New reptiles and stegocephalians from the Upper Triassic of western Texas.

"The literature of the Triassic vertebrates of North America": p. 12.

Pictorial keys to arthropods, reptiles, birds, and mammals of public health significance.

"Previously issued under the same title by the Centers of Disease Control and PRevention of the U. S. Public Health Service, Atlanta, Georgia"--t.p. verso.

A check list of North American amphibians and reptiles,

Mode of access: Internet.

Physiological mechanisms of thermoregulation in reptiles: a review

The thermal dependence of biochemical reaction rates means that many animals regulate their body temperature so that fluctuations in body temperature are small compared to environmental temperature fluctuations. Thermoregulation is a complex process that involves sensing of the environment, and subsequent processing of the environmental information. We suggest that the physiological mechanisms that facilitate thermoregulation transcend phylogenetic boundaries. Reptiles are primarily used as model organisms for ecological and evolutionary research and, unlike in mammals, the physiological basis of many aspects in thermoregulation remains obscure. Here, we review recent research on regulation of body temperature, thermoreception, body temperature set-points, and cardiovascular control of heating and cooling in reptiles. The aim of this review is to place physiological thermoregulation of reptiles in a wider phylogenetic context. Future research on reptilian thermoregulation should focus on the pathways that connect peripheral sensing to central processing which will ultimately lead to the thermoregulatory response.

Influence of incubation temperature on hatchling phenotype in reptiles

Incubation temperature influences hatchling phenotypes such as sex, size, shape, color, behavior, and locomotor performance in many reptiles, and there is growing concern that global warming might adversely affect reptile populations by altering frequencies of hatchling phenotypes. Here I overview a recent theoretical model used to predict hatchling sex of reptiles with temperature-dependent sex determination. This model predicts that sex ratios will be fairly robust to moderate global warming as long as eggs experience substantial daily cyclic fluctuations in incubation temperatures so that embryos are exposed to temperatures that inhibit embryonic development for part of the day. I also review studies that examine the influence of incubation temperature on posthatch locomotion performance and growth because these are the traits that are likely to have the greatest effect on hatchling fitness. The majority of these studies used artificial constant-temperature incubation, but some have addressed fluctuating incubation temperature regimes. Although the number of studies is small, it appears that fluctuating temperatures may enhance hatchling locomotor performance. This finding should not be surprising, given that the majority of natural reptile nests are relatively shallow and therefore experience daily fluctuations in incubation temperature.

Temperature and the respiratory properties of whole blood in two reptiles, Pogona barbata and Emydura signata

We investigated the capacity of two reptiles, an agamid lizard Pogona barbata and a chelid turtle Emydura signata, to compensate for the effects of temperature by making changes in their whole blood respiratory properties. This was accomplished by measuring the P-50 (at 10, 20 and 30 degrees C), hematocrit (Hct), haemoglobin concentration ([Hb]) and mean cell haemoglobin concentration (MCHC) in field acclimatised and laboratory acclimated individuals. The acute effect of temperature on P50 in P barbata, expressed as heat of oxygenation (Delta H), ranged from -16.8 +/- 1.84 to -28.5 +/- 2.73 kJ/mole. P-50 of field acclimatised P barbata increased significantly from early spring to summer at the test temperatures of 20 degrees C (43.1 +/- 1.2 to 48.8 +/- 2.1 mmHg) and 30 degrees C (54.7 +/- 1.2 to 65.2 +/- 2.3 mmHg), but showed no acclimation under laboratory conditions. For E. signata, Delta H ranged from -31.1 +/- 6.32 to -48.2 +/- 3.59 kJ/mole. Field acclimatisation and laboratory acclimation of P-50 did not occur. However, in E. signata, there was a significant increase in [Hb] and MCHC from early spring to summer in turtles collected from the wild (1.0 +/- 0.1 to 1.7 +/- 0.2 mmol/L and 4.0 +/- 0.3 to 6.7 +/- 0.7 mmol/L, respectively). (C) 2005 Published by Elsevier Inc.

