We compared reproduction, diet, and body size of Polychrus acutirostris (Squamata: Polychrotidae) from the Cerrado and Caatinga biomes in Brazil. Because these two biomes have widely different climates, we predicted that lizards in Caatinga would produce smaller clutches in response to rainfall unpredictability. We also expected reproductive timing to differ between biomes, with lizards occurring in the Cerrado producing a single clutch in association with the predictable rains of October–November. Contrary to expectations, clutches had fewer (although larger) eggs in Cerrado. Reproductive period was remarkably similar (peak of female reproductive activity in November), but female reproduction started 1 month earlier in Cerrado. Diet composition was also similar, with the exception of spiders, that exhibited a high index of relative importance in Cerrado but were nearly absent in Caatinga lizard diets. Lizards from both biomes ingested a large proportion of plant material, as well as soft-bodied arboreal arthropods, such as orthopterans, and mostly slow-moving, large arboreal insects. Rainfall predictability in the Cerrado therefore did not influence Polychrus reproduction or diet in the same manner as in other lizard species. The large number of small eggs in the Caatinga suggests that the competitive environment for offspring is either unpredictable or that mortality is high but random. Rain forest Polychrus lizards produce few large eggs, suggesting that the competitive environment for offspring is predictably intense and mortality is non-random. Cerrado Polychrus lizards seem intermediate between Caatinga and rain forest Polychrus lizards, producing fewer and larger eggs than their conspecifics in the Caatinga but relatively more and smaller eggs than rain forest Polychrus species.

We studied the reproduction, sexual dimorphism, and diet of Oxyrhopus trigeminus from two sites in southeastern Brazil. Oxyrhopus trigeminus from Irapé Power Plant (IPP) contained vitellogenic follicles and eggs in both rainy and dry seasons and clutch size was not correlated with female snout–vent length (SVL). Sexual dimorphism was evident. Females attain larger SVL but males have longer tails. We found three females from Santa Clara Power Plant (SPP) with vitellogenic follicles, all of them collected in the dry season. Mean SVLs of adult females from IPP and SPP were 717.7 mm and 786 mm, respectively. Mean SVL of adult males from IPP was 553.4 mm and the single adult male from SPP was 507 mm. The diet of O. trigeminus from IPP included rodents (46.7%), lizards (33.3%), and birds (20%). The volume of individual prey items was not correlated with snake SVL. The diet of O. trigeminus from SPP included rodents (37.5%), lizards (37.5%), birds (12.5%), and marsupials (12.5%). It seemed that an ontogenetic shift may occur in individuals of this snake species from IPP.

Chiasmocleis mantiqueira is a small microhylid frog recently described from an Atlantic rain forest fragment found in the state of Minas Gerais, southeastern Brazil, whose biology is poorly know. Here, the tadpole and the vocalizations of this species are described from the type locality, along with some information about its natural history. Characteristics of larval external morphology of C. mantiqueira are similar to other described tadpoles of the genus: oral disc without keratinized mouthparts, spiracle single, posterior ventral, and medial vent tube. The body is depressed, rectangular in dorsal view and oval in lateral view, and the tail has a flagellum. The species exhibits an explosive breeding behavior, like other Neotropical microhylids. However, unlike other species in this genus, males of C. mantiqueira do not have a vocal sac, and its call is composed of a single harmonic, not a pulsed, note. Thus, the characteristics of the call of C. mantiqueira contradict the hypothesis that call structure can support the monophyly of Chiasmocleis, and further data are required to clarify the relationship of the species in this genus.

