Females of most of New Zealand's endemic reptiles show low rates of annual reproductive output, involving extended gestation and small clutch size. The main purpose of the present study was to investigate the female reproductive cycle and patterns of clutch size in McCann's Skink (Oligosoma maccanni) from a subalpine site in southern New Zealand (Macraes Flat). The results were then compared with those available for the Common Gecko (Hoplodactylus maculatus) from the same site, where females have biennial reproduction with a gestation of up to 14 months. Palpation was used to assess reproductive condition of O. maccanni noninvasively. A subset of females was then dissected to confirm reproductive condition, determine patterns of change in yolk and embryo mass with pregnancy, and determine plasma progesterone profiles. Both species are lecithotrophic with autumn-spring vitellogenesis; however, in contrast to H. maculatus, female O. maccanni are annual breeders with a spring-summer gestation of 4–5 months. Clutch size in O. maccanni decreases (relative to snout–vent length, SVL) between vitellogenesis (mean 3.33, range 2–5) and pregnancy/birth (mean 2.83, range 1–6). Plasma progesterone concentration is elevated during mid-pregnancy, and lowest during early vitellogenesis. More frequent reproduction at Macraes Flat in the diurnal skink O. maccanni than in the primarily nocturnal gecko H. maculatus in part may be a consequence of different thermoregulatory behavior.

There is a close link between the habitat of an organism and its behavior, performance, and morphology. Many urban parks and gardens are modified such that the ground layer is more open and less complex than the ground layer of a natural bushland habitat. Garden Skinks (Lampropholis guichenoti) are widespread and common throughout the Sydney region, in both modified and more natural habitats. Garden Skinks might, therefore, exhibit differences in behavior, performance, and morphology between these two habitats. We studied behavior (habitat use and response to a predator), performance (sprint speed), and morphology of Garden Skinks in three modified urban garden habitats and three more natural bushland habitats. Lizards in modified habitats spent significantly more time on bare, flat surfaces farther from refuge than lizards in natural habitats. The distance to which an observer could approach a lizard before it fled (approach distance) was generally greater in modified habitats, and lizards in modified habitats had significantly faster sprint speeds than lizards in natural habitats. Lizard morphology (leg length) did not correlate with lizard performance. Apart from lizards at Modified Site 1 and Natural Site 1, lizards exhibited a similar, generalized body shape that was suited to various sprint speeds. However, the ability of Garden Skinks to exhibit different behaviors and performance levels (given similar body shapes) in structurally different habitats in part may explain why Garden Skinks are referred to as a successful “generalist” species.

The Mink Frog, Rana septentrionalis, is closely related and behaviorally similar to the Green Frog, Rana clamitans, and the Bullfrog, Rana catesbeiana, but has a much smaller geographical range and is not as well known. We used mark-recapture and observation techniques to estimate male chorus attendance and site fidelity during the breeding season. We captured, measured, and individually marked 139 males in 2002 and 85 males in 2003. Each male's initial and subsequent positions were recorded using a Global Positioning System. About half the males were never recaptured in either year. Most of the remaining males were recaptured only four times; two males were recaptured more than 10 times. Males were recaptured from subsequent positions as far apart as 90 m and as close as 0.6 m. Males recaptured on consecutive observation nights were in positions less than 15 m apart on average. Although aggressive calling, chasing, and fighting occur when males encounter each other, there is no evidence that male Mink Frogs defend territories over prolonged periods as in Green Frogs and Bullfrogs.

Vocal advertisement by male anurans can make considerable demands on an individual's energetic reserves and innate physiological resources. In this study, we tested for a relationship between calling and locomotory performance in male Gray Treefrogs, Hyla versicolor. Male vocal activity was monitored in choruses assembled in an artificial pond and call duration and pulse effort used as calling performance metrics. Swimming distance served as our measure of locomotory performance. When males were compared within experimental choruses, there was no tendency for the male that produced the longest calls to swim further than the male that produced the shortest calls. Rather, the opposite was true. When these same males were ranked based on their pulse effort, we found that the male with superior calling performance also performed better in the swimming test than the male that gave fewer total pulses. There was no significant relationship between male condition (weight relative to length) and either calling or swimming performance. We hypothesize that pulse effort, which shows more stability within males under dynamic acoustic situations in choruses than call duration, may better reflect limitations of the cardiovascular and respiratory system than does call duration.

