Although broad habitat preferences are known for many species of conservation concern, identification of key microhabitat elements critical to persistence and reproduction is a crucial and generally understudied aspect in conservation. In this study, we examined diurnal microsite selection in the five-lined skink (Eumeces fasciatus) to identify important microhabitat elements in its most northerly populations. Seven populations distributed across the southern edge of the Canadian Shield were sampled. To determine which microhabitat elements are important in diurnal microsite selection, ten microhabitat features were compared in occupied and unoccupied quadrats. A Classification and Regression Tree analysis showed that the best predictor of E. fasciatus presence in a meter-by-meter quadrat was proportion of cover rock. This finding will help in modeling or identifying potential historical, current or future habitat in these most northern E. fasciatus populations, and aid population managers in monitoring the habitat suitability of extant five-lined skink populations.

We analyzed trophic ecology and its relationship with environmental variables for two leptodactylid species, Leptodactylus latinasus and L. bufonius (Anura: Leptodactylidae). The two species are common around Corrientes City, Argentina, where they live in the same habitat. The main objectives were to analyze the diets and patterns of coexistence relative to the microhabitat of each species. Weekly sampling was carried out January 1997–February 2000. A randomization test and canonical correspondence analysis (CCA) were used for data analysis. In L. latinasus, the diet was dominated numerically by isopterans and coleopterans (25.25% and 21.21%, respectively) and volumetrically by insect larvae (37.14%). In L. bufonius, the alimentary contents were dominated numerically by isopterans (60.49%) and volumetrically by coleopterans (62.47%). The trophic niche breadth was wider in L. latinasus (6.55) than L. bufonius (2.44). The overlap in the trophic niche (prey proportion) was higher (O_jk = 0.81) and significantly greater than the expected mean value obtained by chance (0.27). Spatial niche overlap between the two species was low (O_jk = 0.331) and not significantly different than the mean value expected by chance (0.52). Differences in microhabitat use were observed. While L. latinasus showed strong preference for mud, ground with crevices, and short grass and mud, L. bufonius showed preferences for dry land and short grass. In addition, the presence of this species was positively correlated with temperature and rainfall variables. Niche complementarity was observed between these species; although they exhibit high overlap in food, they tended to have low overlap in microhabitat use.

For six breeding seasons (1997–2002), we conducted an intensive mark-recapture study on a breeding population of the spotted salamander, Ambystoma maculatum, near the southern edge of their range in east-central Alabama. A drift fence completely encircling an ephemeral pond was used to capture all adult salamanders migrating into or out of the pond, and passive integrated transponders were used to provide individual identification. The Jolly-Seber method of population estimation was used to estimate three population parameters (size, gains, and survivorship); population growth rate was also estimated. Gains varied annually, ranging from 24 ± 16 to 101 ± 24, and population growth rate was low (r = 0.18 ± 0.188), suggesting inconsistent recruitment. Consistent with life history parameters of long-lived, late-maturing species, survivorship (range 0.629 ± 0.064 to 0.699 ± 0.08) and breeding population sizes (range 189 ± 24 to 260 ± 16) remained essentially constant. The demographics for A. maculatum provided by this study are useful for planning conservation initiatives.

Barking frogs (Eleutherodactylus augusti) are distributed from southern Mexico along the Sierra Madre Occidental into Arizona and the Sierra Madre Oriental into Texas and New Mexico. Barking frogs in Arizona and most of Texas live in rocky areas in oak woodland, while those in New Mexico and far western Texas live in rodent burrows in desertscrub. Barking frogs in each of the three states have distinct coloration and differ in sexually dimorphic characters, female vocalization, and skin toxicity. We analyzed advertisement call variation and conducted a phylogenetic analysis using mitochondrial DNA sequences (ND2 and tRNA regions) for barking frogs from these three states. Advertisement calls of frogs from Arizona were significantly longer in duration, higher in frequency, and had longer duration pulses than those of frogs from either New Mexico or Texas; frogs from these latter two sites were indistinguishable in these call variables. Phylogenetic analysis showed deep divisions among barking frogs from the three states. Differences in call structure, coloration, and mitochondrial DNA sequences strongly suggest that barking frogs in Arizona are reproductively isolated from those in New Mexico and Texas. Our results indicate that either northern populations are connected via gene flow through southern Mexico (i.e., they are subspecies as currently recognized), or represent independent lineages as originally described (i.e., western barking frogs, E. cactorum in AZ, and the eastern barking frogs, E. latrans in NM, TX).

