Sternotherus

Number of Pages: 2Integrative BiologyGeological Science

Lepidochelys kempii

Number of Pages: 8Integrative BiologyGeological Science

Age and growth of Hawaiian seaturtles (Chelonia mydas): an analysis based on skeletochronology

Skeletochronological data on growth changes in humerus diameter were used to estimate the age of Hawaiian green seaturtles ranging from 28.7 to 96.0 cm straight carapace length. Two age estimation methods, correction factor and spline integration, were compared, giving age estimates ranging from 4.1 to 34.6 and from 3.3 to 49.4 yr, respectively, for the sample data. Mean growth rates of Hawaiian green seaturtles are 4–5 cm/yr in early juveniles, decline to a relatively constant rate of about 2 cm/yr by age 10 yr, then decline again to less than 1 cm/yr as turtles near age 30 yr. On average, age estimates from the two techniques differed by just a few years for juvenile turtles, but by wider margins for mature turtles. The spline-integration method models the curvilinear relationship between humerus diameter and the width of periosteal growth increments within the humerus, and offers several advantages over the correction-factor approach

Population Genetic Structure of Aldabra Giant Tortoises

Evolution of population structure on islands is the result of physical processes linked to volcanism, orogenic events, changes in sea level, as well as habitat variation. We assessed patterns of genetic structure in the giant tortoise of the Aldabra atoll, where previous ecological studies suggested population subdivisions as a result of landscape discontinuity due to unsuitable habitat and island separation. Analysis of mitochondrial DNA (mtDNA) control region sequences and allelic variation at 8 microsatellite loci were conducted on tortoises sampled in 3 locations on the 2 major islands of Aldabra. We found no variation in mtDNA sequences. This pattern corroborated earlier work supporting the occurrence of a founding event during the last interglacial period and a further reduction in genetic variability during historical time. On the other hand, significant population structure recorded at nuclear loci suggested allopatric divergence possibly due to geographical barriers among islands and ecological partitions hindering tortoise movements within islands. This is the first attempt to study the population genetics of Aldabra tortoises, which are now at carrying capacity in an isolated terrestrial ecosystem where ecological factors appear to have a strong influence on population dynamic

Biogeographic anomaly or human introduction: A cryptogenic population of tree skink (Reptilia: Squamata) from the Cook Islands, Oceania

Archaeological and molecular data have revealed that the present day faunas of many island groups in Melanesia, Polynesia, and Micronesia are not representative of the biodiversity generated within this region on an evolutionary timescale. Erroneous inferences regarding the mechanisms of speciation and the significance of long distance dispersal in shaping the present diversity of these island systems have resulted from this incomplete diversity and distributional data. The lizard fauna east of Samoa has been suggested to derive entirely from human-mediated introductions, a distribution congruent with biogeographic patterns for other Pacific species. Distinguishing between introduced populations and those that result from natural colonization events is difficult, although molecular data provide a useful means for elucidating population history and identifying the likely sources of introductions. We use molecular data (1726 bp of mitochondrial DNA and 286 bp of nuclear DNA) to evaluate a population of arboreal lizards from the Cook Islands and to determine whether this arboreal skink population is the sole endemic component of the lizard fauna east of Samoa or the result of human-mediated introduction. © 2010 The Linnean Society of London

Filling the BINs of life: Report of an amphibian and reptile survey of the Tanintharyi (Tenasserim) Region of Myanmar, with DNA barcode data

Despite threats of species extinctions, taxonomic crises, and technological advances in genomics and natural history database informatics, we are still distant from cataloguing all of the species of life on earth. Amphibians and reptiles are no exceptions; in fact new species are described nearly every day and many species face possible extinction. The number of described species continues to climb as new areas of the world are explored and as species complexes are examined more thoroughly. The use of DNA barcoding provides a mechanism for rapidly estimating the number of species at a given site and has the potential to record all of the species of life on Earth. Though DNA barcoding has its caveats, it can be useful to estimate the number of species in a more systematic and efficient manner, to be followed in combination with more traditional, morphology-based identifications and species descriptions. Herein, we report the results of a voucher-based herpetological expedition to the Tanintharyi (Tenasserim) Region of Myanmar, enhanced with DNA barcode data. Our main surveys took place in the currently proposed Tanintharyi National Park. We combine our results with photographs and observational data from the Chaung-naukpyan forest reserve. Additionally, we provide the first checklist of amphibians and reptiles of the region, with species based on the literature and museum. Amphibians, anurans in particular, are one of the most poorly known groups of vertebrates in terms of taxonomy and the number of known species, particularly in Southeast Asia. Our rapid-assessment program combined with DNA barcoding and use of Barcode Index Numbers (BINs) of voucher specimens reveals the depth of taxonomic diversity in the southern Tanintharyi herpetofauna even though only a third of the potential amphibians and reptiles were seen. A total of 51 putative species (one caecilian, 25 frogs, 13 lizards, 10 snakes, and two turtles) were detected, several of which represent potentially undescribed species. Several of these species were detected by DNA barcode data alone. Furthermore, five species were recorded for the first time in Myanmar, two amphibians (Ichthyophis cf. kohtaoensis and Chalcorana eschatia) and three snakes (Ahaetulla mycterizans, Boiga dendrophila, and Boiga drapiezii)

