Pedioplanis burchelli is a small oviparous lacertid lizard that inhabits rocky montane areas in the highveld grassland biome of South Africa. We studied its reproductive cycle by monthly monitoring of gravimetric, morphometric, and histological changes of the reproductive system of males and females throughout 1999. Reproduction took place in spring/summer, and gonadal activity of males and females was well synchronized and prenuptial. Photoperiod was the best predictor of seasonal fluctuations in testes mass and rainfall in the case of ovarian seasonality. Neither vitellogenic follicle count nor oviducal egg count were correlated with snout–vent length. Sexual size dimorphism with respect to certain body parts is explained either in terms of sexual selection, differential growth, or intraspecific food niche segregation. The absence of a significant difference in incidence in damaged tails between males and females may be indicative of similar levels of predation pressure.

A new species of Physalaemus belonging to the Physalaemus cuvieri species group is described from southern Bahia, Brazil. It inhabits the borders of Atlantic Rain Forest fragments, natural forest clearings, and cacao plantations. The new species is characterized by its medium size, robust body, warty skin, presence of inguinal glands, one pair of dorsal tubercles on the sacral region, and an interorbital black transversal stripe generally covering a pair of tubercles.

We review the taxonomic status of populations of toads referred to Bufo melanochlorus Cope, 1877, that occur in the wet forests on both Atlantic and Pacific versants of Costa Rica. Populations from Pacific versant of Costa Rica and adjacent Panama are qualitatively diagnosable from all other populations and are described herein as a new species. The taxon B. melanochlorus is restricted to populations in the Atlantic and Montane Slopes and Cordillera Central faunal areas of Costa Rica.

Call surveys are used widely to assess distribution and abundance of anurans. The durations of these surveys often are based on convenience rather than on empirical analysis. Knowing how frog detection varies with survey duration is valuable for designing sampling schemes, yet few studies have examined the relationship between survey duration and detection efficiency. We conducted call surveys for frogs in central Texas to assess effects of survey duration on detection efficiency. We controlled analytically for temporal and environmental covariates that had the potential to confound our assessment of survey duration. Cumulative detection efficiency of all species was 94% for 15-min surveys and did not increase appreciably with longer durations up to 30 min. Detection efficiency for number of species was significantly higher for 15-min surveys than it was for 5-min surveys, and the variability of detection efficiency decreased with increasing survey duration. Detection efficiency for number of calling individuals of Acris crepitans and Rana sphenocephala did not differ among 5-, 10-, and 15-min surveys. Of the temporal and environmental covariates examined, only the year in which a survey was conducted was significantly associated with detection efficiency for number of species. None of the covariates was significantly related to detection efficiency for A. crepitans or R. sphenocephala. When sampling resources such as time and personnel are limited, knowledge about detection efficiencies is essential for allocating survey effort.

The nomenclatural status of the synonyms of Hyla pardalis Spix, 1824, is reevaluated, the synonymy of Hyla (Lophopus) corticalis Burmeister, 1856, is supported, and Hyla rubropunctata Lutz, 1973 (nomen nudum), is synonymized with H. pardalis. Hyla lundii Burmeister, 1856, previously in the synonymy of H. pardalis, is revalidated. Hyla pustulosa Reinhardt and Lütken, 1862, and Hyllela punctatissima Reinhardt and Lütken, 1862, previously synonyms of H. pardalis, are transferred to the synonymy of H. lundii. Hyla biobeba Bokermann and Sazima, 1974, is synonymized with H. lundii. Diagnoses and comparisons with the members of the Hyla boans species group are provided for H. pardalis and H. lundii, and their geographical distributions are described. The type locality of H. pardalis is discussed and reallocated.

A central issue in comparative biology is identifying the relative importance of historical (phylogenetic) versus present-day (ecological) factors in shaping phenotypic traits of organisms. Herein, we investigate effects of sex, ontogeny, and season on diet of Epipedobates flavopictus, a species restricted to open landscapes in central Brazil. Based on prey frequency, number, and volume, the most important prey categories were ants, termites, beetles, spiders, and orthopterans. Prey number and volume increased significantly with snout–vent length (SVL), and the consumption of termites also increased with SVL. There were few effects of sex and season upon diet composition, average prey number, or average prey volume, all independent of SVL. Reproductive females consumed larger prey, in great numbers, likely to increase energy uptake. As is true for most congeners, as well as species of closely related genera, ants are an important component in the diet of E. flavopictus. However, in contrast to its forest relatives, E. flavopictus consumes large amounts of termites, revealing the influence of prevailing ecological conditions. The small volume of ants in the diet of E. flavopictus and the high toxicity of its skin are not in agreement with the hypothesis of a causal relationship between skin toxicity and ant consumption.

