Thursday, November 16, 2017

River valleys and snake genetics

Pituophis catenifer sayi
The genetic population structure of snakes can vary markedly based on a number of intrinsic and extrinsic factors. Some snake species show only very modest levels of subdivision or none at all, while others show a high degree of differentiation over small spatial scales. The variation among species is likely due to a wide variety of biological traits (e.g. natal philopatry, home range size, specific habitat requirements), as well as the ability of individuals to disperse. Dispersal and associated gene flow among breeding groups may also be influenced by extrinsic factors such as natural or man-made barriers.  It is only recently that snake populations at range peripheries or in extreme environments have become the focus of conservation genetics studies. Conservation challenges may be exacerbated for populations at range peripheries, where extreme environments and naturally sparse distributions interact with anthropogenic activities to generate additional risk factors.

Snake populations at the northern limits of their range face ecological challenges that may affect dispersal, gene flow, and ultimately genetic population structure. For example, snakes at higher latitudes in North America and Eurasia rely heavily on a limited number of suitable hibernacula to survive harsh winters, and they often exhibit high fidelity to these sites (e.g. Elaphe obsoleta obsoleta, Gloydius halys). In addition, landscapes containing both suitable hibernacula and summer habitat for northern snakes may be patchily distributed at range margins, a situation that is exacerbated by human activities that cause habitat loss and fragmentation. Thus, gene flow may only occur among northern snake populations when individuals travel long distances away from dens to breed; however, successful dispersal may be uncommon, resulting in highly subdivided populations. Interestingly, several recent studies have shown that some snake species have much larger home ranges and travel long distances from hibernacula at northern range limits. In principle, these behavioral traits may partially counteract the barriers to gene flow discussed above. Understanding this situation is of key interest in Canada, where a variety of North American snakes, some of which are of conservation concern, reach their northern range limits.

On the North American Great Plains, several snake species reach their northern range limit where they rely on sparsely distributed hibernacula located in major river valleys. Independent colonization histories for the river valleys and barriers to gene flow caused by the lack of suitable habitat between them may have produced genetically differentiated snake populations. In a recent paper Somers et al (2017) test this hypothesis, using 10 microsatellite loci to examine the population structure of two species of conservation concern in Canada: the eastern yellow-bellied racer (Coluber constrictor flaviventris) and bullsnake (Pituophis catenifer sayi) in 3 major river valleys in southern Saskatchewan. Fixation indices (FST) showed that populations in river valleys were significantly differentiated for both species (racers, FST = 0.096, P = 0.001; bullsnakes FST = 0.045–0.157, P = 0.001). Bayesian assignment (STRUCTURE) and ordination (DAPC) strongly supported genetically differentiated groups in the geographically distinct river valleys. Finer-scale subdivision of populations within river valleys was not apparent based on their data, but is a topic that should be investigated further. The findings highlight the importance of major river valleys for snakes at the northern extent of their ranges and raise the possibility that populations in each river valley may warrant separate management strategies.

Citation
Somers CM, Graham CF, Martino JA, Frasier TR, Lance SL, Gardiner LE, et al. (2017) Conservation genetics of the eastern yellow-bellied racer (Coluber constrictor flaviventris) and bullsnake (Pituophis catenifer sayi): River valleys are critical features for snakes at northern range limits. PLoS ONE12(11): e0187322. https://doi.org/10.1371/journal.pone.0187322

Saturday, November 4, 2017

The origin of Australian squamates


Eastern Tiger Snake, Notechis scutatus
Deadly snakes are among Australia's most iconic animals. Now a new study led by The Australian National University (ANU) has helped explain how they descended from creatures that have come from Asia over the past 30 million years.

Lead researcher Dr Paul Oliver said about 85 percent of more than 1,000 snake and lizard species in Australia descended from creatures that floated across waters from Asia to Australia.

The research helps explain how Australia has become home to about 11 percent of the world's 6,300 reptile species -- the highest proportion of any country around the world.

"Around 30 million years ago it appears that the world changed, and subsequently there was an influx of lizard and snakes into Australia," said Dr Oliver from the ANU Research School of Biology.

"We think this is linked to how Australia's rapid movement north, by continental movement standards, has changed ocean currents and global climates."

The researchers conducted the study using animal tree-of-life data combined with empirical evidence and simulations.

The origins for reptiles contrast with other famous Australian animal groups including marsupials and birds, which include many more species descended from ancestors that lived on Gondwana, a supercontinent that included Australia, Antarctica, South America, Africa and Madagascar.

Dr Oliver said that the study found that the immigration of reptiles into Australia was clustered in time.

"The influx of lizards and snakes into Australia corresponds with a time when fossil evidence suggests animal and plant communities underwent major changes across the world," he said.

"The movement of Australia may have been a key driver of these global changes."

Oliver PM, Hugall AF. 2017. Phylogenetic evidence for mid-Cenozoic turnover of a diverse continental biota. Nature Ecology & Evolution, 2017; DOI: 10.1038/s41559-017-0355-8

Thursday, November 2, 2017

Marine Snake Diversity in the Straits of Malacca and the South China Sea

Bar graph showing the species composition and relative abundance
 for 852 marine snakes collected as by-catch from otter trawlers 
operating on the  trawling grounds at Sungai Buloh. The snakes 
were collected in 1971 and 1974-75 and represented 10 species 
of true sea snake (Elapidae) and one species of file snake 
(Acrochordidae). The assemblage is strongly dominated by 
Hydrophis curtus (see inset in figure, FMNH 202179) that made 
up 82% of the snake by-catch. The three most common species, 
Hydrophis curtus, Acrochordus granulatus, and Hydrophis 
caerulescensmade up 95% of the sample. 
The following is the abstract from the paper cited below. Prior to World War II, traditional hand-operated fishing methods prevailed throughout Southeast Asia. However, by 1950, mechanized diesel-powered trawlers were being introduced and the modern boom-and bust of fisheries was set into motion. Besides targeted fish, squid, and prawns, otter trawls on the bottom brought up a vast diversity of demersal by-catch including marine snakes. This paper reports on the diversity of the marine snake by-catch obtained from otter trawlers operating at two locations in the Straits of Malacca (Sungai Buloh and Parit Botak) and one location on the eastern coast of the Malay Peninsula (Endau) in the mid-1970s. At Sungai Buloh 11 species of snakes were observed and a single species, Hydrophis curtus, strongly dominated the assemblage, comprising 82% of the by-catch. Eleven species were also observed in the by-catch from Parit Botak but there, three species (Hydrophis fasciatus, H. curtus, and Aipysurus eydouxii) shared dominance with each making up more than 22% of the assemblage. At Endau, 13 species appeared in the by-catch and two species (H. curtus and Hydrophis viperinus) dominated, comprising 33% and 32% of the catch respectively. Besides differences between locations, some small differences in species diversity were detected between collection periods at Sungai Buloh. In addition, a review is undertaken of published trawl surveys of marine snakes in Southeast Asia in the context of the steady depletion of fisheries in the region that took place in the second half of the twentieth century. This review emphasizes that marine snake species diversity needs to be understood on a relatively fine spatial scale and in the context of the health of the fishery as a whole. The entire paper can be found here.

Citation
Voris HK. 2017. Diversity of Marine Snakes on Trawling Grounds in the Straits of Malacca and the South China Sea. Tropical Natural History 17(2):65-87.

Monday, October 30, 2017

The Rediscover of Jackson’s Climbing Salamander (Bolitoglossa jacksoni)

The Search for Lost Species initiative is today celebrating the incredible and unexpected rediscovery of the first of its top 25 “most wanted” lost species, the Jackson’s Climbing Salamander (Bolitoglossa jacksoni), lost to science since its discovery in 1975. The rediscovery comes months before an organized expedition to Guatemala’s Cuchumatanes Mountain range to look for the animal, and was made possible in part because a group of organizations, including Global Wildlife Conservation and Rainforest Trust, established the Finca San Isidro Amphibian Reserve in 2015 to help protect the species’ habitat.
Photo by Carlos Vasquez Almazan

“I love this story because it conveys how protecting habitat gives species a fighting chance to survive on this planet,” said Don Church, president of GWC and Search for Lost Species lead. “This rediscovery can only be a good omen for the future of the Search for Lost Species campaign. It’s a sign that if we get out there and work at it, many of these species can be found and saved.”

