Thursday, March 20, 2014

Rukwanyoka holmani; the oldest advanced venomous snake

A vertebrae of the oldest fossil venomous snake 
Rukwanyoka holmani in Africa. Photo Credit:
Ohio University.
Ohio University scientists have found the oldest definitive fossil evidence of modern, venomous snakes in Africa, according to a new study published March 19 in the journal PLOS ONE.

The newly discovered fossils demonstrate that elapid snakes—such as cobras, kraits and sea snakes—were present in Africa as early as 25 million years ago, said lead author Jacob McCartney, a postdoctoral researcher in the Ohio University Heritage College of Osteopathic Medicine. He's part of a team that has been examining the Rukwa Rift Basin of Tanzania over the last decade to understand environmental change through time in the East African Rift System.

Elapids belong to a larger group of snakes known as colubroids, active foragers that use a variety of methods, including venom, to capture and kill prey.

Colubroid fossils are documented as early as 50 million years ago. But they weren't expected to constitute such a large part of the African snake fauna 25 million years ago, as they became dominant in Europe and North America much later.

"In the Oligocene epoch, from about 34 to 23 million years ago, we would have expected to see a fauna dominated by booid snakes, such as boas and pythons. These are generally 'sit and wait' constricting predators that hide and ambush passing prey," McCartney said.

In fact, the recent study includes a description of the oldest evidence of African booid snakes, he said. The researchers have named this new species Rukwanyoka holmani; the genus name combines the Rukwa region name with the Swahili word for snake, and the species name is in honor of J. Alan Holman, a paleontologist and mentor.

However, the team was surprised to discover that the fauna actually revealed more colubroids than booids. That higher-than-expected concentration of colubroid snakes suggests that the local environment became more open and seasonally dry—and, in turn, more hospitable to these active foraging types of snakes that don't require cover to hide and ambush prey—at an earlier time in Africa than in most other parts of the world, as documented in previous studies.

"This finding gives further strength to the idea that tectonic activity in the East African Rift has helped to shape animal habitats in fascinating ways," said Nancy Stevens, an associate professor of biomedical sciences at Ohio University and co-author of the study. "The fossils suggest a fundamental shift toward more active and potentially venomous snakes that could exert very different pressures on the local fauna."

More fossils from additional locations should indicate whether colubroid snakes dominated all of Africa during the Oligocene or just the local region around the Rukwa Rift, McCartney said.

The study published in PLOS ONE describes eight different types of fossil snakes from the Rukwa Rift (five colubroid and three booid), with vertebrae ranging in length from 2.6 mm to just over 5 mm.

Citation
McCartney JA, Stevens NJ, O’Connor PM (2014) The Earliest Colubroid-Dominated Snake Fauna from Africa: Perspectives from the Late Oligocene Nsungwe Formation of Southwestern Tanzania. PLoS ONE 9(3): e90415. doi:10.1371/journal.pone.0090415


Monday, March 10, 2014

Jurassic sites link fossil communities of amphibians, reptiles, and mammals

The fossil salamander Chunerpeton shows the
preserved skeleton, the skin, and  external gills.
Photo Credit: Society of Vertebrate Paleontology.

Over the last two decades, huge numbers of fossils have been collected from the western Liaoning Province and adjacent parts of northeastern China, including exceptionally preserved feathered dinosaurs, early birds, and mammals. Most of these specimens are from the Cretaceous Period, including the famous Jehol Biota. However, in recent years many fossils have emerged from sites that are 30 million years earlier, from the Middle-Upper Jurassic Period, providing an exceptional window on life approximately 160 million years ago. A new paper published in latest issue of the Journal of Vertebrate Paleontology shows that several of these Jurassic sites are linked together by shared species and can be recognized as representing a single fossil fauna and flora, containing superbly preserved specimens of a diverse group of amphibian, mammal, and reptile species.

This fossil assemblage, newly named the Daohugou Biota after a village near one of the major localities in Inner Mongolia, China, dates from a time when many important vertebrate groups, including our own group, mammals, were undergoing evolutionary diversification. The Daohugou Biota makes an immense contribution to our understanding of vertebrate evolution during this period, with such notable creatures as the oldest known gliding mammal, another early mammal that may have swum with a beaver-like tail, the oldest dinosaurs preserved with feathers, and a pterosaur that represents an important transitional form between two major groups. As described by Dr. Corwin Sullivan, lead author of the study, "The Daohugou Biota gives us a look at a rarely glimpsed side of the Middle to Late Jurassic -- not a parade of galumphing giants, but an assemblage of quirky little creatures like feathered dinosaurs, pterosaurs with 'advanced' heads on 'primitive' bodies, and the Mesozoic equivalent of a flying squirrel."

Almost more impressive than the diversity of the biota is the preservation of many of the vertebrate specimens, including complete or nearly-complete skeletons associated with preserved soft tissues such as feathers, fur, skin or even, in some of the salamanders, external gills. Dr Yuan Wang, co-author of the study, explained, "The Daohugou amphibians are crucially important in the study of the phylogeny and early radiation of modern amphibian groups."

Dr. Paul Barrett, dinosaur researcher at the Natural History Museum, London, who was not involved with the study, commented, "Daohugou is proving to be one of the key sites for understanding the evolution of feathered dinosaurs, early mammals, and flying reptiles, due largely to the fantastic levels of preservation. Many of the fossils are stunning and offer vast amounts of information. There are only a handful of similar sites elsewhere in the world and this article represents the first comprehensive attempt to draw all of the relevant information together into a single benchmark paper." Because the Daohugou Biota and the much better studied Jehol Biota are similar in preservational mode and geographic location, but separated by tens of millions of years, they give palaeontologists an outstanding, even unique, opportunity to study changes in the fauna of this region over a significant span of geological time and an important period in vertebrate evolution. As Dr. Sullivan further remarked, "The Cretaceous feathered dinosaurs of northeastern China have been astonishing palaeontologists and the public for almost two decades now, and the Daohugou Biota preserves their Jurassic counterparts in the same region. As prequels go, it's pretty exciting."