Social behavior of Hypsiboas albomarginatus was studied in the Atlantic rain forest, Municipality of Ubatuba, in the north coast of the State of São Paulo, southeastern Brazil. Vocalizations of H. albomarginatus are described, including contexts in which they were emitted and temporal and spectral parameters differentiating advertisement from aggressive calls. Dominant call frequency was inversely correlated with male length and body mass but not with environmental temperature. Number of pulses per note was not correlated with any variable, and advertisement call amplitude was influenced by temperature and time. During chorus aggregation, males interacted acoustically by emitting advertisement calls in antiphony, or by emitting aggressive calls. Some disputes among males culminated in physical combat; males performed kicks and slaps on rivals' heads, in an apparent attempt to dislodge rivals from perches. Visual signals were also displayed during conflicts between males, contributing to an escalation of aggressive behavior. Visual signals were not recorded during courtship between males and females but may help in the accurate localization of the signaling male during aggressive interactions.

Knowledge of the long-term dynamics of freshwater turtle communities is important if we are to understand fully the impacts of human-induced changes in their aquatic and terrestrial habitats. We present data on a turtle community that has been monitored intermittently for more than 20 years and regularly for more than 10 years (1992–2003). The composition of the community has shifted with a decrease in the dominance of Painted Turtles (Chrysemys picta). This shift reflects a decline in the number of C. picta over the past decade, whereas numbers of other species have remained relatively constant. Adult survivorship of C. picta has declined in the past decade. The proportion of C. picta with watercraft propeller damage has increased, whereas propeller damage has remained constant for the two other species for which we have data, the Northern Map Turtle (Graptemys geographica) and the Red-Eared Slider (Trachemys scripta). Our study suggests that the turtle community in Dewart Lake has shifted from 1992–2003. It seems likely that this shift has occurred because of a decline in C. picta, possibly as a result of increased use of the lake by humans.

Comprehensive investigations of thermoregulation have been primarily performed on diurnal lizards. The nocturnal gecko, Hemidactylus turcicus, was used to test a protocol proposed by P. E. Hertz, R. B. Huey, and R. D. Stevenson in 1993. Measures of body temperatures of field active geckos (T_b) and operative temperatures (T_e), the equilibrium body temperatures that animals would attain in given microclimates, were compared to measures of preferred temperatures (T_p) determined in a thermal gradient. Measurements were made on adult males, adult nongravid females, adult gravid females, and juvenile geckos in four seasons (June, August, October, March). Both T_b and T_e varied between seasons; however, T_b closely tracked T_e. No seasonal patterns existed in T_p; however, juveniles had the lowest T_p, whereas gravid females had the highest. Regardless, in all seasons geckos were ineffective thermoregulators. The low variability in T_e is the likely cause for this pattern. For such “thermoconforming” species, we suggest that the magnitude of the variation in T_b, T_e, and T_p be included in assessments of how well organisms regulate to their set-point (preferred), temperatures. We conclude that geckos, and possibly many nocturnal ectotherms, thermoregulate during the day when a more variable thermal environment exists.