We report on the influence of observer presence and handling on activity patterns (stride frequency) of the Australian sleepy lizard (Tiliqua rugosa). Over a 17–week period, we maintained continuous records of activity of 10 adult lizards using lightweight activity loggers recording lizard body temperature and stride frequency every two minutes. At all times of day and throughout the season, we recorded the effect of three levels of observer disturbance (observed only, briefly handled [< 60 sec], and held for an extended period [30–45 min]), on lizards either inactive or active at the time of interaction. Following all disturbance types, there was an increase in average stride frequency that lasted for up to an hour. This is a significant period for an animal that is generally active for only a few hours in the day. The extent of this effect was higher for active than for inactive lizards, when observed or briefly handled, and increased with the level and duration of the disturbance. Both inactive and active lizards when held for an extended period responded with a very high average level of activity. We found that shifts to behavior following brief handling (e.g., attaching a cotton spool) can be minimized or prevented by working with inactive lizards early in the morning, when ambient temperatures (and hence lizard body temperatures) are relatively low. Protocol design for field-based behavioral studies involving lizards must avoid, or if necessary compensate, for biases that result from the effect of different levels of observer disturbance on activity patterns.

Early age classes of the Desert Tortoise (Gopherus agassizii) are particularly vulnerable to predation by several mammal and bird species. We studied tortoise survival at the Sand Hill Training Area of the Marine Corps Air Ground Combat Center, Twentynine Palms, California, from 1998 to 1999. We radiographed and thread-spooled 25 females to determine reproductive and nesting ecology. Predators consumed 11 of 42 monitored nests during the first 70 days of incubation. Ninety-one of 132 eggs in nests fenced after 70 days developed into healthy neonates. We recorded 0.84 and 0.91 neonate survival probability during dispersal in 1998 and 1999, respectively. Applying neonatal survival to egg success, we predict that 40% of individuals survived from oviposition to hibernation. Our findings support other chelonian life-history models indicating relatively high mortality early in life. Our data also suggest that neonatal Desert Tortoises are less susceptible to predation than was previously thought, perhaps because of their cryptic coloration and secretive habits. The Common Raven (Corvus corax) was not found to be a source of neonate mortality during this study.

Microhabitat use beneath the canopy of perennial woody plants by the heliothermic sleepy lizard (Tiliqua rugosa) was examined at a site near Mt. Mary in South Australia by testing whether the position adopted by lizards under bushes was influenced by their state of activity, time of day, or month. Thirty radio-tagged lizards were followed in 2000 during their spring period of activity (September–November). Lizard position beneath a plant canopy (one of nine sectors) and behavior were recorded for each observation (radio-tagged or random encounter). Active and inactive lizards showed nonrandom use of sectors beneath plant canopies: using mainly the center and north, northeast, and east sectors (northeast quadrant), but this changed with season. Temperature changes beneath plant canopies were measured, these resulted from diurnal and seasonal shifts in the sun's position. Temperature gradients in the north-south and east-west axes of bush canopies were shown to shift with time of day and season. Sector use by lizards reflected changing thermal conditions beneath plant canopies. When ambient conditions were cooler, lizards used the warmest northeast quadrant in the morning and the northwest quadrant in the afternoon. During hotter periods of the year lizards were found most often in plant centers. Proportion of records in the center and the southwest increased from September to November, whereas those in the north and northeast decreased over that period. Microhabitat use changed with lizard activity. Active lizards were found less often than inactive lizards in the center of bushes. Inactive lizards tended to avoid southern and western facing sectors. We suggest that, during the extended daily periods of inactivity, sleepy lizards are either selecting a position that has preferred microclimatic conditions within temperature gradients of canopies, or they may have evolved a preference for north and east facing sectors because of a consistent thermal advantage over the course of the changing daily thermal regime in a heat stressed environment.

