled often, they are not time consuming because they get used to human contact.

“However, there are some key issues which people need to be aware of because owning a snake or a lizard is a big responsibility.

“You must be able to offer them the right environment where the temperature is warm.
“You must be prepared for their eating needs – feeding them vermin – and also for the size they can grow to.”

Laura admits that safety can be an issue if owners are not aware of the potential dangers.
She added: “Of course, a snake is capable of causing injury when it constricts. We never let a reptile go without the customer being made aware of their responsibilities in terms of their own welfare and that of other people and the reptile itself.

“We advise people who are new to this type of pet to educate themselves and once they have done that, they should enjoy years of happiness with them.”

Laura said reptiles have taken over from the likes of hamsters in the popularity stakes, possibly because the rodents are nocturnal and not always active when children want to spend time with them.

Domestic rats, gerbils, and tropical fish are also popular choices at Pets At Home. Joe Reed, of Haltwhistle, who featured in last week’s Courant, said he became intrigued by snakes about 25 years ago when he saw a man on the promenade at Blackpool with a boa constrictor, allowing people to have their photos taken with it.

“I was fascinated, and since then I have kept snakes,” said Joe. “They are friendly and placid creatures. I think people have been shocked at me walking about with them in public, but I believe it’s good to get them some fresh air.”

It has been suggested that Tyndedale’s famous black cat – which many people claim to have spotted around the district over the past two decades – may be an exotic form of species discarded by its owner because of licensing issues.

Many snakes and other reptiles don’t require a licence, but the RSPCA does have concerns about whether the needs of such animals can be met in a home environment, and offers advice at www.rspca.org.uk.

Statistics published by the British Federation of Herpetologists in 2008 revealed there were eight million reptiles and amphibians being kept as pets in the UK, compared to an estimated dog population of 6.5 million.


Wednesday, August 13, 2014

Geckos use toe hairs to turn stickiness on and off

Geckos' feet are nonsticky by default, but they can activate 
"stickiness" through application of a small shear force. 
Photo credit: Image by Bjørn Christian Tørrissen,
If you've ever spent any time watching a gecko, you may have wondered about their uncanny ability to adhere to any surface – including upside down on ceilings. It turns out the little lizards can turn the “stickiness” of toe hairs on the bottom of their feet on and off, which enables them to run at great speeds or even cling to ceilings without expending much energy.

In the Journal of Applied Physics, from AIP Publishing, Oregon State University (OSU) researchers describe their work exploring the subtleties of geckos’ adhesion system mechanism.

“Since the time of the ancient Greeks, people have wondered how geckos are able to stick to walls – even Archimedes is known to have pondered this problem,” said Alex Greaney, co-author and an assistant professor of engineering at OSU. “It was only very recently, in 2000, that Kellar Autumn and colleagues proved unequivocally that geckos stick using van der Waals forces.”

Van der Waals forces are weak atomistic level forces, “but geckos are able to take advantage of them because of a remarkable system of branched hairs called ‘seta’ on their toes,” Greaney explained. “These seta and their hierarchy can deform to make intimate contact with even very rough surfaces – resulting in millions of contact points that each are able to carry a small load.”

Geckos – as well as spiders and insects – have independently evolved the same adhesion system mechanism and have been using it for millions of years.

“Understanding the subtleties of the process for switching stickiness on and off is groundbreaking,” said Greaney. “By using mathematical modeling, we’ve found a simple, but ingenious, mechanism allows the gecko to switch back and forth between being sticky or not. Geckos’ feet are by default nonsticky, and this stickiness is activated through application of a small shear force. Gecko adhesion can be thought of as the opposite of friction.”

Greaney and colleagues also found that the entire process is quite subtle, so a synergistic combination of angle, flexibility, and extensibility of the hairs exists that results in incredibly robust and tough adhesion – but still allow geckos to unstick without expending energy.

So, what kinds of applications will these findings enable? For the past 10 years, many researchers have been trying to create ‘synthetic dry-adhesives’ to replicate the gecko. In fact, these types of adhesives are already being used in climbing robots that can search through earthquake rubble in search of survivors.

One application of the team’s work will be put to use improving these synthetic adhesives. “While we don’t envision Mission Impossible sticky gloves, which are inspired by or based on the concept of gecko adhesion, we envision that robots will use gecko adhesion in extreme environments in the future,” Greaney said.