The conservation status of the world’s reptiles

MB and MR were funded by a grant from the Esmee Fairbairn Foundation, BC by the Rufford Foundation. North American and Mexican species assessments were funded by the Regina Bauer Frankenberg Foundation for Animal Welfare. Species assessments under the Global Reptile Assessment (GRA) initiative are supported by: Moore Family Foundation, Gordon and Betty Moore Foundation, Conservation International, Critical Ecosystem Partnership Fund (CEPF), and European Commission. Additional acknowledgements are included in the online supplementary material. The assessment workshop for Mexican reptiles was kindly hosted by Ricardo Ayala and the station personnel of the Estacion de Biologia Chamela, Institut de Biologia, Universidad Nacional Autonoma de Mexico. Workshop and logistical organisation of the Philippines assessments was provided by the Conservation International Philippines Office, in particular Ruth Grace Rose Ambal, Melizar V. Duya and Oliver Coroza. Workshop and logistical organisation for the European Reptile and Amphibian Assessments was provided by Doga Dernegi, in particular Ozge Balkiz and Ozgur Koc. Workshop and logistical organisation for assessments of sea snakes and homalopsids was provided by the International Sea Turtle Symposium and Dr. Colin Limpus (Australian Government Environmental Protection Agency). Special thanks to Jenny Chapman (EPA) and Chloe Schaub le (ISTS). Thank you also to Dr. Gordon Guymer (Chief Botanist Director of Herbarium) for accommodating us at the Herbarium in the Brisbane Botanical Gardens, and Mark Read and Kirsten Dobbs (Great Barrier Reef Marine Parks Association) and Dave Pollard and Brad Warren (Ocean Watch Australia) for institutional support. Mohamed Bin Zayed Species Conservation Fund, Conservation International Madagascar and the Darwin Initiative contributed to funding the costs of the Madagascar reptile workshop.Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of human-induced habitat loss and harvesting, which are the predominant threats to reptiles.Esmee Fairbairn FoundationRufford FoundationRegina Bauer Frankenberg Foundation for Animal WelfareMoore Family FoundationGordon and Betty Moore FoundationConservation International, Critical Ecosystem Partnership Fund (CEPF)European Commission Joint Research CentreZayed Species Conservation FundConservation International MadagascarDarwin Initiativ

Striped Skinks in Oceania: The Status of Emoia caeruleocauda in Fiji

A rediscovered population of Emoia caeruleocauda from the Fiji Islands is compared with populations from Papua New Guinea, the Caroline Islands, and Vanuatu. Morphometrically, females from all populations are somewhat smaller than males, although males are significantly larger only in head length and width, and hindlimb length. Females and males do not appear dimorphic in scalation. Interpopulation comparison shows the populations to differ from one another in morphometry and scalation. In morphometry females and in scalation males and females of Fiji and Vanuatu and those of the Carolines and Papua are more similar to one another than each member of a pair is to members of the other pair. These patterns of variation suggest that the Fijian population of E. caeruleocauda is a native one and not introduced

Recent Records of Exotic Reptiles on Pohnpei, Eastern Caroline Islands, Micronesia

Seven nonindigenous species of reptiles (two freshwater turtles, one gekkonid lizard, and four snakes) were recorded on Pohnpei and adjacent Ant Atoll (Federated States of Micronesia) for the first time within the past 15 yr, three within the past 3 yr. They apparently reached Pohnpei by deliberate or inadvertent human-assisted transport, originating from widespread and distant areas including North America, Southeast Asia, Indoaustralia, and other Pacific islands. Pohnpeians (and many other Pacific islanders) often do not perceive exotics as a potential threat to the balance of natural ecosystems. Additional training and education addressing the potentially disastrous consequences of alien species and directed especially toward agencies entrusted with monitoring environmental quality are recommended to help preserve biodiversity on these small island nations