This study explores the feeding ecology, habitat use, and fecundity of Phyllodytes luteolus inside bromeliads in the restinga of Regência (sandy coastal plain), Espírito Santo state, southeastern Brazil. Because bromeliads are harvested for commercial use, and frogs may be collected accidently, the ecology of this frog is of particular interest. We collected 363 individuals of P. luteolus (103 tadpoles, 74 juveniles, 64 males, and 122 females) from three species of bromeliads in a 4-km² area bimonthly from February to December of 1998. Ants and termites were the dominant food items in terms of number and mass over time. The percentage of prey items and the size of prey eaten by juveniles differed significantly from those of adults. Dominant prey items were relatively similar across the sampled bromeliad species and locations. Phyllodytes luteolus preferred Vriesea procera, the most-complex bromeliad in our study site. Half of the individuals were found in bromeliads located in transitional zones. Female P. luteolus were slightly larger than the males, which may have determined the strong sex ratio bias toward females. We found females with developed oocytes (range 11–15) in every sampled month, indicating a protracted spawning period. This frog can be considered an active forager and specialist, feeding preferentially on colonial insects. Phyllodytes luteolus uses several species of harvested bromeliads and possesses several attributes that could facilitate its success as an invasive species.

We present a cytogenetic survey of the basal bufonid genus Melanophryniscus that covered 14 of the 25 species currently recognized, representing the three phenetic species groups: M. moreirae, M. stelzneri, and M. tumifrons. All species presented a diploid chromosome complement constituted by 11 bi-armed chromosome pairs (2n  =  2x  =  22; FN  =  44). Some remarkable differences were observed between species groups: chromosome pair 4 was metacentric in species of the M. tumifrons group (also with a distinctive C-positive block) but submetacentric in the M. stelzneri group and M. sanmartini (M. moreirae group); pair 5 was submetacentric in M. sanmartini and metacentric in the rest. Chromosome secondary constrictions and silver-stained nucleolar organizer regions were located either in pair 5, 7, or 8 in the M. tumifrons group, M. sanmartini and M. krauczuki (M. stelzneri group), and M. stelzneri group, respectively; and pair 7 was relatively larger in M. sanmartini and M. krauczuki. Studied cytogenetic characters support the M. tumifrons group and suggest a close relationship between M. krauczuki and M. sanmartini. These results call for a reassessment of species relations within Melanophryniscus under an inclusive phylogenetic study.

Anadia pariaensis Rivas, La Marca, and Oliveros, 1999, and Anadia steyeri Nieden, 1914, are two particularly rare and poorly known lizards described from single specimens. In the case of A. pariaensis, it remains known from the holotype, whereas A. steyeri is known from three additional specimens reported in the literature after the original description of the species. A single new specimen of A. pariaensis and five of A. steyeri, including the first adult males recorded for both species, make possible a more representative description of both species, including descriptions of the hemipenes. Despite both species presenting some similar morphological characteristics, the examination of the hemipenial morphology revealed very different organs. The hemipenis of A. steyeri presents some characteristics that resemble the organs of two species from the Santa Marta Mountain Range in the “bitaeniata-group” (Anadia pulchella and Anadia altaserrania). On the other hand, the hemipenes of A. pariaensis are unique morphologically and cannot be associated with the hemipenes known from other species in the genus. We describe variation within both species, and we comment on possible sexual dimorphism (number and arrangement of the femoral pores), natural history, and the known geographic distribution of the species. We also comment on Anadia bumanguesa Rueda-Almonacid and Caicedo 2004 based on a new specimen, the second known. This species may be a synonym of A. steyeri.

Anadia pariaensis Rivas, La Marca, and Oliveros, 1999 y Anadia steyeri Nieden, 1914, son dos especies raras, escasamente conocidas y descritas con ejemplares únicos. En el caso de A. pariaensis, esta permanece conocida solo por el holotipo; mientras A. steyeri se conoce por cuatro ejemplares señalados en la literatura desde su descripción. En este trabajo, un nuevo ejemplar de A. pariaensis y cinco de A. steyeri, incluyendo los primeros machos adultos registrados para ambas especies hacen posible una descripción detallada, incluyendo la descripción de los hemipenes. A pesar que estas especies presentan algunas características morfológicas similares, el examen de la morfología hemipenial reveló órganos muy diferentes. El hemipene de A. steyeri, presenta algunas características que lo asemejan a los órganos de dos especies del grupo bitaeniata de la sierra de Santa Marta (Anadia pulchella y Anadia altaserrania). Por otra parte, el hemipene de A. pariaensis es único morfológicamente, y no puede ser actualmente asociado con los hemipenes conocidos para otras especies en el género. Se describe la variación intraespecífica, posible dimorfismo sexual (número y disposición de los poros femorales), historia natural y distribución geográfica conocida para ambas especies. Por último, se analiz