What’s next? “One of the really cool things that we’ve found is the way seta can absorb a large amount of energy, but also can recover it,” Greaney said. “Absorbing energy makes for a tough adhesive joint – for the gecko, it means it can catch itself after jumping or falling and also enables a gecko to rapidly dart off in different directions to avoid predation.”

It’s surprising that the easy detachment mechanism can recover this stored energy, so the researchers are interested in studying whether this is coupled with other aspects of the gecko’s physiology to enable it to take advantage of the recovered energy – much like a kangaroo does when bounding. “We’re also interested in exploring how this robust, but switchable behavior, has the collective behavior of seta in a hierarchical system,” Greaney added.
Citation
Congcong Hu and P. Alex Greaney. Role of seta angle and flexibility in the gecko adhesion mechanismJournalof Applied Physics, August 12, 2014 DOI:10.1063/1.4892628


Thursday, August 7, 2014

Sperm storage in the coastal taipan

Hatching Coastal Taipans. Photo credit: Luke Allen
A snake curator studying in Darwin may have solved a puzzle that has confused experts for years.

Just how can some female snakes store sperm after mating, sometimes for months, before using it to fertilize their eggs?

The rare phenomenon has been recorded in snakes in different parts of the world.

Now Luke Allen, who curates a venom laboratory in South Australia, has used his captive snakes to find out how.

Studying the coastal taipan, Australia's longest venomous snake and one of the deadliest snakes in the world, he learned that the snakes can store sperm for up to six months after mating.

To do so he believes they use special cells in their bodies that secrete sugars and proteins to keep the sperm alive.

The sperm are kept in small pockets along a spongy tube that leads to the snakes' ovaries.
"It had been known that they had this ability but we didn't know how or why," said Mr Allen, who studies Environmental Science at Charles Darwin University.

His six-year study also hinted at why snakes store sperm for such long periods.

The answer is bad news for people who dislike the creatures, which live in northern Australia and parts of Papua New Guinea.

"We found it was related to the food available," he said.

By altering the number of rats he gave them to eat, Mr Allen learned that when conditions were good the snakes could give birth to three clutches of eggs after a single mating.

Storing the sperm from a single coupling meant they could produce three times as many eggs than would have been possible if they did not have the ability.

If times were tough and the snakes were not fed as much they used the sperm all at once.
Mr Allen said while conditions for coastal taipans were fairly stable, the snake was a close relative of the inland taipan, which sometimes had to go for years between rainy periods in Central Australia.

It is this variability which may have given rise to the unusual ability.

But the coastal taipan is not the only snake in the world to be able to delay the fertilization of its offspring.

A rattlesnake in the USA kept alone in captivity for five years unexpectedly gave birth in 2010 to 19 neonates, according to a report.

Other snakes can have so-called "virgin births" where they give birth to healthy young without the need to mate.


Tuesday, August 5, 2014

Suizo Report -- Godzilla and her pups

Howdy Herpers,                                                                                  08/05/14

Sorry that it has been such a long time since I've written all you little people in my life. What with being president of the Tucson Herp Society, running a machine shop, and carrying the full brunt of organizing a radio telemetry study, I don't even have time to pick my nose any more. You want to see? Take a peek up either nostril. Nothin' but nose hairs with crusty booger stalactites clinging to them. A veritable hairy booger garden.

First off, the news is that John Slone found a snake on our plot. Don't bother congratulating him, as he as full of himself as he can be of late. If he were any more modest about it all, he'd be insufferable. Marty Feldner was with him when this snake was found. This made Marty an accessory to John's find, and he also has bit of afterglow going on about it all. When they handed me the bag, they also handed me an excuse as to why they didn't finish their side of the plot. They ran into what they called "an interloper." The snake in the bag was the interloper, and indeed, when a snake is captured in the proper fashion in the framework of the Suizo Mountain Project, it becomes an interloper. It's hard to write up old friends when new friends keep interloping.

John and Marty also possess some psychic prowess. As further explanation tumbled forth from their gullets about the interloper in the bag, they went on to
say it was a black-tailed rattlesnake, it was a female, and it was quite pregnant. Much later, the following morning, as I prepared, sanitized, and quarantined
the container, I realized how much their interloper intertwined with my life. However, as soon as our new molossus was dumped out of bag and into its sterile environs, I also grew psychic. It was indeed a molossus, it was indeed a female, and it was so pregnant that a gentle squeeze to the flanks would certainly jettison piles of baby rattlesnakes and the accompanying ooze that encapsulates them.