A small skink of the genus Leptosiaphos from the Adamaoua Massif in Central-Northern Province of Cameroon is described. The new species is most similar to the East African Leptosiaphos kilimensis from which it differs in coloration and in having 22 scales around midbody.

Research on amphibian movement patterns can aid in strengthening amphibian conservation strategies. Yet for many species, there remain substantial gaps in our knowledge of such movement patterns. From 1999–2002, we documented movement patterns to and from breeding pools of both adult and juvenile Rana sylvatica LeConte (Wood Frog) and Ambystoma maculatum Shaw (Spotted Salamander) by using drift fence arrays at three restored vernal pools in Maine to lend insight into conservation strategies for these two species. Adults and juveniles of both species exhibited nonrandom movement at breeding pools directed preferentially from and toward closed-canopy forested habitat. Marked male, female, and juvenile R. sylvatica were recaptured at 30 m, 150 m, and 300 m from the pool in the surrounding terrestrial environment. Most terrestrial recaptures occurred within the forested wetland habitat to the north of the pool. Median snout–vent lengths (SVL) of recaptured juvenile R. sylvatica were progressively larger at greater distances from the pool. Number of juveniles emerging from the pool was positively correlated with number of juveniles recaptured two days later at 30 m, four days later at 150 m, and six days later at 300 m. Male R. sylvatica were 98% faithful to their breeding pools from 2001–2002, whereas female R. sylvatica were 88% faithful. Male and female A. maculatum were 100% faithful to their breeding pools during the same period. Both species' (adult and juvenile) nonrandom movement toward forest upon leaving breeding pools suggests that quality of adjacent terrestrial habitat is relevant to both juvenile and adult pool-breeding amphibians. High levels of pool fidelity observed in these two species emphasize the importance of conserving vernal pools and mitigating for pool-losses on-site if the nonbreeding habitat is still available. Correlations between amphibian migrations and weather variables varied between years and species, suggesting emigration, immigration, and dispersal may be associated other environmental variables in conjunction with temperature and precipitation. However, heightened activity of both species (adults and juveniles) in response to temperature and precipitation can inform the timing of monitoring efforts and conservation strategies aimed at protecting migration routes.

Alteration and loss of habitat is a major factor in the recent declines of many turtle populations. However, there are few studies of turtle populations in areas that are used intensively by humans. We used temporal symmetry modeling and an information-theoretic approach to model selection to estimate survival and recruitment in a population of Ornate Box Turtles, Terrapene ornata, in fragmented, isolated habitat over an eight-year period. Apparent annual survival was high during this period (0.97, SE = 0.06), as was the seniority probability (0.95 ± 0.04). Recruitment into the adult population (λ) was estimated at 1.02 (± 0.06). Our results suggest a healthy population, but we note several reasons for a cautious management approach. These include a vulnerability of λ to the removal of adults, the need for increased recruitment to offset loss of genetic diversity, and the uncertainty of our estimates resulting from the sampling and modeling processes.

Eastern Spadefoot Toads (Scaphiopus holbrookii) require fish-free, isolated, ephemeral ponds for breeding but otherwise inhabit surrounding uplands, commonly xeric longleaf pine (Pinus palustris) and wiregrass (Aristida beyrichiana) ecosystem. Fire suppression in the Florida sandhills has the potential to alter upland and pond suitability through increased hardwood densities and resultant higher transpiration. In this paper, we explore breeding and metamorphic emigration movements in relation to weather, hydrological conditions of ponds, and surrounding upland matrices. We use nine years of data from continuous monitoring with drift fences and pitfall traps at eight ephemeral ponds in two upland matrices: regularly burned, savanna-like sandhills (N = 4), and hardwood-invaded sandhills (N = 4). Neither adult nor metamorph captures differed between ponds within the two upland matrices, suggesting that they are tolerant of upland heterogeneity created by fire frequency. Explosive breeding occurred during nine periods and in all seasons; adults were captured rarely otherwise. At the landscape-level, an interaction between rainfall and maximum change in barometric pressure were the top significant predictors of explosive breeding. At the pond-level, rainfall and the change in pond depth during the month prior to breeding were the top significant predictors of adult captures. Metamorphic emigrations occurred following transformation and usually were complete within a week regardless of rainfall levels. Movement by adults and metamorphs was directional, but mean directions of adult emigrations and immigrations did not always correspond. Our results suggest that spadefoot toads are highly adapted to breeding conditions and upland habitat heterogeneity created by weather patterns and fire frequency in Florida sandhills.