Citation
Corwin Sullivan, Yuan Wang, David W. E. Hone, Yuanqing Wang, Xing Xu, Fucheng Zhang. The vertebrates of the Jurassic Daohugou Biota of northeastern China. Journal of Vertebrate Paleontology, 2014; 34 (2): 243 DOI: 10.1080/02724634.2013.787316

Friday, March 7, 2014

Interspecific aggression in garter snakes

The aquatic garter snake at Sibley Volcanic Regional Preserve, Oakland, CA. 
Photo credit: Sarah Stierch.
Aggressive behavior is used in many vertebrate communities to gain control of resources,  snakes, however, have been thought the exception. Some snake species use male-to-male combat for access to females, but this is intraspecies behavior.  Food partitioning usually thought to shape community structure of snake communities. A new study by Edgehouse and colleagues used two species of garter snakes at the Santa Lucia Preserve in Monterey Co. California. Both the common garter snake,Thamnophis sirtalis, the aquatic garter snake, a T. atratus and western terrestrial garter snake T. elegans coexist with their abundant, toxic prey  the California newt, Taricha torosa. At the study site,  Thamnophis sirtalis and T. atratus are aquatic and demonstrate independently evolved resistance to tetrodotoxin (TTX), a potent neurotoxin, found in the skin of the newt.

Edgehouse et al.  show that the common garter snake (Thamnophis sirtalis) and the aquatic garter snake (Thamnophis atratus) show a strong preference for amphibians and forces these snakes to exploit aquatic habitats. They investigate the aggressive behavior of T. sirtalis and the potential that this aggression displaces T. atratus from its preferred habitat. When individuals from either species were alone, they showed a complete preference for aquatic or near aquatic habitats. In contrast, when these species are together, T. sirtalis occupy the aquatic habitat and T. atratus occupy an area far removed from the water. They found Thamnophis sirtalis often physically force T. atratus from the aquatic habitat through repeated biting and other displays of aggression.

The spatial partitioning documented by the authors is likely a direct result of food availability and aggressive defense of the prey resource. The most abundant amphibian prey found in the snakes at the study site were California newt and the pacific treefrog.

Citation
Edgehouse M, Latta LC IV, Brodie ED III, Brodie ED Jr (2014) Interspecific Aggression and Habitat Partitioning in Garter Snakes. PLoS ONE 9(1): e86208. doi:10.1371/journal.pone.0086208

Sunday, March 2, 2014

Herpetofauna of the the Tay Yen Tu Nature Reserve, Vietnam

Rhynchophis boulengeri , one of the colubrids present at Tay Yen Tu. JCM

The Tay Yen Tu Nature Reserve is located in Bac Giang Province, about 100 km northeast of Hanoi, Vietnam and is situated in the western side of theYen Tu massif, which is the largest granitic formation in northeastern Vietnam. The main habitat of the area is evergreen broad-leaved tropical forest. The total area of the reserve is 16 ha and includes two non-contiguous sectors: the Thanh Son-Luc Son sector and the Khe Ro sector. The Thanh Son-Luc Son sector is centered on the 1,068 m high Mount Yen Tu, while the Khe Ro sector is about 886 m on Mount Da Bac. A comprehensive study on the biodiversity has not been conducted in the reserve to date, However, preliminary field research indicates the area supports a number of species of national or global conservation concern. Four new species have been discovered from Yen Tu Mountain in the last decade: Sphenomorphus cryptotis, Scincella devorator, Tylototriton vietnamensis and Odorrana yentuensis. Additionally, three new country records were recently reported from this nature reserve: Shinisaurus crocodilurus, Amphiesmoides ornaticepsm, and Rhacophorus maximus.  The discoveries of new reptiles and amphibians from Yen Tu Mountains underscore the unrealized biodiversity of northeastern Vietnam. Based on the results of recent field surveys Hetch et al. (2014) provide the first list of amphibians and reptiles recorded from Tay Yen Tu Nature Reserve.

A total of 76 species of amphibians and reptiles were recorded, including one caecilian, one newt, 34 species of anurans, 18 species of lizards, and 22 species of snakes. Thirty species are reported for the first time. Among the recorded species, five are currently known only from Vietnam. A high level of species diversity and endemism of the herpetofauna underscores the importance of biodiversity conservation in this nature reserve, which covers a major part of the remaining lowland evergreen forest in northeastern Vietnam.

Citation
Hecht, Vera L., Cuong T. Pham, Tao T. Nguyen, Truong Q. Nguyen, Michael Bonkowski, and Thomas Ziegler.  2014. First report on the herpetofauna of Tay Yen Tu Nature Reserve, northeastern Vietnam. Biodiversity Journal, 4 (4): 507–552.

Risk assessment for Burmese pythons in Everglades National Park

A large Burmese python, weighing 162 pounds and more than 15 feet 
long at the time of its capture in 2009. Caught alive in the Everglades, 
it had eaten an American alligator that measured about 6 feet in 
length. University of Florida researchers in the photo: Michael 
Rochford is holding the python's head, and Alex Wolf and Therese 
Walters are holding the python's body. Photo credit USGS.
The estimated tens of thousands of Burmese pythons now populating the Everglades present a low risk to people in the park, according to a new assessment by U.S. Geological Survey and National Park Service scientists.

The human risk assessment looked at five incidents that involved humans and Burmese pythons over a 10-year period in Everglades National Park. All five incidents involved pythons striking at biologists who were conducting research in flooded wetlands.

"Visitor and staff safety is always our highest priority at Everglades National Park," said Superintendent Dan Kimball. "Everglades, as many other national parks, draws many thousands of visitors for the opportunity to view the wildlife that live here in a natural setting. Our guidance to visitors with respect to Burmese pythons is the same as for our native wildlife -- please maintain a safe distance and don't harass the wildlife. With respect to controlling Burmese pythons, we are working diligently with our state, federal, tribal, and local partners to manage this invasive species and educate the public on the importance of not letting invasive species loose in the wild."