Few studies have investigated the emigration behavior of adult ambystomatid salamanders in fragmented landscapes. We assessed the emigration behavior of 30 Spotted Salamanders (Ambystoma maculatum) by implanting transmitters in 2003. Study sites, all in southern Rhode Island, included an active golf course, a golf course under construction, and a closed-canopy forest that served as a control site. Maximum dispersal distances from breeding ponds ranged from 44–467 m (mean = 145, SE = 20 m), with the maximum distance twice as far as prior studies on this species. Spotted Salamanders exhibited distinct preferences for terrestrial habitats by avoiding fairways and selecting forested uplands and forested wetlands. The use of forested wetlands was unusual because most past research has suggested avoidance of this habitat by Spotted Salamanders. We documented adult Spotted Salamanders crossing fairways to adjacent forest patches; thus, fairways were not a dispersal barrier. Compared to random points, adult Spotted Salamanders selected cool microhabitats with greater leaf litter depth, more coarse woody debris, more canopy cover, less herbaceous cover, and high densities of vertical and horizontal small mammal burrows. These results suggest that maintaining extensive upland and wetland forested habitats near breeding ponds, with significant amounts of deep leaf litter, coarse woody debris, and high small mammal densities will help sustain Spotted Salamanders.

The most abundant and diverse records of teiids in the South American Miocene are from early and middle Miocene of Patagonia (Argentina) and Colombia. Only two genera of tupinambines are recognized: Paradracaena and Tupinambis. In this contribution, we describe remains assigned to Tupinambis from the late Miocene Cerro Azul Formation. The fossils were collected in exposures of this unit at several localities in the province of La Pampa, central Argentina. Evolutionary history and biogeography of South American tupinambines were affected by the environmental-climatic change subsequent to the uplift of the Andes. Among the taxa represented in the Miocene, Paradracaena became extinct, whereas Tupinambis survived restricted to environments with a more benign climate, disappearing from Patagonia but not from central Argentina.

A new species of rhacophorid of the genus Polypedates is described on the basis of three adult males and a metamorph from Kerala State, southwestern India. The new species is related to Polypedates cruciger from Sri Lanka, Polypedates pseudocruciger from the Western Ghats of India and Polypedates maculatus from northern Sri Lanka and mainland south Asia. It is diagnosed by the following characters: adult male SVL to 55.1mm; unpigmented nuptial pads on dorsal surfaces of Fingers I and II; vomerine teeth set obliquely between choanae; fingers with rudimentary webbing; no dermal fold along forearm; webbing on Toe III reaching disks at tip of digit; absence of a conical lingual papilla; skin of forehead free; snout lacking a dermal flap; heel lacking a cutaneous spur; and a dark hour-glass-shaped pattern on dorsum.

We describe activity patterns, diet, reproduction, sexual dimorphism, and thermal ecology of the semiaquatic teiids Crocodilurus amazonicus and Dracaena guianensis, from two localities in the Brazilian Amazon. Most C. amazonicus were first sighted in water or on open ground, were active during the hottest hours of the day, and usually had low body temperatures associated with substrate temperatures. Dracaena guianensis were found mainly perching on shrubs and used higher perches located closer to the center of lakes compared to C. amazonicus. Both species appear to rely primarily on crypsis to escape detection by predators but will dive into water as a final means of escape. Crocodilurus amazonicus has a broad diet which includes terrestrial and aquatic prey, particularly spiders and hemipterans, whereas D. guianensis feeds primarily on aquatic snails. No association between body dimensions and prey dimensions was evident. Sexual size dimorphism was not significant in either species, contrary to results reported for other teiids elsewhere, but males of C. amazonicus had relatively longer bodies and tails than females. Clutch size of both species was small relative to their body size and relative to other Amazon teiids, apparently influenced by their semiaquatic habits and by locomotor constraints. We found reproductive females during March (wet season) and July (dry season), suggesting an extended reproductive season.