A guard at the Finca San Isidro Amphibian Reserve, Ramos León, discovered a juvenile Jackson’s climbing salamander—only the third individual ever seen—on the edge of the reserve while out on patrol this month. He sent a photo to Carlos Vasquez, curator of herpetology at USAC University in Guatemala and coordinator of the amphibian conservation program at local NGO and GWC partner FUNDAECO, who confirmed that the species in the photo was, indeed, the Jackson’s climbing salamander.

Vasquez has been on more than 30 trips to find the species, nicknamed the “golden wonder” for its brilliant yellow hues, since 2005, spending more than 3,000 hours in search of it. Earlier this year he led a workshop for the reserve’s four guards to show them photos of the salamander and to discuss where they may find it—in moss, leaves or bark—while out on patrol in the reserve during the rainy season. His efforts paid off.

“I explained to them how important this species is and I left a poster there so they could see a picture of the Jackson’s climbing salamander every single day,” Vasquez said. “We had started to fear that the species was gone, and now it’s like it has come back from extinction. It’s a beautiful story, and marks a promised future for the conservation of this special region.”

The guard rediscovered the salamander 300 meters higher than where the species was discovered in 1975 by Jeremy Jackson (after whom the salamander is named) and Paul Elias, two American friends who spent time exploring the jungles of Guatemala in the 1970s. On their adventures, they also discovered the Finca Chiblac salamander and the long-limbed salamander. All three species went unseen for more than three decades until Vasquez rediscovered the Finca Chiblac salamander in 2009 and the long-limbed salamander in 2010. The Jackson’s climbing salamander was the last of the missing triad.

In 2015, spurred by the 2014 expedition and the earlier rediscovery of the Finca Chiblac salamander and the long-limbed salamander, a consortium of international groups—GWC, MUSHNAT, FUNDAECO World Land Trust, Rainforest Trust, the International Conservation Fund of Canada and the Amphibian Survival Alliance—established the Finca San Isidro Reserve (also called the Yal Unin Yul Witz Reserve) to protect some of the last remaining habitat for the species.

“When 40 years later [after we discovered the species] as an act of faith, a tract of land next to where we discovered it was protected, we all held our breath hoping that this exceptional phantom would reappear,” said Elias, who today is a partner at a private investment firm in Boston. “The rediscovery of this rarest of the rare shows how important habitat preservation is to the persistence of these special animals in these exceptional places, and for me personally it is a moment of sheer joy.”

Global Wildlife Conservation, FUNDAECO and Rainforest Trust are now joining forces to expand the reserve to protect the Jackson’s climbing salamander and a treasure trove of additional endemic and endangered Guatemalan species threatened by climate change, habitat loss and infectious disease. GWC will be launching a #GivingTuesday fundraising campaign in November to help support the expansion of the reserve.

In the meantime, Vasquez and team are conducting research where the salamander was found to better understand the species’ ecology and will continue to spend time in the field to look for additional individuals to assess the population.

Western Rat Snakes and Resource Selection

 Western Ratsnakes (Pantherophis obsoletus)
Predicting the effects of global climate change on species interactions has remained difficult because regional climate models and the microclimates experienced by organisms are not always in sync. In a new paper George et al. (2017) evaluated resource selection in a predominant ectothermic predator using a modeling approach that permitted them to assess the importance of habitat structure and local real-time air temperatures within the same modeling framework. The authors radio-tracked 53 western ratsnakes (Pantherophis obsoletus) from 2010 to 2013 in central Missouri, USA. The researchers used study sites where this species was previously linked to prey population demographics.  Bayesian discrete choice models within an information theoretic framework were used to evaluate the seasonal effects of fine-scale vegetation structure and thermal conditions on ratsnake resource selection. Ratsnake resource selection was influenced most by canopy cover, canopy cover heterogeneity, understory cover, and air temperature heterogeneity. Ratsnakes preferred habitats with greater canopy heterogeneity early in the active season, and greater temperature heterogeneity later in the season. This seasonal shift potentially reflects differences in resource requirements and thermoregulation behavior. Predicted patterns of space use indicate that ratsnakes preferentially selected open habitats in spring and early summer and forest–field edges throughout the active season. The results show that downscaled temperature models can be used to enhance our understanding of animal resource selection at scales that can be addressed by managers. The authors suggest that conservation of snakes or their prey in a changing climate will require consideration of fine-scale interactions between local air temperatures and habitat structure.

Citation
George AD, Connette GM, Thompson FR, Faaborg J. 2017. Resource selection by an ectothermic predator in a dynamic thermal landscape. Ecology and Evolution. 2017.

Friday, October 27, 2017

A new, hybrid, all female whiptail that is tetraploid


The Desert Grasslands Whiptail, Aspidoscelis inornatus. 
In a new paper, Cole et al. (2017) describe the second known tetraploid amniote that reproduces by parthenogenetic cloning. This all-female species of whiptail lizard originated in the laboratory from hybridization between the  Little Striped Whiptail, Aspidoscelis uniparens (triploid parthenogen) and the Desert Grasslands Whiptail, Aspidoscelis inornatus (diploid bisexual species). Similar clonal lineages of tetraploids arose from at least 44 F1 hybrid females. These were produced by at least 15 Aspidoscelis uniparens that mated with several different males of Aspidoscelis inornatus from both New Mexico and Arizona stock.

Inheritance of alleles at eight microsatellite deoxyribonucleic acid (msDNA) loci in the tetraploid species confirms its parentage, whereas DNA quantification and behavior of chromosomes in meiosis demonstrate that tetraploidy and heterozygosity are maintained generation after generation.

The authors compared univariate and multivariate variation in scalation between the tetraploids, their parental taxa, and four museum specimens from New Mexico that were reported as putative hybrids. Two of the putative hybrids are confirmed as such, but the other two are the Little Striped Whiptail, Aspidoscelis inornatus and the Desert Grasslands Whiptail, Aspidoscelis uniparens. The similarities of Aspidoscelis uniparens and the tetraploids suggest that tetraploid females may exist in old samples misidentified as Aspidoscelis uniparens. Clones of the tetraploid species are so similar to each other in morphology and msDNA that they authors could not distinguish most individuals or separate lineages from the P1 through multiple generations (up to F7) on the basis of the 12 msDNA loci analyzed in this study.

Discussion of the taxonomic aspects of the multiple hybrid origins of similar clones concludes that one specific name should be applied to all of them. For some systematists, depending on the species concept preferred, these lizards represent a complex of multiple cryptic species that cannot be reliably identified or diagnosed (one species for each F1 hybrid female that cloned a lineage). These specimens of known parentage provide valuable insights for the taxonomic treatment of natural parthenogenetic clones. In addition, the authors show that the degree of morphological variation in clonal parthenogens and bisexual Aspidoscelis inornatus can be similar to each other. They provide a new name for this new species, Priscilla’s Whiptail Lizard, Aspidoscelis priscillae.

Citation
Cole CJ, Taylor HL, Neaves WB, Baumann DP, Newton A, Schnittker R, Baumann P. The Second Known Tetraploid Species of Parthenogenetic Tetrapod (Reptilia: Squamata: Teiidae): Description, Reproduction, Comparisons With Ancestral Taxa, And Origins Of Multiple Clones. Bulletin of the Museum of Comparative Zoology. 2017 Oct 17;161(8):285-321.