Introduced, nonnative brook trout (Salvelinus fontinalis) were removed from a mountain lake in Mount Rainier National Park, Washington, to examine the capacity of native Ambystoma gracile (Northwestern Salamander) in the lake to respond to the intentional removal of fish. Temporal trends (Δ̄N) were calculated for A. gracile larvae/neotene and egg mass relative abundances in the Fish Removal and an adjacent Fishless Lake. The diel and spatial patterns of A. gracile in the lakes were also enumerated during time-intervals of fish presence in and after fish removal from the Fish Removal Lake. Sixty-six fish were removed from the Fish Removal Lake. The Δ̄Ns for relative abundances in the Fish Removal Lake were positive for the study period and indicated that the number of larvae/neotenes and egg masses observed in the lake increased concurrent with the removal and extirpation of fish from the lake. Numbers of larvae/neotenes and egg masses observed in the Fishless Lake varied annually, but no overall positive or negative trends were evident during the study. Ambystoma gracile in the Fish Removal Lake, during fish presence, were predominantly nocturnal and located in the shallow, structurally complex nearshore area of the lake. After fish were removed, the number of A. gracile observed in the lake increased, especially during the day and in the deeper, less structurally complex offshore area of the lake. Fishless Lake A. gracile were readily observed day and night in all areas of the lake throughout the study. The A. gracile in the Fish Removal Lake behaviorally adapted to the presence of introduced fish and were able to recover from the affects of the fish following fish removal. This study underscores the important relationship between species life history and the variability of responses of montane aquatic-breeding amphibians to fish introductions in mountain lakes.

Cnemidophorus abaetensis and Cnemidophorus ocellifer occur in sympatry in Bahia State, Brazil. We evaluated the extent to which these species differed in their activity, active body temperature, and in their relationship with the thermal environment. During March to May of 2000, mean body temperature during activity of C. abaetensis was 36.7 ± 1.7°C (± SD), while that of C. ocellifer was 36.5 ± 1.8°C. The activity cycle of the two species was different, although activity peaked for both species in the morning. This may be because of structural differences in the vegetation of the microhabitats used by the two species. Cnemidophorus abaetensis used more shaded environments than C. ocellifer, and this difference in exposure may have allowed longer activity. Segregation in spatial resource use between these two Cnemidophorus may facilitate coexistence of such closely related species.

At its southwestern range limit in southeastern Arizona, the Desert Box Turtle Terrapene ornata luteola, takes refuge in subterranean mammal burrows, primarily those of the Kangaroo Rat Dipodomys spectabilis, from November through June. I inferred temporal and physiological characteristics of turtles in burrows from temperatures collected with miniature data loggers buried in the soil and attached to turtles from August 2001 through June 2003. In the fall, entrance into hibernation varied among individual turtles and between years from 18 October to 6 December. Mean daily body temperatures at the beginning of hibernation were about 14–18°C. From December through February, body temperatures averaged about 9°C and were slightly less than and highly correlated with the 30-cm soil temperature. By April, body temperatures of turtles approached levels exhibited by surface-active turtles (minimum approximately 18°C for moving turtles) but turtles did not emerge from burrows until the summer monsoons began about three months later. Thus, the five-month hibernation period of T. o. luteola was contiguous with a three-month estivation period for a total annual period of subterranean refuge of about eight months. Except for extending into warm months, the annual inactive period of T. o. luteola in southeastern Arizona was not remarkably different from that in other parts of the species' range.

Tadpoles of Tomopterna breviceps from five different sibships were subjected to pure (siblings) or mixed (kin and nonkin) rearing conditions at varying densities to determine relative influence of kinship and density on metamorphic traits of larval growth, larval period, and size at metamorphosis. Individual rearing of 50 tadpoles from five different parental lines revealed no significant difference in any metamorphic traits among sibships. At a given density, metamorphic traits were comparable between sibling and mixed groups indicating an absence of kinship influence. However, progressive increase in the number of tadpoles (density) affected severely the metamorphic traits regardless of the kinship/mixed rearing conditions. This resulted in an increase in larval period, decrease in the size of metamorphs in comparison to those reared at a lower density or uncrowded conditions. Our study shows that in T. breviceps density of rearing rather than kinship plays a major role in affecting the metamorphic traits.