Basin building, a rare reproductive strategy used by frogs, consists of constructing a depression in the substrate (a basin) and depositing eggs within the basin. The stream breeding Neotropical hylid frog, Smilisca sordida, constructs several types of basins; specifically, eggs deposited in a circular depression either with eggs floating on the surface of the water or with eggs attached to the substrate (open basins) or eggs buried beneath the substrate (a buried basin). Two hypotheses were tested to explain the selective forces maintaining the basin construction reproductive mode in S. sordida. The microenvironment modification hypothesis proposes that basins modify the environment in ways beneficial to developing young. The predator avoidance hypothesis proposes that basins separate and therefore protect embryos and larvae from predators. The thermal prediction of the microenvironment modification hypothesis is supported but only for open basins: buried basins do not modify the thermal environment relative to streams. Fish consume eggs of S. sordida, suggesting that basins provide refuge from fish predation. Field data on predation rates show that, although basin building may reduce predation by fish, planarians, other invertebrate species, and conspecific tadpoles, all colonize basins and consume eggs of S. sordida. Of 230 clutches, 37.4% experienced total mortality and of clutches that failed, 74.4% were solely caused by predators that colonized basins. The distribution of predators along the stream was nonrandom and the distribution of predators strongly influenced the fate of clutches. Basin desiccation, as well as flooding, caused additional mortality to young and are additional consequences of depositing eggs in basins for S. sordida.

Most studies on orientation of movements of pond-breeding salamanders have considered only a single local population (or breeding pond) during ≥1 yr, or multiple populations during a single year. We quantified migratory patterns of Marbled Salamanders at nine breeding ponds during 5 yr in western Massachusetts. Based on captures at drift fences, movements were nonuniform at all breeding ponds. In addition, the direction of orientation differed among breeding ponds and changed slightly across years. Within ponds, orientation of adults and juveniles differed significantly in 52% of comparisons, and adult movements were more directionally concentrated than those of juveniles. In addition, migrating salamanders shifted slightly the orientation of their movements as they traveled into uplands, suggesting that migration routes are spatially complex and that determination of migration “corridors” based on concentrated captures at the pond periphery may be misleading. Although salamanders used migration routes with higher canopy cover, our models did not explain a large portion of the variation in orientation, and protecting areas of high canopy cover alone may not be sufficient as a protection strategy. Our results suggest that movement routes, though perhaps concentrated in the short term, are unpredictable in the long term. Thus, we can offer little evidence that distinct corridors can be identified and protected that would be used consistently over time by migrating or dispersing Marbled Salamanders. Consequently, until we better understand mechanisms governing movements in this species, a conservative conservation strategy would require protecting broad terrestrial areas around breeding sites.

Organisms can diverge in life history when introduced outside their native range due to release from predators, competitors, and parasites, and also due to genetic drift and local adaptation. We studied the ecology of the American Bullfrog (Rana catesbeiana) in its introduced range in British Columbia (BC). To assess differences between introduced and native populations, we compared the population ecology of BC bullfrogs to published life-history parameters from the bullfrog's extensive native range in eastern North America. In BC, bullfrogs emerged from hibernation in late April and early May. Breeding choruses developed fully when air temperatures exceeded 20°C. Eggs were laid from mid-June to mid-July when the mean water temperature was 20°C. Mean egg mass size was 13,014 ± 7,296 eggs (mean ± standard deviation). Tadpoles hatched in 3 to 5 days and overwintered the first year as tadpoles. Approximately 68% of the tadpoles metamorphosed at the end of the following summer, but the remaining spent a second winter in the pond. Bullfrogs were large enough to attain sexual maturity 2 yr after metamorphosis. Bullfrog population density among ponds varied from 4.1 to 530 frogs/ha. Terrestrial insects were the primary prey item of bullfrogs < 150 g, whereas frogs were the primary prey item of larger bullfrogs. The life-history parameter values estimated for BC bullfrogs were within the range observed for bullfrogs in their native habitats. Due to milder weather conditions in southwestern BC, the seasonal pattern and growth rate of bullfrogs were similar to lower latitude populations in Kentucky and Missouri. We found no evidence to support the hypothesis that when released from native predators and parasites bullfrogs build up to unusually high population densities or attain significantly larger sizes in their introduced range.

A new bufonid toad is described. The species belongs to the genus Melanophryniscus, and may be the largest species in this genus. Its size and external features (pale green in dorsal surface) resemble those of Melanophryniscus cambaraensis and Melanophryniscus macrogranulosus, from which it differs by the absence of frontal swelling. At present, the new species is endemic to the southern border of the Brazilian Southern Plateau, in central Rio Grande do Sul state.