The first thought was "get a transmitter in her and get her back in the game." This was my big chance to actually nail some wild birthing behavior on the part of molossus. With this in mind, a drive to a favored DVM in Tempe transpired. The good Dr. DeNardo took one look at that snake and said "NO WAY." The normally fearless vet saw the hopelessness of the situation. There was no choice but to let nature take its course--at my house.

On 25 July, between the hours of 0700 and 1800, our girl dropped eight kids. Typing boy got excited, and started shooting images like a Colorado schoolboy.
But the newspaper background left something to be desired. Typing boy next bagged all the snakes, and filled the container with a substance best described as dusty yard dirt. The ambiance of this all natural enclosure required a hide box, and a convenient black plastic box swiped from Gordon Schuett was selected in order to assure that any photographs were doomed to fail. A whirlwind of photography then ensued, the results of which were highlighted when the little neonates crawled through the water dish and left dust streaks all over the enclosure. Tying boy then got wise, removed all the snakes from the container again, put my long-suffering wife Dianna to work making a sturdy cardboard hide box, and then pet store gravel and genuine Suizo rocks were added. (Some choice language was directed at my "can't-leave-a-snake-on-the-ground-companions" during this process).

The positive evolution of the container will be noted in the images that follow, but I'm sure that any photographers in this group (all of you!) will note that there is still room for improvement. This improvement will transpire as soon as these little bastards all shed. Then, we'll bag everybody up again, sterilize the container again, further cussing at Slone and Feldner will transpire, prickly pear cactus will be chopped off my yard plants, the nearest Neotomamidden will be picked clean, and some GENUINE nature faking will transpire.

It's time to go to images.

Image 1: Godzilla in situ. I wonder how Slone and Feldner knew she was pregnant? 

And how did Godzilla get her name?

Image 2: Note the ventral scales on this snake. Kind of looks like Godzilla is trying to break out, doesn't it?



All the rest: Have a little mercy on the photographer. It would sure be nice if these neonatess were pretty. They aren't. They are ugly little olive drab turds. They fell out of the ugly tree and hit every branch on the way down. Never-the-less, they ARE molossus. And I may never get another opportunity like this again. We can hope that when these little bastards finally shed, they look nicer for the final shoot. Nature faking is best when the snakes are pretty.







Until then, 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.

Monday, August 4, 2014

Selective logging damages mammal and amphibian diversity

This is a tree downed by logging in Madagascar. Photo credit: 
Zuzana Burivalova
The selective logging of trees in otherwise intact tropical forests can take a serious toll on the number of animal species living there. Mammals and amphibians are particularly sensitive to the effects of high-intensity logging, according to researchers in the Cell Press journal Current Biology on July 31 who conducted a meta-analysis of almost 50 previously published studies from around the world.

"Selective logging in the tropics is not a new phenomenon, and it will continue to be a common use of the forest," says Zuzana Burivalova of ETH Zurich, Switzerland. "We hope that this study will help make selective logging more biodiversity friendly in the future."

Individually, those previously published studies had presented an inconclusive and sometimes conflicting picture of the consequences of the selective removal of trees from tropical forests, the researchers say. By combining those studies, they hoped that some overarching patterns would emerge, and indeed they did.

The new findings indicate that the number of mammal species drops in half at a logging intensity of about three or four trees per hectare of forest. Amphibian diversity is halved at a logging intensity of about six to seven trees per hectare, the researchers found. (A hectare is a standard unit of land measurement equal to 10,000 square meters, approximately the size of two American football fields.)

Based on invertebrate surveys, primarily representing butterflies, dung beetles, and ants, Burivalova and her colleagues found further diversity losses with logging. Surprisingly, they found that the number of bird species can actually increase in selectively logged areas, likely because birds lost as a result of the disturbance are replaced by other, more generalist species.

Burivalova calls on logging companies to respect logging intensity thresholds that take biodiversity into account. She and her colleagues say that even forests that are currently under sustainable management may be logged at intensities that are far too high for amphibian or mammalian diversity.

"The current logging quotas are designed predominantly to manage the forest for sustainable timber production such that a forest will eventually regenerate its timber stock," Burivalova says. "They are typically not managed for maintaining faunal biodiversity. This is partly because until now it was not clear at what point exactly diversity in logged forests starts decreasing."

She suggests that consumers can help by paying greater attention to the sources of the wood in furniture, musical instruments, and other products they buy, although she notes that this information is often difficult to come by.