Although there have been numerous bites to people provoking Burmese pythons by attempting to capture or kill the snakes, this study examined only unprovoked strikes directed at people.

"The strikes did not appear to be defensive, but were more likely were associated with aborted feeding behavior," said USGS wildlife biologist and herpetologist Bob Reed, the lead author of the study. "Pythons usually direct defensive strikes at the front of a person, not from the side or rear, as all of these strikes were. Additionally, Burmese pythons rely on being secretive and evading detection as their primary means of avoiding interactions with people, and typically don't strike until provoked."

The biologists did not detect any of the snakes before the strikes occurred, making it even more likely that the attacks were related to feeding and not defense, Reed noted. Two of the attacks resulted in very minor injuries from the pythons' teeth and none involved constriction.

Reed and his co-author, retired Everglades National Park scientist Skip Snow, consider the attacks as cases of mistaken identity. In four of five cases the python was small compared to the size of the person, which resulted in the snake likely aborting the attack upon realizing the large size of its prey. Aborting strikes before actual bites with the possible prey indicates that pythons may be able to assess the size of the prey mid-strike and adjust accordingly, the study said.

Although the pythons' threat to people is low, previous studies have shown that this invasive snake species is having a negative effect on many of the native mammals in the South Florida Everglades. One study suggests the population of raccoons, opossums, and bobcats have declined significantly in the regions of Everglades National Park where pythons have been established the longest.

More than one million people visit Everglades National Park every year, often traveling along hiking and canoeing trails where Burmese pythons have been spotted or captured. Despite this close interaction, the study noted that none of the reported incidents involved a park visitor. All of the incidents were directed at biologists moving through remote and flooded areas of the park.

"As people wade through shallow water, they produce ripples that move ahead of them, and these pressure waves may be detectable to a motionless snake in ambush posture," said Reed. "We speculate that detecting these changes in water pressure may alert a python that an animal is approaching, perhaps priming it to strike immediately when a potential prey item is detected."

Burmese pythons became established in Florida several decades ago as a result of the international pet trade. The largest snakes removed from the Everglades have exceeded 18 feet and 150 pounds. Snakes of this size are capable of ingesting large prey like deer and alligators.

This human risk assessment concluded that although the risk of an unprovoked attack by a Burmese python in Everglades National Park is low, it is not non-existent. Available evidence from captive snakes suggests that even those strikes that result from cases of mistaken identity or defensive behavior may still result in constriction, which can prove fatal to people when a large python or a small human is involved.

The study focused only on the risk associated with Burmese pythons, but did not address other invasive constrictor species, such as the Northern African python, which is also known as the African Rock python, which are also known to be established and breeding in South Florida outside of Everglades National Park. USGS scientists continue to work with partners to better understand the impacts on invasive reptiles in the Everglades, help reduce their spread into new areas and help prevent new species from becoming established.

Citation
RN Reed, RW Snow. 2014 Assessing risks to humans from invasive Burmese pythons in Everglades National Park, Florida, USA. Wildlife Society Bulletin, DOI: 10.1002/wsb.413

Tuesday, February 25, 2014

A new systematic arrangement for skinks

One-quarter of all lizards are skinks, and they have been traditionally placed in the single family  Scincidae. 1,579 species of skinks are known and they compose the largest group of saurians.  Other large lizard families, such as Gekkonidae and Iguanidae have been partitioned into multiple families , based mainly on evidence from molecular phylogenies. Subfamilies and informal suprageneric groups have been used for skinks, defined by morphological traits and supported increasingly by molecular phylogenies.

In a new paper S. Blair Hedges morphological diagnoses all nine families of skinks (Scincomorpha).

Recently, a seven-family classification for skinks was proposed to replace that largely informal classification, create more manageable taxa, and facilitate systematic research on skinks.

Representatives of 125 (84%) of the 154 genera of skinks are available in the public sequence databases and have been placed in molecular phylogenies that support the recognition of these families. However, two other molecular clades with species that have long been considered distinctive morphologically belong to two new families described in this paper:  Ristellidae and Ateuchosauridae.

The Ateuchosauridae is a family of lygosomoid skink possessing diagnostic characters: Meckel's groove not recorded; parietals small or absent and nuchals absent ; the outer preanal scales overlap the inner preanals; scales on digits in two rows; the iris is nearly as dark as the pupil. Also, the frontoparietals are paired; the frontal is long and constricted, longer than frontoparietals plus interparietal; and the prefrontals are small and separated. Ateuchosauridae is distributed in Japan (Ryukyu Archipelago), southeastern China, and northeastern Vietnam.The family includes the Chinese forest skin shown below.


The Ristellidae contains the genus Lankascincus  (10 sp.) and Ristella Gray (4 sp.). This is a family of lygosomoid skink with: more than 11 premaxillary teeth; Meckel's groove is completely obliterated (closed) by the overlapping and fusion of dentary; parietals meet behind interparietal; parietal bordered along its posterior edge by two or more temporals; nuchals usually absent (undifferentiated); outer preanal scales overlap inner preanals; scales on dorsal surface of fourth toe mostly in a single row; iris variable. Ristellidae is distributed in southern India and Sri Lanka.  The family includes the genus Lankascincus shown below.


The family Acontidae  holds 26 species of African and Madagascar skinks. Including the Acontia sp. shown below.



The family Egerniidae holds 58 species in nine genera including the Tribolonotus shown below. The family occurs in Australia and Australasia



The family Eugongylidae  holds 418 species in 37 genera. including the Lampropholis guichenoti shown below. The family occurs in Australia and Australasia



The family Lygosomidae 52 species including the Mochlus guineensis  shown below, the family is Asian



The family Mabuyidae has 190 species and is Neotropical in distribution. Copeoglossum aurea shown blow is a member of this family.

The family Sphenomorphidae has 546 species and has an Asian and Australian distribution. It includes the Sphenomorphus sabanus from Borneo below.