Thursday, October 26, 2017

The endangered Lanceheads of Martinique


Martinique Lancehead, Bothrops lanceolatus.
Photo credit Nathalie Dewynter
In a new paper, Gros-Désormeaux et al. discuss the impact of humans on the Martinique Lancehead, Bothrops lanceolatus. The lancehead is the only poisonous snake endemic to Martinique, Lesser Antilles arc. Today, this snake is on the verge of extinction. The recorded number of snakes killed yearly between 1970 and 2002 decreased by 97%. Despite the production of an antivenom in 1993, the local authorities set up a financial reward to encourage the eradication of lancehead snakes. Today the local population still perceives the snake as a threat, due to its fatal venom and its fierce behaviour. The case study of the lancehead in Martinique highlights the need to develop integrated strategies to conserve poisonous snakes on densely populated islands. This requires innovative, cross-sectoral strategies that involve decision-makers working along with multi-disciplinary scientists. Approaching the complexity of ecosystems through the socio-ecological prism implies, conversely, linking up the domains of science and technology, life and environmental sciences, and human and social sciences, through interactions based on sharing common assumptions

Citation
Gros-Désormeaux JR, Lagabrielle E, Lesales T, Exilie I, Tupiassu L, Béchacq D. Living with or Eradicating Poisonous Snakes in Densely Populated Caribbean Islands—A Socio-Ecological Challenge for the French West Indies. Open Journal of Animal Sciences. 2017 Sep 4;7(04):405.

Wednesday, October 25, 2017

Fossil snakes from the Bahamas


Nerodia clarki
The late Pleistocene snake fossils from Sawmill Sink (Abaco, The Bahamas) represent five taxa: a blindsnake or threadsnake (Scolecophidia); the Abaco boa (Boidae: Chilabothrus cf. exsul); a rat snake (Colubridae: Pantherophis sp.); a water snake (Natricidae: Nerodia sp.); and the Cuban racer (Dipsadidae: Cubophis cf. vudii). A scolecophidian, lChilabothrus exsul, and Cubophis vudii still exist on Abaco and have been previously recovered in fossil deposits in the West Indies. In contrast, no forms of Pantherophis or Nerodia have been reported as fossils anywhere in the West Indies until now. This is the first evidence of any indigenous species of Pantherophis (living or extinct) in the Caribbean, whereas the only indigenous Nerodia in the West Indies is the extant N. clarkii along the northern coast of Cuba. In being present on Abaco in late Pleistocene but not Holocene contexts, Pantherophis sp. and Nerodia sp. resemble 17 species of birds that apparently did not survive the dramatic changes in climate, habitat, and land area associated with the Pleistocene–Holocene Transition in The Bahamas. It is likely that Pleistocene fossils of both Pantherophis and Nerodia will be found eventually on other Bahamian islands. With the discovery of these two snakes, the vertebrate fauna of Sawmill Sink now stands at 97 species, by far the richest in the West Indies.

Citation
Mead JI, Steadman DW. Late Pleistocene snakes (Squamata: Serpentes) from Abaco, The Bahamas. Geobios. 2017 Oct 10.

A warming climate and viviparous lizards


Phrynocephalus sp.
Climate change is and will continue to have a negatively impacting biodiversity. In a new paper Wang et al. (2017) note that lizards may experience population declines and extinctions on a similar scale to that experienced by amphibians.  Within lizards, viviparous species are hypothesized to be more vulnerable to climate warming, because they have evolved reduced body temperature and heat tolerance, but this idea remains untested. To test this hypothesis, Wang et al. conducted three temperatures (20, 24, and 28 °C) factorial designed experiments on two lizard species Phrynocephalus przewalskii (oviparous) and P. putjatia (viviparous). The experiments simulated warming on oviparous versus viviparous lizards. Their manipulation of ambient temperature affected activity and thermal preference in both species, birth dates in P. putjatia, and egg mass in P. przewalskii. The other examined traits (fecundity, reproductive output, and size, morphology, and sprint speed of offspring) were not affected. Neither lizard species showed different behavioral responses to rising temperatures between the sexes. The viviparous species thermoregulated more actively than did the oviparous species, but the two species did not differ in thermal preference. Warming reduced the activity time allotted for thermoregulation in both species, but the effect was more dramatic in the viviparous species. Their data supports one of the central predictions that lead to the hypothesis that viviparous lizards are more vulnerable to climate warming. Warming constrains activity more dramatically in viviparous species, not because viviparous lizards have evolved reduced body temperature and heat tolerance.

Citation
Wang Z, Ma L, Shao M, Ji X. Are viviparous lizards more vulnerable to climate warming because they have evolved reduced body temperature and heat tolerance?. Oecologia. 2017 Oct 10:1-0.

Monday, September 25, 2017

Caribbean Ameivas moved to the genus Pholidoscelis



The family Teiidae is a New World clade of small to large-sized lizards that tend to be active foragers, diurnal, and omnivorous. Whiptails (genus Aspidocelis)in the USA, Racerunners (genus Cnemidophorus) in the Neotropics, the giant Tegus (Tupinmabis and Salvator) in the Neotropics are a few of the major clades. The Ameiva's are primarily Neotropical but also are well represented in the West Indies. In a new paper Tucker et al. (2017) examine the phylogenetic relationships and biogeographic history of Caribbean island ameivas and place them in the genus Pholidoscelis. The authors use phylogenomic and mitochondrial DNA datasets to reconstruct a well-supported phylogeny and assess historical colonization patterns in the group. They obtained sequence data from 316 nuclear loci and one mitochondrial marker for 16 of the 19 extant species of the Caribbean endemic genus Pholidoscelis. To estimate divergence times, they used fossil teiids to calibrate a timetree which was used to elucidate the historical biogeography of these lizards. All phylogenetic analyses recovered four well-supported species groups (clades) recognized previously and supported novel relationships of those groups, including a (P. auberi + P. lineolatus) clade (western + central Caribbean), and a (P. exsul + P. plei) clade (eastern Caribbean). Divergence between Pholidoscelis and its sister clade was estimated to have occurred ~25 Ma, with subsequent diversification on Caribbean islands occurring over the last 11 Myr. Of the six models compared in the biogeographic analyses, the scenario which considered the distance among islands and allowed dispersal in all directions best fit the data. These reconstructions suggest that the ancestor of this group colonized either Hispaniola or Puerto Rico from Middle America. The authors provide a well-supported phylogeny of Pholidoscelis with novel relationships not reported in previous studies that were based on significantly smaller datasets. They propose that Pholidoscelis colonized the eastern Greater Antilles from Middle America based on our biogeographic analysis, phylogeny, and divergence time estimates. The closing of the Central American Seaway and subsequent formation of the modern Atlantic meridional overturning circulation may have promoted dispersal in this group.

Citation
Tucker DB, Hedges SB, Colli GR, Pyron RA, Sites JW. Genomic timetree and historical biogeography of Caribbean island ameiva lizards (Pholidoscelis: Teiidae). Ecology and Evolution. 2017 Aug.

A frog that cannot hear its own call


Pumpkin toadlets, found in the leaf litter of Brazil's Atlantic forest, are among the smallest frogs in the world.

An international team from Brazil, Denmark, and the United Kingdom, has discovered that two species of these tiny orange frogs cannot hear the sound of their own calls.

This is a unique case in the animal kingdom of a communication signal persisting even after the target audience has lost the ability to detect it.

"We have never seen this before: These frogs make sounds that they cannot hear themselves," says Associate Professor, Jakob Christensen-Dalsgaard, University of Southern Denmark.

He led the laboratory testing of the frogs' hearing abilities at the University of Southern Denmark. The findings have been confirmed by anatomical studies at Cambridge University, UK, showing that the part of the ear responsible for high-frequency hearing is vestigial in these species.

Lead author of the study is Dr. Sandra Goutte, who was postdoc at Universidade Estadual de Campinas, São Paulo, Brazil, when the study was conducted.

Most male frogs call to signal their presence to the opposite sex and find a mate, but this is costly: it could attract predators and parasites, and it uses up energy and time.

"One would think that if a signal is not perceived by its target audience, it would be lost through evolution," says Dr. Sandra Goutte.

Because these tiny frogs are brightly colored, diurnal and known to use visual signals, the researchers hypothesize that visual communication has replaced acoustic communication.

The movement of the throat when males are calling could constitute a visual signal, in which case the call itself would represent a by-product of the true signaling behavior.

