Telmatobius carrillae Morales, 1988, is a riparian frog inhabiting an altitudinal range of 3,680–4,718 m asl in the Central Peruvian Andes. Snout–vent length at metamorphosis is 21.6 mm; minimum size at maturity is 35.3 mm in males and 40.0 mm in females; and maximum size recorded 53.5 mm and 60 mm, respectively. Variation in size is accounted for by pronounced sexual size dimorphism and sex-independent increase in size along an altitudinal gradient (Bergmann cline). Dorsal and ventral color pattern varies considerably from locality to locality rendering this character unreliable for species diagnosis. Most skin features (e.g., width of skin layers, gland size and frequency) showed a considerable range of covariation with ontogenetic stage, sex, and SVL. The absence of serous glands with large granules, a character state shared with Batrachophrynus spp., is confirmed for T. carrillae. However, analysis of the altitudinal ranges of telmatobiine frogs with and without serous glands with large granules suggests that the apparent synapomorphy of Batrachophrynus spp., and T. carrillae may alternatively constitute a response to the ecological demands of high-altitude habitats rather than a phylogenetic signal.

Physiological color change and geographic variation in coloration are well documented in several squamate lineages, having presumably evolved for cryptic, sexual signaling, and thermoregulatory functions. Only 11 snake species have demonstrated physiological color change, although anecdotal reports suggest it may be present in additional species. We describe color variation and physiological color change in island and mainland populations of Boa constrictor using full-spectrum reflectance spectrometry. We employed principal components analysis (PCA) summarizing the spectrometry data into two axes that describe the brightness (PC1) and chroma or relative intensity of particular wavelengths (PC2). Boas from island and mainland localities exhibited physiological color change, and this change occurred on a diel cycle. Boas from both locations were lighter at night and darker during the day. The magnitude of the color change differed between our two PC axes. Although change in brightness was similar for boas on the islands and the mainland, the change in chroma was greater in boas from the mainland. Color also varied seasonally; boas were lighter in color and reflected more long-wavelength light during the wet season than during the dry season in Belize. We suggest that a fundamental hormone cycle (melatonin/melanophore stimulating hormone, MSH) present in a wide variety of vertebrates, underlies the physiological color change in snakes. If this is true, color change may be more widespread than previously realized, and the perceptual bias of the human vision system may have caused researchers to discount its presence in snakes.

We describe a new species of the rostrata species group of Bolitoglossa (Magnadigita) from a single cloud forest site on the south slope of the Sierra de las Minas in eastern Guatemala, an area of high biodiversity for many groups of organisms. This species is distinguished from other members of the subgenus on the basis of morphology and molecular analyses, and it differs from the sympatric Bolitoglossa helmrichi in ventral coloration of the tail and in foot and body morphology.

The Pratt Slide fossil site of Brown County, Nebraska, has yielded the largest and most diverse Clarendonian North American Land Mammal Age (late Miocene; approximately 10.5–9.5 Ma) snake fauna thus far known. The overall composition of the snake fauna consists of extinct taxa from older Miocene times, temporally isolated taxa, and modern taxa. More specifically, the fauna includes at least two extinct erycine boids, 14 colubrids of which five genera are extinct, and possibly three extant viperid genera. The fossil site yielded additional evidence (three vertebrae) of the unique late Clarendonian erycine Tregophis brevirachis and vertebrae of a new distinctive tiny natricine colubrid. Additional vertebrae of a Paleoheterodon–Heterodon snake(s) further support the suggestions by others that these two xenodontine colubrids are indistinguishable at the vertebral level. Overall, the composition of the Pratt Slide snake fauna provides supportive evidence of a North American late Miocene transition from an archaic to a modern snake fauna with most of the modernization taking place during Clarendonian to Hemphillian time (approximately 10–6 Ma).