The family Scincidae contains 273 species that are distributed from Africa and Asia to the Western Hemisphere and includes Plestiodon fasciatus shown below.


Citation
Hedges SB 2014. The high-level classification of skinks (Reptilia, Squamata, Scincomorpha). Zootaxa 3765:317-338.

Sunday, February 23, 2014

The amphibians and reptiles of Mindo, an Ecuadorian cloud forest ecosystem



If you have not yet found the Tropical Herping web site, I would encourage you to visit it. Alejandro Arteaga and colleagues have done an outstanding job building this elegant and information filled website. What follows is a short article from the site and some  photography. 

By Alejandro Arteaga, Lucas Bustamante and Juan Guayasamin

After four years of extensive fieldwork, the research team at Tropical Herping unveiled the richest community of amphibians and reptiles in any cloud forest locality above 1000 m. The team found an array of 101 species, and the results were published in the book The Amphibians and Reptiles of Mindo. But more than just the numbers, it is the value of the species what matters. The array includes some of the rarest and most bizarre amphibians and reptiles on earth, along with many that cannot be found outside Ecuador, and many others that are on the brink of extinction.

In the study area, Mindo, there are 10 species of glassfrogs. One of these is new to science and was not included in the book. This makes Mindo the best place in the world to see these marvelous creatures, which are famous for their partial or total ventral transparency. As it turns out, a visitor may spot five species in just one cloud forest stream.

There are five species of vipers and one is probably new. Among the included species, the Osborne's Lancehead (Bothrops osbornei) and the Spotted Lancehead (Bothrops punctatus) are believed to be Ecuador's rarest species of vipers and also the most venomous. The Ecuadorian Toadhead (Bothrocophias campbelli) is also extremely difficult to spot, but if you are planning to encounter one, Mindo is the place to go.
The Osborne's Lancehead (Bothrops osbornei) is one of the
 rarest and most enigmatic vipers in the world. Less than 20 
individuals have been seen throughout the course of history.
 © 2014 Tropical Herping
One single feature sets the Pinocchio Rainfrog (Pristimantis
appendiculatus) apart from the other nearly 530 species of
amphibians in Ecuador.It has an exaggeratedly elongated
 fleshy tubercle at the tip of its snout. © 2014 Tropical Herping.
With 27 species of rainfrogs, Mindo is the single most species rich locality in the world when it comes to this notoriously varied group of frogs. Not only is the variety of rainfrogs impressive, but also how little is known about them. In fact, one species, the Mindo Rainfrog (Pristimantis mindo), is described in the book as a species new to science. Besides their enigmatic variety, another amazing feature of rainfrogs is their lack of a tadpole stage. Instead, the adults lay terrestrial eggs that later hatch into miniature versions of the adults. Mindo is home to seven species of arboreal lizards, the anoles. One of these, the famous Pinocchio Anole (Anolis proboscis), was thought to be extinct for nearly fifty years. Now that is has been rediscovered, researchers and tourists around the world are visiting the valley of Mindo to study and admire the lizard.

Finally, from the 101 Mindoan amphibians and reptiles, 31 occur only in Ecuador, 72 are threatened with extinction, and two of them are already extinct. 

Ecuador's most wanted: the Pinocchio Anole (Anolis proboscis). 
This lizards was thought to be extinct for nearly fifty years, 
and still after its rediscovery in 2005, it remains hard to locate.
The concentration of endangered species is one of the highest in the continent. What is at stake is one of the most fragile, rare and fascinating communities of amphibians and reptiles in the world. However, there is still a lot you can do to help conserve this natural heritage, from supporting local lodges, reserves and research institutions to spreading the word about the marvelous amphibians and reptiles of the cloud forest.

Saturday, February 22, 2014

Tree climbing crocs

An American alligator perches in a 
tree  in the Pearl River Delta, Mississippi. 
Photo credit: Kristine Gingras, courtesy 
of  University of Tennessee
Two species of paleo crocodilians (Mekosuchus inexpectatus  and Trilophosuchus rackhami) have been hypothesized to have been arboreal, they share a  small body size and have a lighter build than most other crocs and have been commonly referred to as "drop crocs."

Now, Vladimir Dinets and colleagues (2014) review the evidence that living species of crocodilians can and do climb into trees, a behavior overlooked by science until now.

People around the world have observed and photographed the arboreal abilities of many crocodilian species, but herpetologists hadn’t studied the behavior. Now, research documented tree-climbing Australian freshwater crocodiles, American crocodiles, Central African slender-snouted crocodiles and Nile crocodiles. The paper also presented anecdotal reports of many other croc species taking to the trees.

The crocs weren’t just clambering onto easily reached low branches. The animals could climb vertical trunks. Sometimes climbing all the way to the trees’ crown.

Most of the tree-climbers  were young and still relatively small, two meters (6.5 feet) or less in length. The animals may have been climbing the trees to bask in the sun, since the areas where the animals were observed in trees often lacked other suitable sun bathing locations, noted the study’s authors.

The slender-snouted crocodile of central Africa is quite adept at arboreal behavior. They  roosted on branches both night and day. One specimen climbed though a tangle of branches to rest on a branch five meters from the river bank and four meters above the water.

With some of the species examined the ability to climb decreases with increasing size and mass. Hatchlings are lightweight and can even climb vertical brickwork . In the  wild, Australian freshwater crocodiles frequently climb into low branches above the water, either by climbing directly onto the tree close to the water, or by climbing onto the tree from the bank and then along a branch.

The authors note that the ability to climb vertically reflects crocodilians’  spectacular agility on land and their ability to pull the body along an angled surface. And, that the degree of arboreality of extinct crocodilians and many other Archosaurian taxa cannot always be ascertained from fossil material. Any small, highly terrestrial crocodilian, such as the recently extinct Trilophosuchus rackhami could have been be arboreal to some extent.

Citation
Dinets V, Britton A, Shirley M. 2014. Climbing behaviour in extant crocodiles. Herpetological Notes 7:3-7.