Like many brightly-colored tropical frogs, pumpkin toadlets are highly toxic, which may lower the risk of predation when they are calling.

The singular communication system in these pumpkin toadlets is the first example of vestigial sound communication, says Jakob Christensen-Dalsgaard.

Studying the toadlets further will advance our understanding of the mechanisms underlying the evolution of communication systems in animals.

Citation
 Goutte S, Mason MJ, Christensen-Dalsgaard J, Fernando Montealegre-Z F. Chivers BD, Sarria-S FA,  Antoniazzi MM,  Jared C,  Sato LA,  Toledo LF. 2017. Evidence of auditory insensitivity to vocalization frequencies in two frogs. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-12145-5

Sunday, May 28, 2017

A new, morphologically cryptic, leaf-nesting frog of the genus Phyllomedusa


Male holotype of Phyllomedusa chaparroi sp. nov. (MUBI 13986) 
Casttoviejo-Fischer and colleagues describe and name the new leaf-nesting frog, Phyllomedusa chaparroi, a medium-sized species (67.9–77.5 mm) from the Amazonian rainforests of northern Peru. Morphologically the new species is most similar to P. boliviana and P. camba, it is indistinguishable from the latter in external qualitative and quantitative traits). However, phylogenetic analysis of combined mitochondrial and nuclear markers place the new species sister to a clade containing P. neildi, P. tarsius, and P. trinitatis. Phyllomedusa chaparroi can be readily differentiated from these species by having a dark reddish-brown iris with indistinct tiny orange spots versus an orange iris with marked dark reticulation found in P. neildi, P. tarsius, and P. trinitatis. Furthermore, the genetic distances for a 532 bp sequence of the 16S gene between the new species and its sister species are 2.8–4.1%, whereas distances are 4.5–5.5% to the morphologically cryptic P. camba. The type series of Phyllomedusa chaparroi includes specimens from two sites, this species seems to occur at various localities in the area of Tarapoto in the Peruvian Amazon. Nonetheless, it seems that this species has been confused with Phyllomedusa camba and the distributional range of both species needs to be thoroughly evaluated, especially at the northern western limits of the known distribution of P. camba.

Citation
Castroviejo-Fisher SA, Köhler J, De La Riva IG, Padial JM.. A new morphologically cryptic species of Phyllomedusa (Anura: Phyllomedusidae) from Amazonian forests of northern Peru revealed by DNA sequences. Zootaxa. 2017 May 22;4269(2):245-64.


Saturday, May 27, 2017

Brazilian microteiids - and the increase of Brazilian lizard species since 1995

Gymnophthalmus underwoodi, a widespread all-female species.
In a new paper, Ribeiro-Junior and Amaral present distribution data of all Alopoglossidae and Gymnophthalmidae lizards known from the Brazilian Amazonia. The paper presents a total of 54 species-level taxa, belonging to 17 genera and two families. This represents 22 more species-level taxa than previously reported. The results  were based on the examination of 17,431 specimens deposited in three North American and eight Brazilian museums, including the main collections harboring Amazonian material. Most species (~80%) are endemic to Amazonia; non-endemic species are mainly associated with open vegetation (savanna) enclaves or open dry (semi-deciduous) forest in Amazonia, with a few exceptions. As a whole, seven taxa (including one species complex) are widespread in Amazonia, six are restricted to eastern Amazonia, seven to western Amazonia, two to southwestern Amazonia, 11 to southern Amazonia, 11 to northern Amazonia (either in part of it or widespread in the Guiana region), and six to the southern peripheral portion of Amazonia. Besides, four species present unique distributions. Considering this study and the other three catalogues of distribution of lizards already published, the total number of lizard species from Brazilian Amazonia increased from 97 to 142 species-level taxa. This represents an increase of 45 species from the region since the last revision in 1995.

Citation
Ribeiro-Junior MA, Amaral S. 2017. Catalogue of distribution of lizards (Reptilia: Squamata) from the Brazilian Amazonia. III. Anguidae, Scincidae, Teiidae. Zootaxa. 2016 Dec 9;4205(5):401-30.

Do not publish


David Lindenmayer, Ben Scheele
Science  26 May 2017:Vol. 356, Issue 6340, pp. 800-801DOI: 10.1126/science.aan1362

Biologists have long valued publishing detailed information on rare and endangered species. Until relatively recently, much of this information was accessible only through accessing specialized scientific journals in university libraries. However, much of these data have been transferred online with the advent of digital platforms and a rapid push to open-access publication. Information is increasingly also available online in public reports and wildlife atlases, and research published behind paywalls can often be found in the public domain. Increased data and information accessibility has many benefits, such as helping to improve repeatability in scientific studies and enhancing collaboration (1, 2). However, such readily accessible information also creates major problems in the context of conserving endangered species.

Increasingly, the dual-use research dilemma (3), in which research can have both substantial positive but also negative impacts, is pervading research on rare and endangered species, with information intended to aid conservation fueling illegal actions that harm biodiversity. Biologists must urgently unlearn parts of their centuries-old publishing culture and rethink the benefits of publishing location data and habitat descriptions for rare and endangered species to avoid unwittingly contributing to further species declines. Restricting information entails some costs, but these must be weighed against the increasing harm of unrestricted information accessibility.

At least three key issues associated with unrestricted access to information on rare and endangered species warrant careful attention. These risks are not new but are greatly exacerbated in an era of digital proliferation and open access. First, unrestricted access to species location information is facilitating a surge in wildlife poaching (4, 5), with many species at risk (6). Poaching has been documented in species within months of their taxonomic description in journals (4). For example, more than 20 newly described reptile species have been targeted in this way, potentially leading to extinction in the wild. Indeed, when the names of some of these species—such as the Chinese cave gecko, Goniurosaurus luii (see the photo)—are typed into a search engine, the text autopopulates to suggest a search to purchase these animals.

Second, unrestricted access to location data and habitat descriptions can disrupt the often delicate relationships between scientists and landowners. We have personal experience of this. Our research in Australia on restoring farmland biodiversity requires repeated access to farms and depends on high levels of trust among landholders. We have detected populations of endangered species such as the pink-tailed worm-lizard (Aprasia parapulchella). Our research permits demand that location records be uploaded to open-access government wildlife atlases. Soon after uploading records, people seeking the rare worm-lizard were caught trespassing, upsetting farmers, damaging important rocky outcrop habitats, and jeopardizing scientist-farmer relationships that have taken years to establish.

Third, unrestricted access to species information has the potential to accelerate habitat destruction and create other negative disturbances. The digital age has brought a desire among many nature enthusiasts to observe, photograph, and sometimes remove animals and plants (7). Animal behavior and habitats are often heavily disturbed in the process (8).

Decisions to publish sensitive information on endangered and newly described rare species must be based around a careful assessment of whether its publication will benefit or harm the target species (see the figure). Key trade-offs must be weighed. For example, easily accessible data can help amass the evidence to challenge development proposals that may affect endangered species. Increased data accessibility can also foster improved scientific repeatability and greater collaboration. Although withholding information may have some negative consequences, this action is increasingly needed (9), given that calls for better regulation and law enforcement to protect atrisk species have met limited success (4, 5).

Where species have high economic value (such as in the case of the Chinese cave gecko), withholding information may be the only option. Relevant government or regulatory agencies should be notified of scientific discoveries, and pathways for access from legitimate persons remain open. In moderate risk situations, spatial data might be buffered and only very broad location data provided. Where there is low risk of perverse outcomes, unrestricted publication of habitat descriptions and location information remains appropriate (see the figure).

Much information on endangered and newly described species can still be published without location data being provided and without undermining the integrity or repeatability of the scientific work [akin to the notion that the rediscovery of Lazarus species can be validated without the collection of voucher specimens (10)]. As such, negative trade-offs arising from the dual-use research dilemma are not as pronounced as in other fields. For example, restrictions on publishing methodological advances in the study of pathogen virulence can inhibit scientific research that can have considerable human health benefits but is sometimes deemed necessary because of the potential for this information to facilitate perverse outcomes (such as bioterrorism) (11, 12).