Optimal escape theory predicts that prey permit closer approach by predators when fleeing is more costly, but does not predict other aspects of escape such as distance fled or the likelihood of returning to the initial site in the presence or absence of a resource such as food. Because a lizard preparing to feed may lose the feeding opportunity, optimal escape theory predicts that the lizard should allow a predator to approach closer before fleeing when a stationary food source is present than in its absence. In addition, we predicted that when a predator was nearby, lizards would flee a shorter distance and return more often when food was present than absent. We presented adult males of the omnivorous Balearic lizard, Podarcis lilfordi, with a tethered piece of pear or a pebble of similar size and shape. One of us approached a lizard in a standardized manner, stopping and remaining still when the lizard fled. The other investigator recorded escape and return behaviors. Lizards in the presence of food permitted closer approach before fleeing, fled a substantially shorter distance, and were far more likely to return to the site of stimulus presentation than when a pebble was presented. These findings suggest that prey may alter several aspects of escape behavior to reduce costs due to lost opportunities, and present a likelihood that interspecific variation exists in the combination of aspects of antipredatory behavior that are modified.

We measured temperature variation in a free-ranging ectotherm by attaching micro-dataloggers to the carapaces of 34 painted turtles (Chrysemys picta) in a farm pond located in Davidson, NC. Water and mud temperatures (T_w) were simultaneously monitored. We successfully recorded external shell temperature (T_s) in 18 turtles from September 2001–April 2002 and 23 turtles from April 2002–October 2002. Turtle temperatures steadily decreased through the fall and basking continued until the middle of December. Minimum yearly T_s (1–3 C) occurred during the same week (2–7 January 2002) for all turtles. Turtle temperatures then steadily rose and basking resumed in February. More basking events took place during February and March than during other months of the year when C. picta used basking to reach T_s 5–16 C above the maximum water temperature. During the summer, turtle T_s reached values similar to those achieved via basking during cooler months, apparently without leaving the water. The number of basking events per month was significantly different between consecutive months for seven of eleven consecutive month pairs. Contrary to our predictions, more basking events were recorded for male turtles than for females overall for the year. Monthly basking profiles were also significantly different for male and female turtles, with males basking earlier in spring than females. Mean maximum weekly T_s were significantly higher for males than for females. Our research documents seasonal variation in temperature and basking behavior in C. picta, as well as the importance of basking for achieving high temperatures during cooler months. We demonstrate the effectiveness of microdatalogger technology for measuring temperature variation in small reptiles and we contribute to a more complete understanding of the thermal biology of C. picta.

Female-specific reproductive coloration is widespread among lizards, prompting several hypotheses to explain the possible function(s) of such coloration in females. I tested four of these hypotheses using observational and experimental field studies of free-ranging collared lizard females, Crotaphytus collaris, which develop orange markings on the lateral torso in association with the reproductive cycle. Orange markings did not appear to function for advertisement to female competitors because females rarely displayed their coloration during interactions with consexual competitors, and markings developed well before the occurrence of peak aggression among females. By contrast, females frequently displayed their lateral torso when courted by males. The number of displays given to courting males did not differ in females that had and those that had not yet developed orange markings, suggesting that female coloration does not function for sexual recognition in collared lizards. Females developed orange pigmentation while they matured their first clutches, and markings were maintained between and throughout the production and oviposition of the second and third clutches. Male courtship encounters with females having naturally developed markings were longer and involved more male displays than those with females that had not yet developed their coloration, suggesting that development of coloration by females functions to stimulate male courtship when females are receptive. To test this hypothesis, I established nine female pairs of size- and age-matched females that had early vitellogenic eggs, but had not yet developed reproductive pigmentation. Female pairs were each residents on the territories of nine different males. One female in each pair was painted with orange spots and bars to mimic the natural orange coloration and the other with light brown to match the natural background coloration of female C. collaris and mask naturally developed pigments. Males began courting orange-painted females within 2 h, and, on average, orange females were courted over five times more frequently than brown females. The difference in courtship frequency did not appear to result from males avoiding brown females because the average distance between males and females in the two treatment groups was similar. These results support the hypothesis that reproductive coloration in C. collaris females stimulates courtship rather than signaling rejection of courtship to males.