Friday, February 21, 2014

Global sea turtle harvest exceeds 42,000 per year

A new study has found that 42 countries or territories around the world permit the harvest of marine turtles -- and estimates that more than 42,000 turtles are caught each year by these fisheries.  The research, carried out by Blue Ventures Conservation and staff at the University of Exeter's Centre for Ecology and Conservation, is the first to comprehensively review the number of turtles currently taken within the law and assess how this compares to other global threats to the creatures.

All seven marine turtle species are currently listed on the IUCN Red List of Threatened Species.
Frances Humber of Blue Ventures and a PhD student at the University of Exeter, who led the research, said: "This is the first study to comprehensively review the legal take of turtles in recent years, and allows us to assess the relative fisheries threats to this group of species. Despite increased national and international protection of marine turtles, direct legal take remains a major source of mortality. However, it is likely that a fraction of current marine turtle mortality take is legal, with greater threats from illegal fisheries and bycatch."

The first marine turtle harvest legislation was instigated in Bermuda in 1620 to protect "so excellent a fishe" and prohibited taking any turtle "under eighteen inches in the breadth or diameter."

But large scale commercial taking of turtles continued all over the world for centuries, with global capture peaking at over 17,000 tonnes in the late 1960s. For example, during the peak of Mexico's sea turtle exploitation in 1968 it is estimated that the national take was over 380,000 turtles.

Increased conservation awareness at an international scale has led to greater protection of marine turtles, with 178 countries now signed up to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) restricting the international trade of turtle products.

The direct take of turtles has continued legally in many regions and countries, often for traditional coastal communities to support themselves or small-scale fisheries supplying local markets with meat, and sometimes shell. The fisheries are an important source of finance, protein and cultural identity, but information can be scarce on their status -- despite often being listed as one of the major threats to turtle populations.

The researchers collated data for all seven species of marine turtles from over 500 publications and 150 in-country experts.

They estimate that currently more than 42,000 marine turtles are caught each year legally, of which over 80% are green turtles. Legal fisheries are concentrated in the wider Caribbean region, including several of the UKs Overseas Territories, and the Indo-Pacific region, with Papua New Guinea, Nicaragua and Australia together accounting for almost three quarters of the total.

The data indicates that since the 1980s more than 2 million turtles have been caught, although current levels are less than 60% of those in the 1980s.

Bycatch -- the unwanted fish and other marine creatures trapped by commercial fishing nets during fishing for a different species -- is thought to be a far higher cause of death for marine turtles, likely running into hundreds of thousands each year.

Illegal fishing also continues to be a major cause of mortality, with the researchers estimating a minimum of 65,000 turtles taken from Mexico alone since the year 2000. The scale of global illegal capture is likely to be severely under reported due to the difficulties collecting information on such an activity.

Dr Annette Broderick, of the Centre for Ecology and Conservation at the University of Exeter's Penryn Campus in Cornwall, added: "We were surprised to find that there are 42 countries with no legislation in place that prohibits the harvest of marine turtles, although for many of these countries these harvests provide important sources of protein or income. It is however important to ensure that these fisheries are operating at a sustainable level."

Citation
Humber, F., Godley, B. J., Broderick, A. C. (2014), So excellent a fishe: a global overview of legal marine turtle fisheries. Diversity and Distributions. doi: 10.1111/ddi.12183

Tuesday, February 18, 2014

Dusky sea snake (Aipysurus fuscus) may disappear into a hybridization swarm

A University of Adelaide-led project has found that the endangered dusky sea snake (Aipysurus fuscus) is even more at risk of extinction than thought because of surprising cross-species hybridization.

This follows a pattern of unexplained drastically declining populations of sea snakes in the reefs of the Timor Sea in north-west Australia over the past 15 years.

Published in the journal Biological Conservation, the study found that at one of only two remaining coral reefs where they are still found, dusky sea snakes had hybridised almost completely with the closely related olive sea snake.

"Genetically-pure duskies might now only be found at one remaining reef ̶ the isolated Scott Reef, an area of about 160 square kilometres in the Timor Sea, about 300km north of the Kimberley coast," says project leader and lead author Dr Kate Sanders. "Such loss of biodiversity because of hybridisation is an important conservation problem and there are dire implications for the conservation status of the dusky sea snake."
Referred to as the "miners' canary" of coral reef health, sea snakes bear live young rather than eggs and are the only fully aquatic reptile.

The sea snakes are Australian native animals. They evolved in Australia from a land snake ancestor and have been highly successful in adapting to a marine environment. There are 62 species, found mostly in Australia and South-East Asia with the greatest diversity previously on the isolated reefs of the Timor Sea.
"Five Timor Sea reefs previously supported the highest diversity and abundance of sea snakes in the world, but the largest reef, Ashmore, has lost all of its nine resident species over the past 15 years," says Dr Sanders.

In this study the researchers collected and released sea snakes on the remaining four reefs by snorkeling with nets. They used DNA fingerprinting to show that endangered dusky sea snakes frequently interbreed with closely related olive sea snakes which are much more locally abundant and wide ranging.

"These reefs are largely undisturbed by fishing and habitats have remained intact so we had assumed the populations would have been stable," Dr Sanders says. "But when we surveyed at Hibernia Reef, we were very surprised to find interbreeding at that level, with the two species almost completely hybridised to produce a so-called 'hybrid swarm'.

"Hibernia is one of only two reefs that have supported dusky sea snakes following their extinction at Ashmore Reef. Now it seems that they are on the path of genetic extinction at Hibernia too. Olive and dusky sea snakes diverged about 500,000 years ago. The loss of biodiversity through this 'reverse speciation' is of particular concern because we don't know what has driven this change on our reefs. It certainly requires close monitoring and further investigation."

Citation
Kate L. Sanders, Arne R. Rasmussen, Michael L. Guinea, 2004. High rates of hybridisation reveal fragile reproductive barriers between endangered Australian sea snakes, Biological Conservation, 171, March 2014, Pages 200-208, ISSN 0006-3207, dx.doi.org/10.1016/j.biocon.2014.01.013.