Endangered or newly discovered species can be at risk from poachers if their location data is published. This scheme helps to assess whether publication should be restricted in particular cases.

Some fields such as paleontology and archaeology have long maintained restrictions on the publication of site locations and promoted government policies and regulations to limit collection and trade in fossils, artefacts, and culturally sensitive and/or scientifically important material (13). Organizations such as the U.S. Forest Service do not disclose geospatial data in order to protect research sites (14). Other solutions include modification of research permits so that endangered species locations are not automatically uploaded into wildlife databases and masking such records on private land, as presently occurs in some states in the United States. Some of these approaches are already in place in conservation; for example, the open-access journal PLOS ONE has data exemptions for endangered species. However, current policies are specific to individual journals, data repositories, or organizations and lack consistent enforcement. A major benefit to the author-led self-censorship that we advocate is that restrictions of the dissemination of sensitive information can be implemented widely and immediately.

There are signs that this problem is beginning to be addressed. Journals such as Zootaxa that carry taxonomic descriptions of new species now publish new descriptions without location information (15). More researchers, journal editors, and data custodians need to follow their lead. Otherwise, the potential benefits of open-access scientific information and data for biodiversity conservation will be outweighed by the perverse effects of exposing wild populations to substantial added conservation threats. Although much information on endangered and rare species is already available online, it remains crucial to change our actions now to avoid unwittingly contributing to further species declines.

Call to keep secrets on rare species draws reluctant support

By Warren Cornwall

The extent to which rare animal poachers piggyback on scientific research became clear to Mark Auliya soon after he published a 2012 paper announcing the discovery of the Borneo earless monitor lizard (Lanthanotus borneensis) in a new part of the southeast Asian island.

The conservation biologist at the Helmholtz Centre for Environmental Research in Leipzig, Germany, had left the lizards’ location vague, in an attempt to shield the animal from collectors and their suppliers. Nevertheless, within a year, the lizard was turning up outside Borneo.
After scientists published a paper documenting a new 
population of earless monitor lizards in Borneo, poachers
 moved in.

So Auliya embraces a new call, published today in Science, for scientists to keep mum about details that could turn rare and sought-after species into the next easy target for the global wild animal trade. “It’s terrible,” he says. “If you describe a new species in the Democratic Republic of Congo, you should probably only list the country.” In today’s Perspective, two Australian conservation biologists urge scientists to adopt a policy of strategic “self-censorship” to shield the animals and plants they study. For species that are likely targets for collectors, they urge scientists to share detailed information about where the species is found only with government agencies, while hiding it from the public.

Such secrecy runs counter to the imperative to share research with the scientific world, and the push to make it quickly and widely available. But that openness is taking a devastating toll, says David Lindenmayer, the article’s lead author and a conservation biologist at The Australian National University in Canberra.  “For some of the really important species, if we don’t do something they’re going to get wiped off the map.”

He was alerted to the intensity of the problem in 2016, when he got a call from a landowner about people tearing apart rocky outcrops with crowbars. Lindenmayer figured out that the interlopers were on the hunt for the rare pink-tailed worm-lizard (Aprasia parapulchella), a bizarre legless gecko that grows to 15 centimeters, spends its life in rocky fissures in Australia, feeds on ants, and squeaks when picked up. The animal’s location at the farm was first reported just weeks earlier, from information the government requires Lindenmayer to provide in an open-access online database.

Since then, he has gathered accounts from fellow scientists about a host of species targeted for poaching shortly after their discovery was published. He fears that this pressure has only increased as new scientific research becomes available to the world with the click of a mouse. “The era of online data, of open-access data, data in real time, all those kinds of things, opens up a whole new set of opportunities for people who want to poach animals,” he says.

This entanglement of science and poaching isn’t new, says Mark Burgman, a conservation biologist at Imperial College London, and editor-in-chief of the journal Conservation Biology. Neither is the use of scientific subterfuge to foil thieves. The pressure is acute for rare or unusual species sought by collectors: amphibians, orchids, birds, and reptiles—particularly venomous snakes. One paper he published about the discovery of a plant included a map that had been manipulated to make the location indiscernible. He worked with the journal to create the altered map. In Australia in the 1980s, he managed a database for state government that listed the locations of certain species only down to within roughly a hundred kilometers, to make them harder to find.

Burgman says secrecy should be handled on a case-by-case basis between scientists and sources of scientific information, such as journals. Any secret information can be revealed to other scientists or government officials on a need-to-know basis.

But there are drawbacks to shielding new data, says Bryan Stuart, a herpetologist at the North Carolina Museum of Natural Sciences in Raleigh. Information about a species’ location can be crucial to guiding conservation efforts. And such information can still leak out through avenues such as museum collections, he says. “I believe that withholding locality data is only a temporary measure,” he wrote in an email.

Stuart co-wrote a 2006 letter in Science urging scientists to try to address the poaching problem by working closely with conservation managers to have protections for the species in place when the research is published. He acknowledges, however, that this approach won’t always succeed.

Auliya, meanwhile, hopes the new attention might revive his attempt to host a workshop where scientists can hash out guidelines for how to publish their findings without imperiling the very species they are studying. In 2012 he tried to arrange such a gathering, but couldn’t get it funded. 

Thursday, May 25, 2017

Cuban boas coordinate their hunting behavior

Snakes have long been thought to be solitary hunters. A new study from the University of Tennessee, Knoxville, shows that the Cuban boa (Chilabothrus angulifer) coordinate their hunts to increase their chances of success. Vladimir Dinets, a research assistant professor of psychology at the University of Tennessee, observed Cuban Boa's hunting behavior in bat caves. Many Cuban caves shelter large bat colonies, and in some of them small populations of boas regularly hunt bats as they fly out at dusk and return at dawn. Dinets noticed that the boas hung down from the ceiling of the cave entrance and grabbed passing bats in midair. He found that if more than one boa was present, the snakes coordinated their positions in such a way that they formed a wall across the entrance. This made it difficult or impossible for the bats to pass without getting within striking distance of at least one boa. Such group hunts were always successful, and the more snakes present the less time it took each to capture a bat. But if there was only one boa, it sometimes failed to secure a meal. These findings were recently published open-access in the journal Animal Behavior and Cognition. To date, only a handful of snakes have been observed hunting in groups, and coordination among them -- or among any other group-hunting reptiles -- has never been proven, Dinets said. Only a few of the world's 3,650 snake species have ever been observed hunting in the wild, so very little is known about snakes' diverse hunting tactics. "It is possible that coordinated hunting is not uncommon among snakes, but it will take a lot of very patient field research to find out," Dinets said. He added that observing the Cuban boa, although an amazing spectacle, is becoming increasingly difficult since only the most remote caves still have boas. The boas are being hunted for food and possibly pet trade. "I suspect that if their numbers in a cave fall, they can't hunt in groups anymore and might die out even if some of them don't get caught by hunters," Dinets said. "A few of these caves are in national parks, but there's a lot of poaching everywhere."




Citation

 Dinets V. 2017. Coordinated hunting by Cuban boas. Animal Behavior and Cognition, May 2017 DOI: 10.12966/abc.02.02.2017

Coral snake mimic loses pattern in absences of coral snake model

Tobago's Erythrolamprus ocellatus above. Trinidad's coral snake 
mimic E.  
aesculapii below.
Losses of adaptations in response to changed selective pressures are evolutionarily important phenomena but relatively few empirical examples have been investigated in detail. To help fill this gap, Hodson and Lehtinen took advantage of a natural experiment in which coral snake mimics occur on two nearby tropical islands, one that has coral snake models (Trinidad) and one that lacks them (Tobago).

The Tobago snake's pattern represents a loss of an adaptation in response to changed selective pressures. Relatively few empirical examples of adaptation loss have been investigated in detail. Hodson and Lehtinen took advantage of a natural experiment in which coral snake mimics occur on two nearby tropical islands, one that has coral snake models (Trinidad) and one that lacks them (Tobago). On Tobago, an endemic coral snake mimic (Erythrolamprus ocellatus) exists but has a relatively poor resemblance to coral snakes. Quantitative image analysis of museum specimens confirmed that E. ocellatus is a poor mimic of coral snakes.