The turtle genus Graptemys consists of 15 recognized taxa, distinguished largely on the basis of pigmentation pattern (i.e., soft tissue and shell), head size, and shell morphology. However, phylogenetic studies have shown limited sequence divergence within the genus and between Graptemys oculifera and Graptemys flavimaculata relative to most other members of the Emydidae. Graptemys oculifera of the Pearl River drainage and G. flavimaculata of the Pascagoula River drainage have been recognized as species since 1890 and 1954, respectively. However, the description of G. flavimaculata was based on a limited number of morphological characters. Several of these characters overlap between G. flavimaculata and G. oculifera, and no attempt was made to test for significant morphological differentiation. In this study, we reevaluated the morphological and genetic distinctiveness of G. flavimaculata and G. oculifera with (1) multivariate statistical analyses of 44 morphological characters and (2) 1,560 bp of sequence data from two mitochondrial genes (control region and ND4). The morphological and molecular analyses produced incongruent results. The principal components analysis ordinations separated the two species along a pigmentation gradient with G. flavimaculata having more yellow pigmentation than G. oculifera. Likewise, clustering analyses separated the specimens into two distinct groups with little overlap between the species. Our mitochondrial data supported previous findings of limited genetic differentiation between the two species. However, the results of our morphological analyses, in conjunction with recently published nuclear gene sequence data, support the continued recognition of the two species.

A new scansorial species of Cophixalus is described from lower montane mossy rain forest in the Moro and Moran areas of Southern Highlands Province in Papua New Guinea. It can be distinguished from all other Cophixalus species in New Guinea by the combination of relatively small size (15.2–19.2 mm snout–vent [SVL]; N  =  10), possession of a single distinct spiniform tubercle on the upper eyelid and a series of spiniform tubercles on the hind limb, tuberculate skin, well developed discs on all digits except the first finger, absence of distinct brown or back lateral markings on the head, and a call consisting of 26–33 musical peeping notes.

The nominate subspecies of Slater's Skink, Egernia slateri, is nationally endangered with a severely restricted range on desert river floodplains in central Australia. Here, we provide the first details of foraging ecology and habitat use of one of the remaining wild populations. Ants (35.0% volume, 95.5% occurrence) and termites (Isoptera, 23.3% volume, 63.6% occurrence) were the major prey of adult E. slateri. Other important prey included Coleoptera, Orthoptera, and spiders. Egernia slateri depended on soil mounds formed at the base of shrubs as habitat in which to dig burrows. Ninety-five percent of shrubs in the genus Eremophila sampled in two subpopulations were mounded and 58% of the mounded shrubs had lizard burrows. Behavioral observations indicate that E. slateri is largely solitary with a group size of one (94% of bouts), except for three observations of adult–juvenile associations. Animals showed diurnal activity with basking individuals present up to 327 min postsunrise. The study reveals E. slateri as a species occurring in small populations in limited habitat. It faces imminent threats to its persistence as a result of high disturbance regimes on floodplains in central Australia and is considered one of Australia's most threatened reptiles.

Solar ultraviolet radiation (UV) has received much attention as a factor that could play a role in amphibian population declines. UV can be hazardous to some amphibians, but the resultant effects depend on a variety of environmental and behavioral factors. In this study, the potential effects of UV on the Northwestern Salamander, Ambystoma gracile, from three lakes were assessed in the laboratory using a solar simulator. We measured the survival of embryos and the survival and growth of larvae exposed to four UV treatments in controlled laboratory studies, the UV absorbance of egg jelly, oviposition depths in the lakes, and UV absorbance in water samples from the three lakes. Hatching success of embryos decreased in the higher UV treatments as compared to the control treatments, and growth of surviving larvae was significantly reduced in the higher UVB irradiance treatments. The egg jelly exhibited a small peak of absorbance within the UVB range (290–320 nm). The magnitude of UV absorbance differed among egg jellies from the three lakes. Oviposition depths at the three sites averaged 1.10 m below the water surface. Approximately 66% of surface UVB radiation was attenuated at 10-cm depth in all three lakes. Results of this study indicate that larvae may be sensitive to UVB exposure under laboratory conditions; however, in field conditions the depths of egg deposition in the lakes, absorbance of UV radiation by the water column, and the potential for behavioral adjustments may mitigate severe effects of UV radiation.