Monday, February 17, 2014

Suizo Report--CM12 "Jerry" and CM17

02/17/13  Howdy Suizo List,

It has been so long since I've done a Suizo Report that I've forgotten how it's done. But we'll give it our best shot.

Probably less than half of this list will ever remember the days before digital photography. And if you DO remember, when was the last time you had your 35mm slides on a light table?

With me, it was two weeks ago. I was looking for a few images to scan for an upcoming presentation. What I was after were a few images of Gila Monsters and Tortoises from the Suizos. It so happens that with my 35mm slides for the Suizos, I also have Black-tailed Rattlesnakes, Lyresnakes, and people in that particular binder. Everything image in this binder is carefully labeled, and set up in such fashion that all the animals are grouped according to species, in chronological order.

On the first page of this binder, I about fell out of my chair when I looked at the third black-tailed rattlesnake we ever found on Iron Mine Hill. By golly, it was Jerry, AKA "CM12."  We  could make a long story out of  seeing  Jerry 12 years after  putting a transmitter  in him, but none of us has the kind of time that takes. We'll let the images do the talking for a minute:

Image 1, CM12, image taken 9 April 2000. Note the fact that he is an adult snake in this image. It is a shame his rattles are broken. But we can see that the first few segments are wide and straight. This is usually an indication of an older adult snake, but again, the broken string does not allow for that. My notes are pretty brief, they only indicate that a 36 inch long adult blacktail was found on NW Iron Mine Hill on this evening. (We did not process snakes back then).


Image 2, CM12, image taken 26 March 2012. This was the day after he was captured for a transmitter. This is very close to 12 years after the first encounter. Note how every pattern on the head is exactly identical 12 years later, not to mention the body pattern. I know that Jeff and Melissa will be on these first two images like scum on a pond--same snake, eh youse two? 8-)


Image 3, CM12, image taken by Marty Feldner, 15 February 2014. He's still going strong, nearly 14 years later.

So, how old is Jerry? 20 years? Sure--he could easily be 20. And he could be older than that. I'm always interested in hearing about how long snakes, as well as herps in general, can last in the wild. Feel free to lay any similar incidences on me.

The fourth image is of our female CM17, "Ms. Gus." Much to our dismay, her transmitter stopped working in early January. (Three months early). There is NOTHING more frustrating than a dead signal when you can actually see the animal--but can't get to it. She was wedged deep in a crevice at the time, crowbars and dynamite MAY have gotten her out--but not alive. All we could do is watch and wait, and hope we could find her out basking before egress sent her down the path of being lost forever. On the morning of 15 February, I noted that her rear flank was about 25mm deep in her crevice. She was close enough to possibly grab, but I decided to wait, and drag Marty back with me in the afternoon. This with the hope that the warm weather would cause her to come out further.


At 1600, Marty and I stood before her crevice again. While she did move out any further, neither did she back in. She was exactly as viewed earlier that morning.

There was a somewhat tense discussion that followed, the gist of which was if we tried to grab her and blew it, she would be long gone. If we made the grab, there was no turning back. If we had to break her in half getting her out with lawn-mower starting-like yanks--that is what we would do. Marty eased the situation be moving a small boulder that was blocking the forced egress that was intended. I hooked the tail out, Marty got the rear with tongs, and she just came right on out!

My last Suizo Report, ancient history ago, dealt with Gus and Ms. Gus. Having lost Gus to a predation event was bad enough. To lose Ms. Gus on account of a failed transmitter was almost a death knell to the study. We saw the pair mating, and we saw Ms. Gus have the kids. This is the year when we track Ms. Gus AFTER parturition. Will she drop kids again this year? Up until two days ago, we were not sure we would know that. And while anything can still happen between now and August, we at least can proceed with confidence that we have a fighting chance of finding out.

As the image shows, she has recovered nicely from her ordeal of last August.

Holohil still make the best transmitters out there. And they are very nice people to do business with. But there is no way they can ever feel our angst when the batteries die prematurely in their units. A new transmitter can never replace a lost child!

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.
Best to all, roger

Tuesday, February 11, 2014

The Odontobatrachidae, a new family of West African Frogs

Berlin scientists discover new frog family in West Africa
Dr. Gesine Steiner Pressestelle, Museum für Naturkunde - Leibniz-Institut für Evolutions- und Biodiversitätsforschung

To the left. Top. Odontobatrachus natator: one 
species of the new frog family. Photo: Mark-Oliver 
Rödel. Bottom. Scan of the skull: the unusual 
teeth are one unique anatomic character of the
 new frog family Scan: Michael F. Barej.

In Africa morphologically very similar frogs live along fast flowing rainforest rivers and at waterfalls, the Torrent Frogs. While studying the phylogeny of these frogs, scientists from the Berlin Natural History Museum and their colleagues from Switzerland came across a scientific sensation. The West African species apparently were not closer related to the other African species. In fact they represent a family already separated from other frog groups since the Cretaceous, the time when dinosaurs dominated life on Earth.

Many new frog species are still discovered and scientifically described each year, in particular from the tropics. Usually not much is known about the biology and phylogeny of these species. However, the distribution and relatedness of species may deliver important insights to scientist concerning the history of our planet, such as e.g. climate change and the evolution of particular ecosystems. Therefore scientists from the Berlin Museum of Natural History, with their colleagues from Switzerland, aimed at uncovering the phylogeny of African torrent frogs.

These morphologically very similar frogs are specialized on rapidly flowing rainforest streams and waterfalls in West, Central and East Africa. The researchers applied genetic and anatomic methods in their study and were thrilled when they discovered that the West African species apparently were not at all related to the species from the other areas. Whereas the discovery of new frog species is not unusual, even the identification of a new genus is already very rare. Thus Michael Barej, the first author of the study, stated, that to him it was like “hitting the jackpot. I needed to cool down when we discovered that we might have discovered a new frog family. It felt simply too unreal.”