To address questions related to the functional importance of this phenotype, the authors conducted a field experiment on both islands with snake replicas made of clay. These results clearly indicated a strong inter-island difference in predator attack rates where snake replicas that resembled coral snakes received protection in Trinidad but not in Tobago. Color patterns from museum specimens confirmed that E. ocellatus is indeed a poor mimic of coral snakes in many respects, especially in regards to the relative proportions of colors and the lack of discrete band. This implies that the classic coral snake mimicry adaptation has been degraded in this species. Field experiment revealed that E. ocellatus replicas were not protected from predator attacks on Tobago (where no coral snakes occur) compared to controls. However, on Trinidad (where coral snakes do occur) we found the expected lower attack rate on coral snake and mimic replicas compared to controls. Thus, E. ocellatus does not just look like a poor mimic to human eyes, its predators show no evidence of avoiding it.

Further, a molecular phylogenetic analysis of the ancestry of E. ocellatus revealed that this poor coral snake mimic is deeply nested in a clade of good coral snake mimics. Therefore the lack of coral snakes on Tobago altered the selective environment such that the coral snake mimicry adaptation was no longer advantageous. The failure to maintain this ancestral feature in allopatry provides a compelling example of how losses of complex adaptations can occur.

Citation
Hodson EE, Lehtinen RM. 2017. Diverse Evidence for the Decline of an Adaptation in a Coral Snake Mimic. Evolutionary Biology. 2017:1-0.

Monday, May 22, 2017

The last European varanid

The Desert Monitor, Varanus griseus is the extant species
with the closest distribution to Europe today
In a recent paper, Georgalis et al. (2017) report the remains of a varanid lizard from the middle Pleistocene of the Tourkobounia 5 locality near Athens, Greece. The new fossil material comprises cranial elements only (one maxilla, one dentary, and one tooth) and is attributed to the monitor lizard genus Varanus, the genus to which all European Neogene varanid remains have been assigned. Previously, the most recent undisputed varanid from Europe had been recovered from upper Pliocene sediments. The new Greek fossils, therefore, constitute the most recent records of monitor lizards from the continent. Despite being incomplete, this new material enhances our understanding of the cranial anatomy of the last European monitor lizards and is clearly not referable to any of the extant species such as Varanus griseus or Varanus niloticus - the only species that could be taken into consideration on a present-day geographic basis. However, these fossils could represent a survivor of the monitor lizards of Asian origin that inhabited Europe during the Neogene. Varanids first appear in the European fossil record during the Eocene. They are entirely absent from the European Oligocene faunas but appear again in the fossil record after the early Miocene. It is possible the European Paleogene varanids were victims of the Grande Coupure. The Grande Coupure refers to a break or change in faunal continuity about 33.5 MYA and marks the the end of the Eocene assemblages of mammals, with the arrival of Asian species in Europe. The authors note that on the basis of the available data this cannot be demonstrated with certainty. All of the Neogene European varanids appear to be members of Varanus, and they seem to have dispersed into Europe in the early Miocene. In fact, the earliest evidence of the genus on the European continent is recorded in the early Miocene of Spain. Whether these early Miocene immigrants originated directly from Africa or have Asian affinities cannot be demonstrated with certainty. The occurrence of Varanus-like forms in the late Eocene and early Oligocene of Egypt favors an African origin, but the Asian record is too weak to offer any insights. The fact that the maxilla from Tourkobounia 5 does not show any relationship with extant African taxa (V. albigularis, V. exanthematicus, V. griseus, V. niloticus, V. ornatus) suggests Asian affinities, as already reported for the extinct Varanus amnhophilis from the late Miocene of Samos. Whatever their exact origin, monitor lizards rapidly achieved a wide distribution throughout Europe during the Miocene. Fossils attributed to this genus have been described from localities in Austria, Germany, Greece, Hungary, Italy, Moldova, Portugal, Romania, Spain, and the Ukraine.

Citation

Georgalis, G. L., A. Villa, and M. Delfino. 2017. The last European varanid: demise and extinction of monitor lizards (Squamata, Varanidae) from Europe. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1301946.

Sunday, May 21, 2017

Some monitor lizards have not recovered from the introduction of the cane toad

Varanus panoptes Image credit: Greg Hume

The impact of invasive species is often underestimated by many. However, invasives can trigger trophic cascades in animal communities but published cases documenting the results of removing top predators are extremely rare. An exception is the invasive cane toad (Rhinella marina) in Australia, which has caused severe population declines in monitor lizards, triggering trophic cascades that facilitated dramatic and sometimes unexpected increases in several prey of the predators, including smaller lizards, snakes, turtles, crocodiles, and birds. Persistence of isolated populations of predators with a decades-long co-existence with toads suggests the possibility of recovery, but alternative explanations are possible. In a new paper, Doody et al. (2017)  note that confirming predator recovery requires longer-term study of populations with both baseline and immediate post-invasion densities. The authors had previously quantified the short-term impacts of the invasive cane toads over seven years at two sites in tropical Australia. In the new paper, they test the hypothesis that predators have begun to recover by repeating the study 12 years after the initial toad invasion. The three predatory lizards (Varanus panoptes, V. mertensi, V. mitchelli) that experienced 71-97% declines in the short-term study showed no sign of recovery, and indeed a worse fate. Two of the three species  (Varanus panoptes and V. mitchelli) were no longer detectable in 630 km of river surveys, suggesting local extirpation. Two mesopredators that had increased markedly in the short-term due to the above predator losses showed diverse responses in the medium-term; a small lizard species increased by about 500%, while populations of a snake species showed little change. Their results indicate a system still in ecological turmoil, having not yet reached a ‘new equilibrium’ more than a decade after the initial invasion; predator losses due to this toxic invasive species, and thus downstream effects, were not transient. Given that cane toads have proven too prolific to eradicate or control, we suggest that recovery of impacted predators must occur unassisted by evolutionary means: dispersal into extinction sites from surviving populations with alleles for toxin resistance or toad avoidance. Evolution and subsequent dispersal may be the only solution for a number of species or communities affected by invasive species for which control is either prohibitively expensive, or not possible.

Citation
Doody JS, Rhind D, Green B, Castellano C, McHenry C, Clulow S. 2017. Chronic effects of an invasive species on an animal community. Ecology. 2017 May 6.



Norisophis begaa, a new basal snake from the early Cretaceous

Image credits: Tyler Keillor (sculpture) and Ximena Erickson
(original photography); modified by Bonnie Miljour. 
Klein et al. (2017) note that fossil snakes are well represented in the Upper Cretaceous of northern Africa (99.7 to 94.3 MYA), with material known from Morocco, Sudan, Egypt, Libya, Algeria, and Niger. The Moroccan Kem Kem beds have yielded a particularly diverse snake assemblage, with members of the families Simoliophiidae, Madtsoiidae, ?Nigerophiidae and several unnamed taxa co-occurring. These fossils are important for our understanding of the early evolutionary history of snakes, and may shed light on the ecology and initial diversification of basal snakes. Klien and colleagues (2017) describe a new taxon, Norisophis begaa, from the Kem Kem beds of Begaa, at  at Aferdou N'Chaft, in southeast Morocco. Although known only from vertebrae, the unique appearance of the fossils adds to our knowledge regarding the early history the snake fauna of the northern Africa's Late Cretaceous. The vertebrae are characterised by a marked interzygapophyseal constriction, parazygantral foramina, an incipient prezygapophyseal process, and an anterio-posteriorly short centrum. Several characteristics shared with Najash, Seismophis, Madtsoiidae, and Coniophis suggest that Norisophis is a stem ophidian. N. begaa further increases the diversity and disparity of snakes within the Kem Kem beds, supporting the hypothesis that Africa was a mid-Cretaceous hotspot for snake diversity.