The diel and seasonal calling activities of anurans are regulated by several environmental factors. We studied the effect of environmental factors on patterns of calling behavior of six sympatric frogs in an area of Atlantic rain forest at Ilha Grande, south of Rio de Janeiro state, Brazil. The number of calling males and the number of calls of each species were recorded at hourly intervals from October 1998 to September 2000. Two analyses were performed: hourly calling behavior of males of each species was related to air temperature, and monthly calling was related to air temperature and cumulative short-term rainfall. Males of Leptodactylus marmoratus, Aplastodiscus eugenioi, Physalaemus signifer, Scinax hayii, and S. trapicheiroi called mainly at night, whereas male Ischnocnema parva called mostly at dusk and dawn. The species studied at Ilha Grande rain forest called mainly in the wettest and warmest months. Scinax trapicheiroi, P. signifier, and A. eugenioi called throughout the year. Leptodactylus marmoratus was the only species whose calling behavior was restricted to a few months. Air temperature had a significant effect on the hourly number of calls for L. marmoratus, A. eugenioi, S. hayii, and S. trapicheiroi, and rainfall had a significant effect on the monthly number of calls of I. parva.

Basic ecological information is lacking for most caecilian amphibian populations, especially those of the Neotropical region where only few and nonquantitative ecological data were obtained for a small number of species. The Neotropical genus Caecilia is the most diverse of Gymnophiona with 33 species, for which natural history information is restricted to the description of clutch size for just one species. We provide natural history data based on 61 specimens of Caecilia gracilis found in a riparian forest in Cerrado biome in northeastern Brazil. No sexual dimorphism was found in morphometric and meristic data analyzed, probably because of functional constraints related to subterranean life. No specimens were found in the dry season, but in the wet season they were found at soil depth ranging from 5 to 31.5 cm, suggesting that seasonal vertical migration in C. gracilis occurs. In terms of both frequency and number, earthworms were the most important prey items encountered, thus suggesting a specialized diet in C. gracilis. We found Trematoda and Nematoda parasites in low numbers and at low prevalence.

We quantified the effects of different auditory stimuli on the locomotor performance during the escape responses of two species of arboreal lizard, Anolis sagrei and Anolis carolinensis, with two different groups per each species, that were either long-term captives or recently caught. Other than the presence or absence of a loud sound, we used conventional methods for handling the lizards and eliciting an escape. For both species and times in captivity, the addition of a loud sound significantly increased the escape running speed, in part by decreasing the amount of pausing. Although the trends were similar for the recently caught individuals and the long-term captives, the magnitude of the effect of the loud sounds was less for the recently caught individuals. Anolis sagrei was faster than A. carolinensis regardless of the stimulus, and the rank order of individuals based on performance within each experimental group and species did not change significantly with different auditory stimuli. Our results suggest the auditory system may be important for detecting and evading threats despite the lack of vocalization in these lizards.

Two species of Ratsnake (Elaphe bairdi and Elaphe obsoleta) inhabit different environments in Texas but come into contact with one another on the southwestern edge of the Edwards Plateau. Morphological intergrades have been described by previous studies, yet no genetic evidence of hybridization has ever been reported. We tested for evidence of hybridization and population structure using geographic data, mitochondrial DNA, and microsatellite markers. Cytochrome-b fragments were analyzed for 23 E. bairdi and 33 Elaphe obsoleta lindheimeri from Texas using maximum parsimony and Bayesian-based approaches. All individuals were subjected to Bayesian assignment probability tests based on six microsatellite loci. Overall, sequence divergence was low within E. o. lindheimeri (0.1–0.5%), and higher within E. bairdi (0.1–2.16%). Significant structuring was recovered from mitochondrial haplotypes but not from microsatellite genotypes. Phenotypic intergrades exhibited intermediate or incongruent species assignments based on their nuclear and mitochondrial genomes, suggesting admixture. However, gene flow between E. bairdi and E. o. lindheimeri remains strictly constrained to the zone of sympatry, and these separate lineages remain intact and independently evolving.