We examined Desert Tortoise microhabitat selection on the Florence Military Reservation (FMR) in south-central Arizona where National Guard training and other activities, such as motorized recreation and grazing, are permitted. Previous research on the FMR indicated that Desert Tortoise home ranges overlapped with firing boxes, areas where most of the National Guard's training activity was concentrated. Our objective was to examine Desert Tortoise microhabitat selection within, and adjacent to, these firing boxes in an effort to guide future management for restoring degraded tortoise habitat on the installation. Desert Tortoises selected habitat that was characterized by a higher percentage of canopy cover, absence of cattle activity, and closer proximity to roads and washes than was available within their home range. Canopy cover had the highest calculated parameter importance and was included in each of the supported microhabitat selection models. Areas with sufficient canopy cover most likely provided shade for escaping the desert heat during periods of high tortoise activity. Our results suggest that management prescriptions that maintain, or increase, the amount of vegetative cover and that protect desert washes will have positive impacts on Desert Tortoise populations.

Worldwide amphibian population declines have occurred in the last few decades and have been attributed to a range of factors including introduced species and chemical contamination. Anuran species may differ in their susceptibility to declines based on life-history characteristics, leading to different probabilities of decline and conservation statuses. In this experiment, we looked at two anuran species, Northern Cricket Frogs (Acris crepitans) and Green Frogs (Rana clamitans), reared in mesocosms containing a common invasive or introduced potential predator (Rusty Crayfish, Bluegill Sunfish, or triploid Grass Carp) and imidacloprid, a common insecticide. We found that anurans differed in their sensitivity to these factors. Cricket Frog survival was significantly reduced with imidacloprid exposure, whereas Green Frogs were not. Abundance of both amphibian species was reduced in the presence of predators, particularly the fish. Our study suggests that Cricket Frogs may be especially sensitive to the insecticide imidacloprid, as well as fish predators, and that these factors could contribute to their population declines.

Phenotypic variation in a population is a key requirement for natural selection. Body size variation, in particular, can affect the dynamics, life history, and ecological relationships in a population. Past work suggests that variation in body size within a population reflects a competitive gradient in which larger individuals negatively affect smaller individuals because of the superior ability to obtain limited resources, a result of exploitative or interference competition. We hypothesized that, if larger individuals out-compete smaller individuals through aggressive interactions (interference competition), the individual's position in the size distribution of their population (relative size) would be a better predictor of growth rate and time to metamorphosis than would their absolute size. We tested for the effect of body size on future larval growth rates, time to metamorphosis, and aggressive behaviors in individual Ambystoma talpoideum using experimental microcosms. Larvae were reared in small groups, producing variation in growth and development within each group. Using mixed-model analyses, we found that relative size was the best predictor of time to metamorphosis and aggressive behaviors and that growth rate of individuals within these populations was best explained by absolute or relative size depending on life stage. The largest individuals within a tank made the most aggressive attacks, had faster growth rates when young, and the quickest time to metamorphosis, regardless of their absolute size. This study found evidence for a complex relationship between population size structure, growth rate, and time to metamorphosis by tracking the effects of relative size on individuals within a population.

A new endemic species of gymnophthalmid lizard of the genus Riama is described from the Cordillera Occidental of northern Colombia. The new species differs from all known Riama by pholidosis, hemipenial morphology, and color pattern. The four known endemic Colombian species, Riama columbiana, Riama laevis, Riama stellae, and Riama striata, occur in different montane forests and are not known to be sympatric with the new species. The new species most resembles R. laevis from the Cordillera Occidental of the Colombian Andes, but it differs in having 15 longitudinal scale rows, 21–23 transverse scale rows in males and 22 in females, and limbs that do not overlap or just touch when adpressed against the body.