However, the scientists could indeed show that the West African torrent frogs split from other frogs already in the Cretaceous, the time of dinosaurs. Apart from genetic differences and with the aid of computer tomography Michael Barej and his colleagues also discovered various unique anatomic characters.

Consequently they erected a new frog family, the Odontobatrachidae, for these West African frogs, just published in the scientific journal Frontiers in Zoology. The scientific name of the new family stems from the Greek words for tooth and frog, and is based on an anatomic uniqueness. The frogs of the new family are characterized by long and bent teeth in the upper jaw and massive fangs in the lower jaw, a very unusual setting for frogs. It is not yet clear what these teeth are used for. Maybe the frogs feed on other frogs, as it might be indicated by the discovery of a small frog skeleton in the stomach of one of the larger individuals.
The discovery of this new frog family is also of importance to the conservation of tropical biodiversity. The “tooth frogs” only occur in small forest remnants in the West African countries of Guinea, Sierra Leone, Liberia and Ivory Coast. Mark-Oliver Rödel from the Berlin Museum of Natural History emphasizes that this discovery further underlines the uniqueness of the West African biodiversity hotspot and he hopes that the new family may be helpful in future efforts to protect these forests, not only for frogs.

Citation
Barej, M.F., A. Schmitz, R. Günther, S.P. Loader, K. Mahlow & M.-O. Rödel (2014): The first endemic West African vertebrate family – a new anuran family highlighting the uniqueness of the Upper Guinean biodiversity hotspot. – Frontiers in Zoology 11:8 doi:10.1186/1742-9994-11-8.



Monday, February 10, 2014

Two fossorial snakes and the prairie chicken vs developers in Kansas

Snakes and prairie chickens pit development against species preservation in Kansas
February 9
BY BRAD COOPER
The Kansas City Star
The red-bellied snake, Storeria occipitomaculata

TOPEKA — Barely a half-foot long without a drop of venom, the redbelly snake hardly seems  a threat. Unless you’re a developer or public official in Johnson County.

Listed by Kansas as a threatened species, the reddish brown reptile with the orange belly is complicating growth in Johnson County.

County leaders are reluctant to dip into taxpayers’ wallets to preserve a snake habitat disrupted by new development. So they are waging a battle with the seldom-seen snake that’s not much longer than a typical worm.

They’re asking the Kansas Legislature to remove the redbelly and the comparable smooth earth snake from the state’s threatened species list.

That sets up a familiar debate pitting the cost-saving demands of development against species preservation that some see as environmental overreach.

“You’ve got an economy that’s struggling to recover, and this adds costs to every development and every business that wants to build,” said Doug Mays, a lobbyist for the city of Olathe. “That’s a problem.”

The debate over species protection grows more pronounced in the Kansas Legislature as powerful utility and agricultural interests press lawmakers to relieve the financial burden of complying with more regulations.

There have been fights to limit the state’s endangered species law by critics who say it protects animals that may be rare in Kansas but remain abundant elsewhere.

Lawmakers are also considering a measure to block the federal government from protecting the lesser prairie chicken in Kansas.

“There appears to be a major movement afoot to try and undermine all the protections available to threatened and endangered species,” said Ron Klataske, executive director of Audubon of Kansas.

He called it a “war on wildlife.”

Businesses say they want the state to enforce the endangered species law in a way that  allows a different balance between conservation and economics.

“We want to be good stewards,” said Aaron Popelka, lobbyist for the Kansas Livestock Association. “The accusation that we’re trying to undermine species conservation is completely off base.”

Some lawmakers say the issue leaves them torn because it pits the economy against the environment.

“That’s a hard one,” said Rep. Ed Trimmer, a Winfield Democrat who sits on the House Natural Resources Committee.

“What we really have to be concerned about is if it is a linchpin species, if it’s one that’s really going to disturb the balance of the ecosystem.”

The fight over species started this year when Secretary of State Kris Kobach urged lawmakers to pass a bill barring the federal government from protecting the lesser prairie chicken in Kansas.

Kobach wants Kansas to assert sovereignty rights challenging what rules the federal government can impose on the state.

Federal wildlife officials say there has never been a case where a state nullified enforcement of the federal Endangered Species Act. Montana tried to nullify the federal species protection law in 2011, but the bill died after critics said it would cost the state roughly $1 billion in federal funds.

The U.S. Fish and Wildlife Service is deciding whether to place the bird on the federal endangered species list because development and farmland are consuming its habitat.

The bird’s geographical territory, including southwest Kansas and parts of Texas, Colorado, Oklahoma and New Mexico, has been reduced by 86 percent since the mid-1800s.

Threats to the bird include wind farms, oil and gas production, herbicides, drought and livestock grazing.

Kansas Electric Cooperatives and the Kansas Farm Bureau back the bill.

Designating the bird as endangered or threatened could stymie the state’s wind industry by limiting placement of wind turbines. It also could double the cost of building power transmission lines.

Gov. Sam Brownback recently sent a letter to the Fish and Wildlife Service asking that the bird not be listed as endangered. Such a designation would hurt the state’s agriculture and energy sectors, he said, and the state is ready to challenge the federal agency in court.

Last year, utility and agriculture interests backed a Kansas bill limiting the species placed on the state endangered list.

That bill stemmed from construction of a feedlot in southwest Kansas that would have encroached on the longnose snake, which was on the state’s endangered list.

Ultimately the feedlot came up with an alternative plan and avoided paying as much as $50,000 for preserving the snake’s habitat.

As with the case of the snakes in Johnson County, the longnose snake is rare in Kansas because the state is on the outer edge of its geographical home. The longnose snake is not threatened nationally.

The Kansas Livestock Association pushed the bill, claiming Kansas regulated the environment more stringently than the federal government.

The bill’s critics argued that it would eviscerate the state’s endangered species law.