I describe habitat use, diet, and male and female reproductive cycles of Takydromus sauteri, an oviparous grass lizard inhabiting Orchid Island, a tropical island off the southeastern coast of Taiwan. All T. sauteri were observed on leaves of Japanese silver-grass (Miscanthus floridulus) at the forest edge. The diet of T. sauteri consisted mostly of spiders (35.7%) and Hemipterans (14.3%). Two prey categories, spiders and gymnoceratans, numerically dominated the diet. Two lizards' stomach contained plant seeds, and two had eaten roaches. Mean snout–vent length (SVL) of adult males (N = 59) was 64.2 (range: 60.3–73.7) mm and that of females (N = 63) was 67.1 (range: 50.6–76.5) mm. Females exhibited spring and summer vitellogenesis with parturition occurring from February to August. Onset of vitellogenesis showed a negative correlation with mass of female fat bodies. Females produced one to four eggs per clutch, and clutch size was not correlated with SVL. Two clutches were recorded during a single year in some individuals. Male fat bodies exhibited the lowest mass from January to July, coincident with the period of reproductive activity.

The South American water snake Helicops leopardinus is very abundant in the Pantanal wetlands of Central Brazil. We studied the biology of this species based on specimens collected by local workers in the Paraguay River. Females attained greater body lengths and had larger heads than males, but the latter had longer tails. Helicops leopardinus fed on a wide variety of fishes (70% of the total prey items) and frogs, with fishes of the order Gymnotiformes (33.34%) and frogs of the family Hylidae (23.34%) representing the most common prey items. There was relatively low diet overlap between the sexes and between juveniles and adults. Mean litter size was 6.6 and ranged from 4–11. The reproductive cycle was seasonal, with birth occurring late in the wet season (simultaneous with the flooding of the Paraguay River), facilitating dispersal of young snakes by floating vegetation. Floating vegetation may be a critical habitat for H. leopardinus, and management plans for their maintenance need to be developed.

We investigated microhabitat selection by Terrapene carolina carolina in a North Carolina mountain wetland. We monitored a total of 21 radio-tagged turtles in 1997 and 1998. Turtles were located at least weekly from mid-May until they entered their overwintering sites. Microhabitat characteristics were quantified at each turtle location and at a corresponding random location < 25 m away. Weather varied during the study: 1998 was much hotter and drier than 1997. Microhabitat did not differ between males and females, except that females selected form locations with greater amounts of exposed soil. Overall, turtles constructed forms in areas that were more humid than the surrounding environment. Box turtles also used habitats with lower surface temperatures and higher humidity levels than the surrounding environment, particularly during hot and dry periods. This likely helped them regulate body temperature and prevent desiccation. During the summer of 1997 and all monitoring seasons in 1998, turtles were located at sites with moderate canopy cover and less understory plant cover than expected. Sites with less understory cover may have greater air circulation than those with more cover, thus allowing turtles to dissipate heat more rapidly. Amounts of woody debris, leaf litter, and canopy cover at turtle locations were similar to those available in the surrounding environment. Our results indicate that the attributes most important for defining the microhabitat of T. carolina (surface temperature, relative humidity, and understory plant cover) are related to thermoregulation and minimizing water loss.

Although females of oviparous snake species presumably would benefit by modifying their thermoregulatory behavior while gravid, few studies have investigated whether gravid females actually thermoregulate differently than nongravid conspecifics in the field. To this end, we recorded body temperatures (T_bs) from female Eastern Foxsnakes (Elaphe gloydi) housed in a large seminatural enclosure using temperature-sensitive radio-transmitters. Contrary to our expectations, gravid females did not maintain higher or less variable T_bs than nongravid females. We suspect that the thermal environment available to gravid females at our site may render further increases in thermoregulatory effort, beyond that of nongravid females, unnecessary and potentially detrimental, given possible costs of thermoregulation.