Efficient deployment of culverts to mitigate mortality of amphibians on roadways requires identification of locations within road networks where animals cross (hotspots), points within identified hotspots for culvert placement, and attributes of culverts that make them behaviorally palatable to migrating individuals. In this study, we assessed road crossing frequency of Spotted Salamanders, Ambystoma maculatum, and American Toads, Anaxyrus americanus, along a 700-m transect within a known crossing hotspot, and related these distributions to habitat variables within the hotspot including the presence of existing culverts. We also placed experimental arrays of culverts of varying attributes in the path of migrating Spotted Salamanders to examine culvert preference by salamanders under typical movement environments and appropriate animal behavioral states. Our studies of patterns of road occurrence demonstrated that both species avoided crossing where there was a wetland within 15 m of the downslope of the road and that neither species showed a strong preference for crossing near existing culverts. When considering the choice for experimental culverts by Spotted Salamanders, we found no preference for culverts of varying aperture size, length, or substrate. Our results indicate that patterns of occurrences of the two species of amphibian within a crossing hotspot may be linked to the physical attributes at the site. For Spotted Salamanders in particular, predicting where they will cross within a hotspot may not be easy. Spotted Salamanders showed little preference for culverts of different design, indicating that a variety of culvert designs can suffice for mitigation if placed in appropriate locations.

Distasteful, noxious, and toxic secretions from skin glands have been demonstrated to play important antipredatory roles in amphibians. Previous studies suggest that the Long-toed Salamander (Ambystoma macrodactylum), a widely distributed urodele found near the northern limit of its range in northern British Columbia, is distasteful to predators. The source of this distastefulness has not been exclusively identified. Our objectives were to isolate the skin secretions of the Long-toed Salamander through electrical stimulation of its granular glands and bioassay this secretion for antipredatory effects with crayfish. Previous studies suggested that proteins play an important role in these secretions; therefore, we tested for their presence and utility. The feeding response of crayfish to control food pellets was compared to pellets incorporating raw salamander skin secretions and to pellets incorporating boiled secretions. Significantly more crayfish consumed the control pellets than the raw skin secretion pellets, indicating unpalatability of these skin secretions. Thus, skin secretions appear to have an important antipredatory function. Skin secretions tested positive for presence of proteins, but the feeding response of crayfish to raw and boiled secretions was not significantly different, indicating that proteins were either only partially denatured by boiling, or are not exclusively responsible for the antipredatory nature of the secretions. A very low concentration of secretion was required to illicit a significant antifeedant response in crayfish, and we discuss the possible implications of this in relation to a proposed dual function of the Long-toed Salamander's granular glands in nutrient storage and the energetic requirements of an amphibian in its northern range.

We examined the influence of reduced hemoglobin concentrations resulting from malarial infection on metabolism and thermoregulation in the Fence Lizard, Sceloporus occidentalis. Malarial infections diminish the oxygen-carrying capacity of the blood, depressing hemoglobin concentrations by as much as 25%. Lizards collected from Oregon were screened for Plasmodium mexicanum. Malaria-infected and uninfected lizards were placed on a temperature-controlled treadmill at preferred body temperature (35°C) and induced to walk at constant speed for 5 min (0.7 m min⁻¹) or sprint maximally to exhaustion (<2 min of activity). Excess oxygen consumption during recovery was over 30% higher in infected lizards when compared to uninfected lizards following similar levels of activity. Malarial infection significantly elevated blood lactate levels following sprint or endurance activity (20 and 36% elevation, respectively) when compared to uninfected lizards. Malarial infection significantly increased preferred body temperature tested in a thermal gradient following sustained activity (2–4°C increase) but had little impact on thermoregulation following exhaustive exercise. There was a strong negative correlation between hemoglobin concentration and postactivity body temperature. Our findings suggest that there are metabolic costs, measured as excess oxygen consumption and thermoregulation disruptions, associated with malaria-induced hemoglobin depression. These results may help explain limited size and reproductive success previously measured in malaria-infected lizards.