Kansas Wildlife and Parks Secretary Robin Jennison said the bill would have slashed the state’s endangered list of 60 animals by nearly half.

He also pushed back against charges the state leaned in favor of environmental interests.

From 2008 to 2012, the agency reviewed 9,127 projects. Just 50 of them led to environmental restoration.

The department’s enforcement of endangered species rules, he told lawmakers, is “hardly heavy-handed.”

In Johnson County, officials blame the redbelly snake and the smooth earth snake for driving up the cost of water and sewer lines.

Olathe spent $50,000 to preserve habitat for the snakes when it expanded its Cedar Creek sewer plant for $46 million.

Johnson County spent $95,000 mitigating for the snakes on two sewer projects totaling $30 million.

Johnson County WaterOne is spending $130,000 in habitat preservation for a $67 million water line project serving the southeastern part of the county.

“Granted, it sounds like it’s not much, but it’s still unjustified dollars,” WaterOne lobbyist Darci Meese told lawmakers. “It would be difficult for the public to understand in most cases why we’re trying to create a habitat for a snake no one can seem to find.”

The redbelly and smooth earth snakes live largely unseen in wooded areas under rocks, leaves and logs.

From 2009 through 2013, the Kansas Biological Survey recorded reports of two smooth earth snakes in Johnson County and five others in Wyandotte and Leavenworth counties. One redbelly snake was reported in Leavenworth.

A redbelly snake has never been reported in Wyandotte or Johnson counties, although a suitable habitat exists there, said Bill Busby, associate scientist for the biological survey.

The Brownback administration opposes using legislation to take the snakes off the list. Jennison said there is protocol for scientifically evaluating whether animals should be on the list.

The state has received petitions seeking to remove nine species, including requests from Olathe, WaterOne and Johnson County to remove the snakes.

Biologists will study the petitions and make a recommendation to the parks and wildlife secretary.

Jennison urged legislators not to micromanage the endangered species list.

“We have thrown science out the window,” he said, “if we make the act of listing our species a political decision.”

Wednesday, February 5, 2014

A new record size for south Florida Pythons


News outlets are reporting a large  Burmese python discovered in the Florida Everglades is the largest found to date in southern Florida. The past record, for the longest python found in the area 17 ft, 7 inches. It was found in May 2012 and was a gravid female containing 87 eggs, and weighed about 164 lbs. The female snake discovered yesterday (02/04/2014) was found by Bobby Hill, the python control officer for the South Florida Water Management District on Tuesday. The Florida Fish and Wild Conservation Commission reported that today's snake measured 18 ft 8 ins and weighed 128 lbs.

Tuesday, February 4, 2014

The Skink and the Crab - life in a Western Australian Salt Marsh


Photo credit R. Lloyd.
The striped slinks of the genus Ctenotus are the most diverse lizard clade of Australia with more than 100 known species. The Airlie Island Ctenotus is a dark olive-grey to light brown skink with a 64–69 mm body. Until recently it was known from the island and two mainland location.

The skink is threatened by buffel grass, an invasive plant that results in the loss of skink habitat. The weed has been successfully controlled on Airlie Island however, it is unknown whether it has been eradicated and if there is a future risk of habitat loss is on the mainland.

Human disturbance is also a threat to the skink with 3 ha or about 12% of the skink's range cleared of vegetation on Airlie Island  for the development of oil and gas processing facilities.

Many of the mainland skink populations are located close to the shoreline, and it is likely that rising sea levels and floods associated with climate change could impact the species.

Somaweera and Lloyd. (2014) conducted surveys for the skink and found populations along the northwestern coast, which appear to be highly restricted to specific habitats, primarily salt marsh communities adjacent to mangroves where lizards use crab holes for refugia. Genetic analysis of mitochondrial DNA showed very little variation between populations, suggesting a single widespread population or recent radiation.

Ctenotus angusticeps was previously recorded in most habitat types on Airlie Island, such as tussock grasslands and Acacia coriacea shrubland with coastal Spinifex  however then authors focused their survey efforts in salt marsh communities because of observations previously reported in the literature.  The landward fringe of mangroves are numerous and patchy along the northwestern coast. These are quite different from the habitats on Airlie Island and suggest the salt marsh communities are the ancestral habitat for this species, with the island population secondarily adapting to the habitat now present on the island. The authors observations confirm the Airlie Island striped skink is very habitat specific and they report it to be highly dependent on crab holes.

Wherever  the skink was found, crab holes of varying sizes were present and these were used by skinks to evading  attempts at capture. Initially, when adult lizards were observed they hid at the base of low vegetation, followed by retreating down a hidden hole among the samphire and marine couch grass. Juvenile
lizards usually relied on the protective cover of the vegetation to avoid capture, often taking refuge in the dense tussocks of marine couch grass. Both adults and juveniles were sometimes observed to retreat into samphire vegetation, sometimes up to 30 cm above the ground.

This species seems to be opportunistic in selecting retreat sites upon pursuit. To test whether lizards would use crab holes even in the absence of perceived threat the authors used a non-toxic fluorescent powder to track their movements. Two adult C. angusticeps caught early in the day were dipped in the ‘powder’ and
released. The next morning they tracked their movements from the previous day to separate crab holes where the lizards spent the night demonstrating the lizards use crab holes by choice.

The authors also report seeing lizards enter crab holes during rising tides and apparently remained in the burrows until the tide had receded - presumably surviving in air pockets in the burrows. The author's suggest this needs further investigation.

The  high frequency of crab hole usage by lizards in the salt marsh communities leads the authors to suggest crabs holes are an essential requirement for this species. Mangrove crabs could be considered  ecosystem engineers, a group of animals that physically create, maintain and modify their environment. Hence the spatial distribution and abundance of species that use these holes could vary with the distribution of the particular species of crabs.

Citation (on-line, no publisher given)
Somaweera MBR. R. Lloyd R. 2014. Status of the Airlie Island Ctenotus, Ctenotus angusticeps (Lacertilia: Scincidae), with notes on distribution, habitat and genetic variation.