Growth, age at maturity, and survival are life-history parameters that provide important information for understanding population dynamics. We modeled growth and age at maturity for an island population of Arboreal Salamanders, Aneides lugubris, using snout–vent length (SVL) growth intervals from a 4-yr capture–mark–recapture study fit to the von Bertalanffy growth interval model. We estimated annual survival as a function of SVL using a multistate open robust design model, and computed age-specific survival using results from the von Bertalanffy growth model. Arboreal Salamanders have indeterminate growth that slows with age from hatchling size (24.4-mm SVL) to the mean adult (asymptotic) size of 66.0-mm SVL. Age at maturity is 2.69 yr, and average adult age is 8–11 yr. Annual survival increased with age from 0.363 in age 0 to 0.783 in ages >4 yr. Our results provide the first estimates of life-history parameters for this species and indicate similarities to other terrestrial salamanders from low-elevation Mediterranean climates.

The intensification of modern agriculture may impact amphibian populations through habitat loss and the direct and indirect effects of the pesticides upon which it relies. The increased homogeneity of modern agricultural landscapes may be detrimental in times of extreme low and high temperatures associated with climate change, as refuge abundance and habitat connectivity decrease. In this study, we evaluated the impacts of the herbicide glyphosate and subsequent intense drought on the Common Tree Frog, Hypsiboas pulchellus, inhabiting an agricultural landscape. We examined a series of organismic indices (stomach content index, hepatosomatic index, body fat index, gonadosomatic index, condition factor) as well as biomarkers of oxidative stress (hepatic catalase activity and reduced glutathione [GSH] content), exposure to contaminants (hepatic gluthatione-S-transferase activity), and genotoxicity (frequency of micronuclei). No significant differences were observed in the parameters measured when comparing frogs sampled before, 2, and 15 days after glyphosate exposure. However, anurans sampled in the same site two months later, when a drought was at its peak, presented a decrease in stomach content and hepatosomatic index, as well as an increase in hepatic catalase activity, hepatic GSH content and micronuclei frequency in peripheral circulating erythrocytes. Our findings demonstrate that drought is challenging to these anurans in this environment as evidenced by an apparent reduction in food intake and oxidative stress.

Chemical signals may communicate information about discrete character states, such as species and sex, as well as continuously varying characteristics that affect mate assessment. Here, we investigate whether body size is assessed from chemical cues of Striped Plateau Lizards (Sceloporus virgatus). Preliminary evidence indicated that males may respond to female chemical cues in a size-dependent manner. Because larger females may be more fecund, we hypothesized that in choice tests, males would prefer chemical cues from larger females. We compared male response to pairs of chemical cues obtained from adult females that differed in body size by ∼12%. Males did not discriminate between cues based solely on relative body size of the donors, but male preference was correlated with the body size of the larger donor female, indicating that absolute body size also played an important role. The preference scores were positive (indicating a preference for the larger female) only when the pair of donor females was relatively large and were negative (indicating a preference for the smaller female) when the donor pair was relatively small. Thus, males had a stronger chemosensory response to cues from the largest “large” females and the smallest “small” females. Overall, male response was more complicated than expected; we did not find a consistent preference for the cue from the largest female, as was expected based on the selective advantage of mating with larger, more fecund females. We suggest that the chemical composition of the female cue may signal additional information such as reproductive state.