Distribution and ecology of amphibians and reptiles in a fragmented landscape, northeastern Bolivia

Habitat loss and fragmentation have been implicated as driving forces behind recent waves of extinction. The regional landscape where this study occurred is a mosaic of forest and grassland, and therefore provides an ideal system with which to investigate the implications of habitat patchiness for the distribution and ecology of organisms. Here I describe patterns of amphibian and reptile distribution among and within habitats at the study site, investigate associations between habitat and community structure, describe nested subset patterns on forest islands, and quantify the relationship between body size and density across ecological scales and taxonomic groups. ^ Species richness did not vary across habitats, between forest island isolation classes or between island edges and cores. In contrast, species composition varied at all three ecological scales, reflecting differences in the distribution of both forest and open-habitat affiliated species. Species composition was associated with multivariate habitat profiles, with differences occurring along the isolation gradient of forest islands rather than the area gradient. The relationship between species composition and habitat was stronger for amphibians than for reptiles, a pattern that may be ascribed to physiological differences between the two groups. Analysis of nested subset pattern of community structure indicated that species composition of islands is nested as a function of isolation. Four species whose distribution on forest islands seems to be dispersal-limited drive the relationship between nestedness and isolation. Although there were several examples of shifts in body size across spatial scales and taxonomic groups, body size was not associated with density as predicted by theory, which may reflect differences between real and habitat islands, or differential responses of poikilothermic vertebrates to changes in density relative to homeotherms. ^ Taken together, the strongest result to emerge from this research is the importance of isolation, rather than area, on community structure in this system. Much evidence suggested that different ecological groups of species show distinct patterns of distribution both within and among habitat types. This suggests that species distributions at this site are not the result of 'neutral' processes at the community level, but rather reflect fundamental differences in the ecology of component species. ^

Conservation ecology of amphibians and reptiles in Sarapiqui, Costa Rica : forest fragmentation and long term population change

In order to explore the conservation ecology of frogs and lizards in the Sarapiqui region of Costa Rica, I compared populations and communities among forest fragments and La Selva Biological Station, as well as across 35 years of sampling at La Selva. Species richness in nine fragments combined was 85% of that found in La Selva, and community composition varied among sites and by fragment size class. Although communities in fragments differed fundamentally from those in intact forest, the high diversity observed across all fragments indicates that preserving a network of small forest patches may be of great conservation value to the herpetofauna of this region. According to data from past studies at La Selva, most common species of leaf-litter frogs and lizards demonstrated significant decreases in density over the 35-year period. My findings may represent either natural population fluctuations or sweeping faunal declines at this site.

Los anfibios y reptiles naturalizados en España: historia y evolución de una problemática creciente. Historia y evolución de una problemática creciente

[ES] No es una novedad que muchas especies ocupen áreas de las que no se las considera originarias y que, en un porcentaje elevadísimo de los casos, la mano del hombre se encuentre directamente detrás de esos movimientos de animales y plantas. Pero la gravedad del problema se ha incrementado hasta tal punto que en la actualidad se la considera uno de los principales azotes medioambientales y la segunda causa probada de pérdida de biodiversidad a nivel global (Lowe et al., 2000; IUCN, 2010). Muchas de las que han sido calificadas como las peores especies invasoras han acompañado al hombre en sus correrías desde los albores de la historia, aclimatándose a las condiciones del nuevo territorio y provocando la extinción de numerosas especies nativas e incluso modificando el paisaje (Lowe et al., 2000).

Los reptiles de la Isla de Boavista (archipiélago de Cabo Verde)

[ES] Boavista, o Bubista como prefieren escribir sus habitantes, es la isla más oriental del archipiélago volcánico de Cabo Verde con 620 km2 de superficie. Su antiguo origen se ve reflejado en una geografía extremadamente erosionada y plana, en la que no se sobrepasan los 390 metros sobre el nivel del mar. Soporta un clima extremadamente árido (precipitaciones: 91 mm media anual), con temperaturas suaves (Tmax = 26.7ºC; Tmin = 21.4ºC) y con la presencia casi constante de los vientos del nordeste (Alisios) (KASPER, 1987). La vegetación es esteparia, rala y generalmente 10 desprovista de estrato arbóreo, con la salvedad de algunas áreas localizadas (CASTANHEIRA & CARDOSO, 1988).

Nueve especies nuevas de reptiles y anfibios descubiertos en El Salvador

Durante la segunda mitad del año 1950 el autor tuvo la posibilidad de estudiar, como el investigador huésped del Instituto Tropical de Investigaciones Científicas en El Salvador, los reptiles y anfibios de El Salvador. Su colección Herpetológica ha sido completa desde entonces, esencialmente, por las actividades del doctor Adolf también investigar huésped del mencionado Instituto durante el año 1951. Una obra bastante detenida acerca de todos los reptiles y anfibios coleccionados por nosotros en El Salvador; una fauna completa de los reptiles y anfibios Salvadoreños está siendo llevada casi a término. Aquí solo se trata de las nueve especies y subespecies nuevas de reptiles y anfibios Salvadoreños descubiertos, dando el autor sus definiciones exactas.