I describe the tadpole of Colostethus kingsburyi (Boulenger, 1918), a dendrobatid frog that occurs in Ecuadorian Amazonia at the foothills of the Andes. The tadpole of C. kingsburyi is similar to other dendrobatid tadpoles with respect to body shape, labial tooth row formula, arrangement of papillae of the oral disc, jaw serrations, and location of the spiracle and vent tube. It differs in the number of papillae on the oral disc and by having the terminus of the tail heavily blotched. The number of marginal papillae around the oral disc in tadpoles of C. kingsburyi varies ontogenically; this type of ontogenetic variation has been documented only in a few Colostethus tadpoles and may be more widespread than previously recognized. Phenetic resemblance of C. kingsburyi and tadpoles of Allobates femoralis is remarkable and supports a current hypothesis of a close phylogenetic relationship between these taxa. The identification of larval synapomorphies requires analysis of a larger dataset.

In a rocky outcrop in the municipality of Diamantina, Minas Gerais State, Brazil, two species of Tropidurus (Tropidurus hispidus and Tropidurus montanus) are found syntopically. We studied their ecology and resource use by assessing their food habits, thermal biology, microhabitat use, and time of activity. Lizards of both species were active throughout the day and were recorded predominantly on rocky surfaces. Lizards of both species ate mainly arthropods but also consumed some plant material. Tropidurus hispidus ate a greater proportion of plant material (mainly flowers) than T. montanus, whose diet was dominated by ants. We conclude that both T. montanus and T. hispidus have considerable overlap in resource use.

Studies of prey responses to different predators are needed to investigate costs and benefits of particular antipredator responses and to unravel community-level effects on phenotypic plasticity. We reared laboratory-bred larvae of Arizona Tiger Salamanders, Ambystoma tigrinum nebulosum with either of two common predators, diving beetle larvae (Dytiscus sp.) or dragonfly naiads (Anax junius). Relative to controls, salamander larvae in both predator treatments had shorter snout–vent lengths and deeper tails; these differences may be related to increased swimming ability. In addition, larvae reared with dragonfly naiads had shorter tails than those reared with diving beetle larvae, possibly in response to different predator foraging strategies or differences in strength of selection imposed by each. Salamander larvae from predator treatments weighed less than controls, with salamanders reared with dragonflies weighing the least. This suggests that salamanders respond more strongly to dragonfly naiads than diving beetles and that dragonflies may be a more important predator. Thus, salamander larvae may distinguish between different predators, highlighting the utility of studying effects of multiple predators on phenotypic plasticity of prey.

How individuals are located in space can impact their interactions. We investigated spacing behavior of tadpoles of Gray Treefrogs (Hyla versicolor) and Green Frogs (Rana clamitans) at two densities in the laboratory. Tadpoles of H. versicolor were more dispersed than those of R. clamitans. Spacing (e.g., random, dispersed, or aggregated) of tadpoles was not affected by density; however, dispersion tended to increase during the experiment. Our results suggest that spacing behavior in tadpoles is dynamic over time and may provide some insight into the outcome of intra- and interspecific interactions.

We used night driving to examine large scale habitat associations of four common desert anurans in Big Bend National Park, Texas. We examined association of soil types and vegetation communities with abundance of Couch's Spadefoots (Scaphiopus couchii), Red-spotted Toads (Bufo punctatus), Texas Toads (Bufo speciosus), and Western Green Toads (Bufo debilis). All four species were disproportionately associated with frequently inundated soils that are relatively high in clay content. Bufo punctatus was associated with rocky soil types more frequently than the other three species. Association between all four species and vegetation types was disproportionate in relation to availability. Bufo debilis and Bufo punctatus were associated with creosote and mixed scrub vegetation. Bufo speciosus and Scaphiopus couchii were associated with mesquite scrub vegetation. Bufo debilis, Scaphiopus couchii, and B. speciosus were more tightly associated with specific habitat types, whereas B. punctatus exhibited a broader distribution across the habitat categories. Examining associations between large-scale habitat categories and species abundance is an important first step in understanding factors that influence species distributions and presence-absence across the landscape.