Many techniques commonly used by herpetologists for monitoring amphibian populations and communities yield censuses of the total adult population size (N). However, for many studies, e.g., of reproductive output, development of populations and potential for evolutionary changes, the effective population size (N_e) must be known. While modern molecular techniques make it possible to measure N_e, they are expensive, work-intensive and may not be possible or necessary for many questions on amphibian reproduction. For females of two species of water frog (Rana lessonae and R. esculenta), we investigate the effectiveness of several techniques to determine the presence or absence of eggs. The direct methods are (1) dissection of dead frogs and (2) a small skin incision into the abdominal side of live females. The indirect methods, all applied to live frogs, include (3) visual inspection of body shape, (4) tactile inspection of the epidermis, (5) transillumination with a strong cold light source, (6) ultrasound, (7) electromagnetic measurement of total body electrical conductivity (TOBEC), (8) calculation of body condition index and (9) analysis of blood plasma testosterone titers. Only two indirect methods were somewhat successful at predicting whether females were gravid. Testosterone titers (9) yielded the best results (ca. 80–90% effective). Body condition (8) was also significantly related to egg presence or absence, but predicted gravidity only weakly. We suggest that a combination of skin incision and hormone analysis provides a fairly good estimate of gravidity. When complemented by mark-recapture techniques and performed on the same individuals at different times of the season, this combination yields estimates not only of the reproductive output of the study population but also of the relative contribution of different females.

A new species of frog of the Eleutherodactylus alfredi group is described from the mountains of Zoquitlán, Puebla, Mexico. It is known from a single adult male only 15.8 mm in snout–vent length. The new species is known from an elevation of 2155 m in oak cloud forest. This new species differs most noticeably from other species in the group by its diminutive size and possessing a suprarostral white-colored patch.

We describe a new species of Tomodon from ridge tops and xeric scrub forests in the southern Andes of Bolivia. The new species most closely resembles T. ocellatus and Pseudotomodon trigonatus. It has more maxillary teeth than either species and also differs in color pattern and meristic characters. The number of maxillary teeth (10–12) in the new species approaches the number in Thamnodynastes, thus blurring the distinction between Thamnodynastes and Tomodon and lending support to recent suggestions that these genera should be synonymized. The geographic and ecological distributions of the new species and Bothrops jonathani overlap, and these species appear to form a Müllerian mimicry system.

The eastern newt, Notophthalmus viridescens, is widely distributed in eastern North America and has been divided into four subspecies. These subspecies differ geographically in morphology and life history, suggesting that the subspecies represent locally adapted and differentiated entities between which gene flow is significantly reduced. We investigated the relationships among subspecies by assessing population genetic structure across the range of the species. We analyzed 18 allozyme loci to examine the evolutionary relationships among the four subspecies of eastern newts: N. v. viridescens, N. v. dorsalis, N. v. louisianensis, and N. v. piaropicola. Despite moderate amounts of genetic variation, phylogenetic and phenetic analyses of the relationships among 12 sites resulted in trees that were inconsistent with the current subspecific classification. Cluster and phylogenetic analyses of allele frequency variation confirmed this, indicating an absence of significant differentiation among subspecies. Instead, populations of N. viridescens appear to cluster into groups representing geographic units that do not directly correspond to the currently recognized subspecies. The morphological and life history differences among the subspecies are not clearly associated with differentiation at allozyme loci. Recent divergence, gene flow, or phenotypic plasticity may explain the lack of correlation between genetic and morphological differentiation.

A new medium-sized species of Hyla from a montane forest in northeastern Brazil is described (snout–vent length in males 37.3–42.2 mm). The new taxon is diagnosed by the following combination of characters: (1) prepollex and prepollical spine present; (2) dorsal color pattern brown, with bright, metallic tan or yellowish triangular spot covering dorsum of snout; (3) supralabial stripe metallic beige, slightly yellowish; (4) dorsolateral stripe bright, yellow, extending from middle eyelid to groin, breaking into series of small contiguous ovoid spots posteriorly; (5) concealed areas of legs and flanks pale cream; (6) tadpole stream-inhabitant. A large proportion of the tadpoles, which are herein described, revealed oral disk abnormalities that could be potentially associated with infection by chytrid fungus. To our knowledge, this is the first published record of a species of Hyla with stream-inhabitant tadpoles in northeastern Brazil.