Citation
Klein CG, Longrich NR, Ibrahim N, Zouhri S, Martill DM. 2017. A new basal snake from the mid-Cretaceous of Morocco. Cretaceous Research. 2017 Apr 30;72:134-41.

The rediscover of some Brazilian anoles and their biogeographic significance

Brazil's Atlantic Forest has montane ranges with an exceptionally high diversity of endemic amphibians and reptiles. Connections between this area and other areas of South America have been proposed as reason. In a new paper Ivan Prates and colleagues report the the rediscovery of Anolis nasofrontalis and Anolis pseudotigrinus, two mainland species from the Brazilian Atlantic Forest that were not reported for more than 40 years.

Coloration in life of Anolis nasofrontalis (A, B) and A. pseudotigrinus (C, D). In A, inset shows the black 
throat lining of A. nasofrontalis. Photographed specimens are females. Ivan Prates

By combine new genetic data with published sequences of species in the Dactyloa clade of Anolis they were able to investigate the phylogenetic relationships of A. nasofrontalis and A. pseudotigrinus, as well as estimate divergence times from their closest relatives.  The phylogenetic analysis recovered six main clades within Dactyloa, five of which were previously referred to as species series (aequatorialis, heterodermus, latifrons, punctatus, roquet). A sixth clade clustered A. nasofrontalis and A. pseudotigrinus with A. dissimilis from western Amazonia, A. calimae from the Andes, A. neblininus from the Guiana Shield, and two undescribed Andean taxa. This allowed them to  define a sixth species series within Dactyloa: the neblininus series. Close phylogenetic relationships between highly disjunct, narrowly-distributed anoles suggest that patches of suitable habitat connected the southern Atlantic Forest to western South America during the Miocene, in agreement with the age of former connections between the central Andes and the Brazilian Shield as a result of Andean orogeny. The data also support the view of recurrent evolution (or loss) of a twig anole-like phenotype in mainland anoles association with montane regions.

The neblininus series is composed of narrowly-distributed species that occur in mid-elevation sites, or adjacent habitats in the case of A. dissimilis, separated by large geographic distances. This pattern suggests a complex biogeographic history involving former patches of suitable habitat between regions, followed by habitat retraction and extinction in the intervening areas. In the case of A. nasofrontalis and A. pseudotigrinus, for instance, past forest corridors may explain a close relationship with the western Amazonian A. dissimilis. Atlantic and Amazonian rainforests are presently separated by open savannas and shrublands, yet geochemical records suggest that former pulses of increased precipitation and wet forest expansion have favored intermittent connections between them. These connections may have also been favored by major landscape shifts as a result of Andean orogeny, such as the establishment of the Chapare buttress, a land bridge that connected the central Andes to the western edge of the Brazilian Shield during the Miocene.

During morphological examinations of A. nasofrontalis and A. pseudotigrinus, it became apparent that these two species are not very different from Caribbean twig anoles, with whom they share short limbs and cryptic coloration. These features are also present in other, distantly-related mainland anoles, such as A. euskalerriari, A. orcesi, A. proboscis, and A. tigrinus. Phylogenetic relationships support that a twig anole-like phenotype was acquired (or lost) independently within Dactyloa, perhaps as a result of adaptive convergence. Alternatively, this pattern may reflect the conservation of an ancestral phenotype. In the former case, an apparent association with South American mountains is intriguing.

Unfortunately, natural history data from A. nasofrontalis and A. pseudotigrinus are lacking. It is currently unclear whether they  exhibit the typical ecological and behavioral traits that characterize the Caribbean twig anole ecomorph, such as active foraging, slow movements, infrequent running or jumping, and preference for narrow perching surfaces.

Citations

Prates I, Melo-Sampaio PR, de Oliveira Drummond L, Teixeira M, Rodrigues MT, Carnaval AC. 2017. Biogeographic links between southern Atlantic Forest and western South America: rediscovery, re-description, and phylogenetic relationships of two rare montane anole lizards from Brazil. Molecular Phylogenetics and Evolution. 2017 May 11.

Prates, I. 2017. Legendary Brazilian Anoles Rediscovered. http://www.anoleannals.org/2017/05/14/legendary-brazilian-anoles-rediscovered/


Friday, May 19, 2017

First warm blooded vertebrate, Ophiacodon?

Ophiacodon mirus. Image Credit ru.wikapedia

People who like watching lizards often get the best opportunity to do so in the morning, as they can usually be found sunbathing at this time of day. This is because they rely on an external energy supply to reach their operating temperature. However, mice and other mammals make themselves nice and cozy in a different way: they burn calories and can even keep themselves warm during a bitterly cold winter's night.

Mammals are thus referred to as warm-blooded. Until now, it was thought that the "body heater" was invented in four-legged land animals around 270 million years ago. "However, our results indicate that warm-bloodedness could have been created 20 to 30 million years earlier," explains Prof. Martin Sander from the Steinmann Institute for Geology, Mineralogy and Paleontology at the University of Bonn.

For long-extinct animals, it is naturally not possible to simply determine body temperature using a thermometer. However, warm-bloodedness leaves behind tell-tale signs in fossils. It not only means that the animal is not reliant on the ambient temperature, but also enables faster growth. "And this is shown in the structure of the bones," explains Sander.

Bones are composites of protein fibers, collagen, and a biomaterial, hydroxyapatite. The more orderly the arrangement of the collagen fibers, the more stable the bone, but the more slowly it normally grows as well. The bones of mammals thus have a special structure. This allows them to grow quickly and yet remain stable. "We call this bone form fibrolamellar," says the paleontologist.

Together with his PhD student Christen D. Shelton (now at the University of Cape Town), the scientist looked at humerus bones and femurs from a long-extinct land animal: the mammal predecessor Ophiacodon. This lived 300 million years ago. "Even in Ophiacodon, the bones grew as fibrolamellar bones," says Sander to summarize the analysis results. "This indicates that the animal could already have been warm-blooded."

Ophiacodon was up to two meters long, but otherwise resembled today's lizards -- and not without good reason: mammals and reptiles are related; they thus share a predecessor. In the family tree, Ophiacodon is very close to the place where these two branches separate.

However, lizards, turtles and other reptiles living today are cold-blooded. Until now, it has been assumed that this was the original form of the metabolism -- i.e. that the shared ancestor of both animal groups was cold-blooded. Warm-bloodedness would thus be a further development, which arose over the course of mammalian evolution.

However, Ophiacodon appears a very short time after the division between mammals and reptiles. "This raises the question of whether its warm-bloodedness was actually a completely new development or whether even the very first land animals before the separation of both branches were warm-blooded," says Sander. That is just speculation. However, if this theory is correct, we would have to drastically correct our image: the first reptiles would then also have been warm-blooded -- and would have only discarded this type of metabolism later.



Citation
Shelton CD, Sander PM. 2017. Long bone histology of Ophiacodon reveals the geologically earliest occurrence of fibrolamellar bone in the mammalian stem lineage. Comptes Rendus Palevol, 2017; DOI: 10.1016/j.crpv.2017.02.00

Tuesday, April 11, 2017

Crack pots, insanity, and some really sick human beings

Snakes provide a variety of ecosystem services, not the least of which is rodent control. This is a free service provide by nature. However, like much of what is free, Republicans insist on privatizing it so somebody can make a profit.

Arizona HB2022 failed on a tie vote yesterday (April 10, 2017). The bill, if passed, would have allowed citizens to shoot "snake shot" within city limits in the State of Arizona. The Arizona Daily Star today (April 11) attributes the failure of the bill to a letter from Mike Cardwell an employee of the San Bernadino County Sherrif's office (California) and a herpetologist. Kudo's to Mike for sending the letter. The Cardwell letter included the following "The bottom line when it comes to destroying small animals like rattlesnakes is that that gun fire presents a much greater danger to by-standers than the snake itself."

Where is the Hantavirus when you need?  Oh, the snakes are controlling the rodents that carry it! The New Mexico Department of Health announced April 7th that a 54-year-old man from San Juan County has died of Hantavirus Pulmonary Syndrome (HPS). This is the second case of HPS confirmed in New Mexico this year. Snakes control rodents that carry this virus and reduce the probability that it will be transmitted to humans.