Terrestrial plant litter is an important subsidy to freshwater ecosystems, where it serves as a basal resource in benthic food webs. Litter quantity and decomposition rate strongly influence energy flow through these food webs. Litter quantity often increases following nonnative plant invasions, but the impact this additional litter has on aquatic consumers is largely unknown. We conducted an experiment in outdoor microcosms containing plant litter, microbes, algae, and tadpoles. Many tadpoles feed on biofilms (bacteria, fungi, and algae) that develop during decomposition; as such, they are ideal organisms to test bottom-up effects of litter subsidies. We used a related pair of native and nonnative wetland grasses to investigate whether litter quantity affects tadpole performance. Tadpole performance metrics (developmental stage, size, and survival) showed significant positive responses to increased litter quantity but were mostly unaffected by plant species. Therefore, litter quantity was the primary determinant of tadpole performance in our experimental community. We suggest that changes to litter quantity can have important impacts on larval amphibians.

Toe and tail clipping are commonly used methods for permanent marking of animals and for obtaining tissue samples for genetic analyses. Although it has been tested whether toe clipping affects locomotor performance (and thus potentially the fitness of an individual), little is known about the effect of tail clipping. Tails are important organs in many amphibians and reptiles and are used for balance or stability during locomotion or as prehensile organs. Effects of tail autotomy or the removal of large parts of the tail have previously been demonstrated. Here, we test whether the removal of a small part (<5 mm) of the distal tail in chameleons affects their ability to cling to branches of different diameters by measuring gripping strength using of a force platform. Our data show no significant or directional effect of tail clipping on the maximal forces that can be generated by the tail and, thus, suggest that tail clipping can be used as a method for tissue collection.

Determining how animals respond to habitat loss and fragmentation requires detailed studies of habitat use and behavior in regions that vary in their degree of fragmentation. As predators, snakes are an important component of ecosystems, yet little is known about how they respond behaviorally to habitat loss. Using radiotelemetry at two locations that differ in their habitat patch size, we examined habitat-use patterns at two spatial scales and movement patterns for the endangered Eastern Foxsnake (Phantherophis gloydi). Movement patterns were similar at the two locations, but individuals exhibited greater variation in home-range size, and males and gravid females dispersed further from hibernation sites within the larger natural habitat patch. Individuals from both locations preferred marsh at the home-range scale, but open dry habitat at the location scale. Within the smaller habitat patch, however, these preferences were accentuated with snakes avoiding agricultural fields. At the landscape scale, individual occurrence records were found closer to, and in areas with a higher density of, usable habitat than locations that are distributed randomly.

A recent study of Ratsnakes (Elaphe obsoleta) in Texas found that adult mortality was higher for females than males, consistent with the cost of reproduction in snakes being higher for females. To determine whether the same pattern prevailed in a northern population of Ratsnakes, we used data collected using radio-telemetry to test several predictions of the cost-of-reproduction hypothesis. Contrary to there being a cost to reproduction, mortality rates did not differ between juvenile and adult snakes and, contrary to females having a higher cost of reproduction, mortality rates among adults did not differ between males and females. The only evidence consistent with reproduction increasing mortality risk was higher winter mortality for females in poor condition following egg laying. Mortality did not vary with activity but increased with time spent basking, although group differences in basking were not sufficient to produce differences in mortality. High risk of winter mortality in this population may require all Ratsnakes to behave in ways that mask mortality costs associated with reproduction. To determine whether our results for Ratsnakes in Ontario are anomalous or reflect something more substantial about the cost of reproduction in snakes, details of mortality patterns from more species, ideally with diverse ecologies, are needed.

A fragmentary fossil lizard from Uquía Formation (Late Pliocene), Jujuy Province, Argentina, is described. The material consists of disarticulated cranial bones from the snout and jaw that were part of a microvertebrate fossil assemblage generated by accumulation of predatory birds pellets. The phylogenetic analysis of 396 morphological characters indicates a sister-group relationship between the new taxon and a clade formed by the families Liolaemidae, Leiocephalidae, and Tropiduridae. Its uncertain position and substantial morphological differences justify its placement in a new genus. We present a detailed osteological description of the material, and compare the morphological features with other Iguanoidea. In the context of this new analysis of Iguania, we included Pristiguana brasiliensis, the oldest know iguanian from South America. The results of this analysis support the monophyletic status of Iguanoidea and other groups within Iguania that are named and diagnosed.