Citation
Zuzana Burivalova, Çağan Hakkı Şekercioğlu, Lian Pin Koh. Thresholds of Logging Intensity to Maintain Tropical Forest Biodiversity. Current Biology, 2014; DOI: 10.1016/j.cub.2014.06.065


Amphibians as travlers

Pseudophilautus poppiae, a microendemic shrub frog from 
Southern Sri Lanka that only occurs in a few hectares of 
cloud forest. Photo credit: Alex Pyron
There are more than 7,000 known species of amphibians that can be found in nearly every type of ecosystem on six continents. But there have been few attempts to understand exactly when and how frogs, toads, salamanders and caecilians have moved across the planet throughout time.
Armed with DNA sequence data, Alex Pyron, an assistant professor of biology at the George Washington University, sought to accurately piece together the 300-million-year storyline of their journey.

Dr. Pyron has succeeded in constructing a first-of-its-kind comprehensive diagram of the geographic distribution of amphibians, showing the movement of 3,309 species between 12 global ecoregions. The phylogeny -- or diagram of evolutionary relationships -- includes about half of all extant amphibian species from every taxonomic group.

"There have been smaller-scale studies, but they included only a few major lineages and were very broad," Dr. Pyron said. "What we needed was a large-scale phylogeny that included as many species as possible. That allows us to track back through time, not only how different species are related, but also how they moved from place to place."

His findings, which appear in the journal Systematic Biology, suggest that, contrary to popular belief, certain groups of amphibians may have swam long distances from one landmass to another within the past few million years.

Biologists have long hypothesized the distribution of extant lineages of amphibians has been driven by two major processes: vicariance and dispersal.

Vicariance occurs when a population is separated following a large-scale geophysical event. After the fragmentation of supercontinent Pangaea and the subsequent split of the Laurasian and Gondwanan landmasses, certain groups of amphibians were able to "hitch a ride" from one continent to another, Dr. Pyron explained. The researcher's biogeographic analysis supports this hypothesis, showing that continental movement can explain the majority of patterns in the distribution of extant species of amphibians.

Dr. Pyron also found that dispersal during the Cenozoic Era (66 million years ago to the present), likely across land bridges or short distances across oceans, also contributed to their distribution.
Given their ancient origin, it is unsurprising that the history of amphibians is a mixture of both vicariance and dispersal. But the third and final distribution pattern that Dr. Pyron notes in his study was an unexpected finding.

Past studies have assumed that long-distance over water dispersal was essentially impossible for amphibians due to salt intolerance. However, when Dr. Pyron began completing his analysis, he noticed a number of cases of distribution that could not be explained by old age.

For instance, one group of frogs found in Australia and New Guinea (pelodryadine hylids) that originated around 61 to 52 million years ago is deeply nested within a group of amphibians that exist only in South America. By the time pelodryadines originated, all major continental landmasses occupied their present-day positions, with South America and Australia long separated from Antarctica.

"They're 120 million years too late to have walked to Australia," Dr. Pyron said.

So how could this group of South American amphibians be related to frogs on the other side of the world?

"You wouldn't think that frogs would be able to swim all the way there, but that seems like one of the more likely explanations for how you could have such a young group nested within South America and have it somehow get to this other continent," Dr. Pyron said.

In his study, Dr. Pyron points two other instances of long-distance oceanic dispersal.

"What you have is this mixture of processes. You have vicariance, which over 300 million years has put certain groups in Africa, some in Australia and others in South America," Dr. Pyron said. "But even more recently, within the last few million years, you have these chance events of long distance dispersals across the ocean, which can influence distribution patterns."

Dr. Pyron's next research question is whether there is any specific quality, such as tolerance to salt water, which allows some groups of amphibians to be better dispersers. He has also begun to conduct a similar analysis with lizards and snakes to see if the same distribution patterns hold up. And as new species are discovered, Dr. Pyron will continue to revise his model.

These findings not only provide evidence for the unlikely hypothesis of long-distance oceanic dispersal, but they also provide a model for explaining the distribution of other species and learning about the geographic diversity of different groups. For example, an endangered frog in South America unconnected to any other major lineages would need to be a high conservation priority.

"That's something we can only learn from a biogeographic analysis," Dr. Pyron said.

Citation
Pyron, RA. 2014. Biogeographic Analysis Reveals Ancient Continental Vicariance and Recent Oceanic Dispersal in Amphibians. Systematic Biology,  DOI:10.1093/sysbio/syu042