Just so you understand where this kind of proposed legislation comes from - here is the argument for the law, made by Chris Eger, at Guns.com. The comments that accompany this post are eye-opening.

A House measure advancing through committee would allow the use of specialty ammo inside Arizona cities for snakes and rats but is drawing fire from animal rights groups.
The bill, proposed earlier this month in the state House, has been winding its way through hearings and has gotten an initial nod from lawmakers, though its sponsor cautions it is not an animal regulation proposal.
“It’s a firearms bill,” said Rep. Jay Lawrence, R-Scottsdale. “It’s not a bill that deals with harming snakes or rats or any other vermin, it merely is a firearms bill.”
Lawrence’s measure, HB 2022, would amend state law to allow the use of rat or snake shot to control pests. The cartridges, instead of using a solid bullet, utilize a plastic cap or shell that holds a quantity of small diameter shot. The bill’s language only allows for .22 caliber shot rounds with pellets 1.3mm or less in diameter.
Currently, only the use of blanks is allowed within city limits to control pests.
Not all are impressed by the bill, especially reptile advocates who point out there are at least four species of endangered snakes at large in Arizona.
Russ Johnson of the Phoenix Herpetological Society told local media the proposal is fraught with pitfalls.
“Do we really want people shooting guns in the city limits next to houses?” said Johnson. “You’re talking about shooting rats. So you’re shooting on your rooftop, so you got bird shot spraying everywhere. OK, if you’re shooting a snake, you’re pointing down. You’re gonna get a ricochet even though it’s pellet.”
HB 2022 has passed both the JPS and Rules committees.
Filed Under: Ammunition, Politics & 2nd Amendment


Monday, April 10, 2017

Logging & Leatherbacks


Leatherback turtle hatchlings. Photo Credit: Juan Patiño
 Debris from logging in tropical forests is threatening the survival of hatchling leatherback turtles and the success of mothers at one of the world's most important nesting sites in Colombia.

New research by the University of Exeter and the Doñana Biological Station in Seville, Spain, has found that debris on beaches caused by logging activity is impacting both young turtles and their mothers during the key periods of their life cycles.

Leatherbacks are at particular risk of being caught up in fishing nets and longlines as bycatch, because they are migratory, travelling long distances worldwide.

Many breeding sites are already under pressure from tourism.

But now, research published in the journal Marine Ecology Progress Series has revealed that the logging is an additional, previously underestimated threat.

To nest and breed successfully, females must be able to cross the sandy beaches to dig their nest to successfully incubate their eggs.

In turn, hatchlings must be able to cross the sand unaccompanied to reach the water.

Researchers found that the beach debris hindered this movement.The team monitored 216 turtles, comparing their activity in areas with high amounts of debris to low amounts, in a globally significant nesting site in Colombia.
 
They also manipulated the amount of debris to see how it changed behavior.

They found that females which nested in areas with higher amounts of debris were spent more time building their nest and tended to do so closer to the shoreline.

This meant they were more vulnerable to flooding, which puts their eggs at risk.

Some females were even wounded in the process.

The debris also meant it took longer for hatchlings to reach the sea, increasing their chance of being eaten by predators and meaning they had to expend more energy, making them more vulnerable.

Professor Brendan Godley, director of the Centre for Ecology and Conservation at the University of Exeter's Penryn Campus in Cornwall, is a co-author on the research.

He said: "Leatherback turtles are already under immense pressure, from fisheries bycatch and are also one of the species prone to ingesting marine plastic litter.

"Our research clearly indicates that logging presents another threat.

"It is now paramount that beach clean-up operations are built into logging activities to prevent further damage to this species."

Dr Adolfo Marco Llorente, of the Doñana Biological Station, said: "Although logging debris does not affect rates of nesting, it has a significant impact on where and how nests are built, which negatively affects both mothers and hatchlings.

"This is on a scale that could lead over time to reduction of the overall population.

"Simple measures could make a real difference, such as repositioning organic waste areas, or salvaging the wood debris as an energy source.

"It's also essential that logging practices that reduce the impact on the marine environment are implemented."



 Patino-Martinez J, Godley BJ,  Quiñones L,  Marco A. 2017.  Impact of tropical forest logging on the reproductive success of leatherback turtles. Marine Ecology Progress Series, 569: 205 DOI: 10.3354/meps12064

Friday, April 7, 2017

Lowland amphibians are at higher risk from future climate warming.


A new study of Peruvian frogs living at a wide variety of elevations -- from the Amazon floodplain to high Andes peaks -- lends support to the idea that lowland amphibians are at higher risk from future climate warming.

That's because the lowland creatures already live near the maximum temperatures they can tolerate, while high-elevation amphibians might be more buffered from increased temperatures, according to a study by University of Michigan ecologist Rudolf von May and his colleagues published online April 6 in the journal Ecology and Evolution.

Previous studies have suggested that lowland reptiles and amphibians are especially vulnerable to climate warming. But in most cases, those conclusions were based on computer modeling work that incorporated a limited amount of field data.

"Understanding how species respond to climatic variation is critical for conserving species in future climatic conditions. Yet for most groups of organisms distributed in tropical areas, data about species' critical thermal limits are limited," said von May, a postdoctoral researcher in the U-M Department of Ecology and Evolutionary Biology.

"I think the contribution of our study is that it focuses on a group of closely related frog species distributed along a single montane gradient and that it includes empirical data on species' tolerance to heat and cold, as well as air temperatures measured along the same gradient."

In the process of conducting the study, which involved more than two years of fieldwork, von May and his colleagues identified three previously unknown frog species. Those newly discovered species will be described separately in a series of journal articles.

The elevational-gradient study focused on the thermal ecology and evolution of 22 species of land-breeding frogs, which are also known as terrestrial-breeding frogs, in southern Peru's Manu National Park and surrounding areas. Sampled elevations ranged from the Amazon River floodplain, at 820 feet above sea level, to 12,000-foot Andes Mountains peaks.

The region in and around Manu National Park is known for long-held records of biodiversity including more than 1,000 species of birds -- about 10 percent of the world's bird species -- and more than 1,200 species of butterflies. In addition, the park contains an estimated 2.2 percent of the world's amphibians and 1.5 percent of its reptiles.

While most frogs lay eggs in water, terrestrial-breeding frogs use a specialized reproductive mode called direct development: A clutch of embryos hatch directly into froglets; there are no free-living tadpoles. Terrestrial-breeding frogs form a diverse group that can exploit a wide variety of habitats, as long as those locations contain sufficient moisture.

In the study, the researchers looked at how closely related frog species differ in their elevational distribution and their tolerance to heat and cold in a region of the tropical Andes where temperature increase is predicted to be detrimental for most species.

"These measurements were taken in order to determine whether tropical frogs could take the heat -- or cold -- predicted for tropical regions as a result of climate change," von May said.

The researchers found that the frogs' tolerance to heat varied from 77 degrees Fahrenheit to 95 degrees and that, as expected, highland species tolerated much lower temperatures than lowland species.

Frogs living in high-elevation grasslands tolerated near-freezing temperatures, which they experience during the dry season, as well as moderately high temperatures, which they may experience during sunny days.

When considering the temperature of the microhabitats in which the frogs live, the results suggest tropical lowland species live close to their thermal limit. Amphibians living at high elevation might be more buffered from future temperature increases because the highest temperatures they can tolerate are farther away from the maximum temperatures that they regularly experience in the wild.

Von May is the first author of the Ecology and Evolution paper, "Divergence of thermal physiological traits in terrestrial breeding frogs along a tropical elevational gradient."

Citation
Rudolf von May, Alessandro Catenazzi, Ammon Corl, Roy Santa-Cruz, Ana Carolina Carnaval, Craig Moritz. Divergence of thermal physiological traits in terrestrial breeding frogs along a tropical elevational gradient. Ecology and Evolution, 2017; DOI: 10.1002/ece3.2929