Describimos restos fragmentarios de un lagarto fósil procedente de la Formación Uquía (Plioceno Tardío) en la Provincia de Jujuy, Argentina. El material consiste de huesos craneales desarticulados del hocico y la mandíbula que fueron recuperados de un ensamble fósil de microvertebrados, el cual es una acumulación de egagrópilas generado por la actividad trófica de aves depredadoras. El análisis filogenético de 396 caracteres morfológicos indica que el nuevo taxón es el grupo hermano de un clado formado por las familias Liolaemidae, Leiocephalidae y Tropiduridae. La posición dudosa de este fósil y las substanciales diferencias morfológicas justifican clasificarlo como un género nuevo. Incluimos una descripción morfológica detallada del material fósil y comparamos su anatomía con otros miembros de Iguanoidea. En el contexto de este nuevo análisis de Iguania, incluimos a Pristiguana brasiliensis, el cual hasta hoy es el iguanio más viejo que se conoce de América del Sur. Los resultados de este análisis filogenético apoyan el estatus monofilético de Iguanoidea y de otros grupos dentro de Iguania, los cuales se definen y diagnostican.

Almost nothing is known about the biology of the recently described, enigmatic Lao Newt (Laotriton laoensis). Using a combination of field surveys and village interviews, we determined that its geographic range is restricted to a small area in northern Laos. Aquatic adults occur in pools of small, cold, slightly acidic, flowing streams that traverse a variety of vegetation types at elevations above 1,100 m. Mark–recapture estimated that aquatic adults are locally abundant where they occur. Analysis of stomach contents found that the species consumes a wide variety of invertebrates and vertebrates, including large prey, and females eat conspecific eggs. Aquatic courtship takes place during the coldest and driest part of the year, and eggs are laid over a long period between dead leaves that accumulate on the bottom of stream pools. Larvae are aquatic and metamorphose into terrestrial efts. The species is threatened from overharvesting for food, medicine, and especially the international pet trade.

A new species of squeaker frog (Arthroleptis) is described from Ngozi Crater in the Poroto Mountains of southwestern Tanzania. The holotype, and only specimen, was collected 80 years ago but remained undescribed because of past taxonomic confusion relating to large-bodied species of Arthroleptis from eastern Africa. Morphological study, including multivariate analysis of measurement data, indicates that this new species is distinguishable from other species of Arthroleptis, including large-bodied species such as Arthroleptis adolfifriederici, Arthroleptis affinis, Arthroleptis nikeae, Arthroleptis nguruensis, and Arthroleptis tanneri. The new species differs from other described species of Arthroleptis by the combination of its large body size, relatively long toes, and relatively small tympanum. The description of this new species further highlights the biological diversity of the Southern Rift Mountains.

Functional nephrons of the kidney with secondary sexual function are rare in vertebrates and descriptions of these structures do not unequivocally conclude that they aid in reproduction. This statement holds true for the collecting ducts of the pelvic kidneys in male salamanders, which appear to synthesize abundant secretory material during times of reproductive activity. To indirectly test the hypothesis that collecting ducts of the pelvic kidneys in salamanders are indeed secondary sexual structures, we investigated the correlation of collecting duct secretory activity with that of the seasonal secretory and growth cycles of three known secondary sexual structures: genial glands, dorsal glands of the cloaca, and tail. Male Red-spotted Newts (Notophthalmus viridescens) were captured every month and their urogenital organs were processed for general histological examination. To quantify the seasonal activity of the pelvic kidney collecting ducts, we measured the epithelial height of the collecting ducts, by month, and compared these data with the epithelial heights of the genial glands and dorsal glands and tail depth. The data indicate that there is a significant correlation between the seasonal secretory activity of the collecting duct epithelium and the seasonal activity of previously identified secondary sexual structures. Previously identified secondary sexual structures increase in epithelial height and tail height during the fall, winter, and spring and the collecting duct epithelium mirrors these increases directly. The strength of this correlation provides novel evidence that the salamander kidney collecting ducts may function as secondary sexual structures. However, the actual function of the secretions remains unknown.