A recent study showed that populations of the threatened Florida Sand Skink had limited loss of genetic diversity over the past 60 yr as a consequence of anthropogenic fragmentation. This study assumed that 60 yr represents 30–37 generations for the Florida Sand Skink, but a new evaluation of mark–recapture data shows that 60 yr represents only about 15 generations. This result suggests that too little time may have passed to observe the full genetic consequences of contemporary anthropogenic fragmentation in the Florida Sand Skink and reinforces similar results from other species. We suggest that snapshots of existing genetic variability in fragmented populations are limited in their ability to predict the evolutionary fate of a species unless life-history attributes of the organism are taken into account.

Flexibility can be important in male–female behavioral interactions, particularly during courtship when a male typically adjusts his behavior in response to the female. Red-legged Salamanders (Plethodon shermani) have highly stereotyped courtship behaviors but show flexibility in the repetition of particular behaviors. We tested one measure of flexibility in a specific male courtship behavior: pheromone delivery. We compared the number of male pheromone delivery attempts that occurred when a male “slapped” his pheromone-producing mental gland on the female's nares. We compiled a multiyear data set from earlier experiments on salamander behavior to test the consistency in the number of slaps each male delivered in two different courtships. The consistency level was 26% (26% of the total deviance in slapping behavior could be explained by previous slapping behavior), a value within the range of measures for other vertebrate behavioral traits. We interpret this consistency as a possible advantage to the male in delivering sufficient pheromone such that the female will not abandon the male during the critical process of sperm transfer.

Posthatching parental care is known in amphibians for frogs and caecilians but, thus far, has never been reported for salamanders. Here, we describe the parental behavior of a female Northwest Italian Cave Salamander, Speleomantes strinatii, from egg deposition to nest site abandonment. The female was kept in seminatural conditions and filmed in complete darkness by an infrared video camera. In November 2007, the female laid nine eggs in a small depression of the terrarium floor, displaced the clutch with hind limbs, and showed antipredator behaviors toward a conspecific female and an intruding Roof Rat (Rattus rattus). During egg brooding, the female remained in contact with the clutch for about 98% of the time. In September 2008, two young hatched and shared the nesting site for six weeks with the female, which attended the nesting site for 87% of the time. Hatchlings repeatedly climbed over the female's body, lying on her for hours. The female walked out of the nesting site with a young on its back twice. These prolonged skin contacts between parent and offspring should be considered as the first certain case of young attendance in salamanders. This behavior may be related to increased survival of hatchlings during their first weeks of life, when young are particularly vulnerable to predation, skin infection, and dehydration.

Advertisement calls of the West Australian frogs Crinia pseudinsignifera and Crinia subinsignifera are distinct. I report a natural hybrid between C. subinsignifera and C. pseudinsignifera based on initial detection of an intermediate call and confirmed by allozyme data. I discuss patterns of hybridization among C. subinsignifera, C. pseudinsignifera, and Crinia insignifera.

Nesting sites of three species of turtles, Trachemys dorbignyi, Phrynops hilarii, and Hydromedusa tectifera, were analyzed from 1997 to 2002 at the Taim Ecological Station, in the southern Brazil. Our objective was to evaluate the size of the core habitat necessary to protect nesting sites of these species and to relate this information to Brazilian environmental legislation. Trachemys dorbignyi and P. hilarii have similar width of their nesting sites, 49.6 ± 36.3 m and 50.5 ± 30.4 m, respectively. Hydromedusa tectifera lays its eggs closer to the edge of waterbodies, on average at 12.6 ± 10.0 m. Curves were constructed to define the widths of the core habitats needed to protect 90% of the nests of each species. Trachemys dorbignyi requires 94 m of terrestrial habitat from the edge of waterbodies, P. hilarii requires 79 m and H. tectifera 24 m. In the study area, Brazilian legislation establishes a core habitat that is sufficient to protect the nests of these species around large waterbodies. However, because the protection areas are prescribed according to the width of the aquatic environments, this provision is insufficient for the majority of the aquatic environments in the region.