Otago Skinks (Oligosoma otagense) are some of New Zealand's largest and most rare lizards. The movements and home ranges of these skinks were investigated using radio-telemetry at the Redbank Reserve near Macraes Flat, Central Otago, New Zealand. Thirteen Otago Skinks were tracked from December 2003 through April 2004 for 26–111 days. There was no significant difference in the distance or frequency of movements between sexes. Home ranges estimated for all individuals using the 100% Minimum Convex Polygon method varied from 200–5,400 m². Male home ranges were significantly larger than female home ranges, and nongravid females had significantly larger home ranges than gravid females. There was a considerable amount of home-range overlap and interaction between individuals. Human capture of skinks, the most common method for the monitoring this species, increased the frequency of movements. Capture-induced disturbance caused skinks to increase the frequency of movements in the days immediately following the event. The results of this study will be used in the future conservation management of the Otago Skinks.

The influence of trap placement on capture rate is poorly documented in herpetological studies and requires consideration, because optimizing trap sets can increase detectability of target species and improve capture rates generally. We conducted pitfall trapping for four species of terrestrial lizard in duneland, shrubland and farmland on Kaitorete Spit (South Island, New Zealand). Over 4,800 trap-days, 536 captures of 401 lizards were made. Five microhabitat factors were measured and tested for their ability to influence capture rates of Oligosoma maccanni and Oligosoma nigriplantare polychroma. Generalized linear mixed models revealed that the strongest overall influence on capture rate was the distance separating pitfall traps from the nearest cover (the greater the distance, the lower the capture rate). Weaker, positive influences on capture rate included the amount of vegetation cover surrounding traps and the presence of divaricating shrub and vine species, with some correlations between variables. Capture rates of O. maccanni and O. n. polychroma were highest in duneland and farmland, respectively. Our results show that simple measures such as placing pitfall traps close to cover, will improve capture rates for at least some species of New Zealand endemic skinks. Where such relationships are known in advance, trap placement may be deliberately manipulated to increase capture rates and standardized between sites to improve the validity of using capture rates as indices of relative density. Further research is needed to assess the effect of trap placement for other species and in relation to other factors that influence capture rates.

The number of simultaneously attacking simulated predators and their approach speeds and angles affected escape trajectories and flight initiation distance in Balearic Lizards (Podarcis lilfordi). Our findings confirmed predictions prey flee in directions maximizing distance from predator(s). During slow approaches, escape angle was 45° when approached by two predators at right angles and 90° when approached from opposite directions. Escape at close to 45° by lizards approached at slower speed by a single predator supports the hypothesis that prey use escape trajectories allowing them to visually monitor predators. Flight angles were closer to being straight away from a predator during faster approaches, suggesting that distance maximization may be more important than monitoring predator position when risk is great. When predators approached from opposite directions, flight angle shifted away from the faster predator, suggesting that lizards may have equalized risk from both predators based on positions and speeds. Flight initiation distance was greater for approach by predators side by side than by one only during faster approaches, suggesting that risk is a joint function of predator number and speed. Flight initiation distance was greater when predators approached at right angles than side by side, perhaps because of difficulty of monitoring multiple predators in different locations. Distance fled did not differ among treatments and may have been affected by distance to refuge. Thus, Balearic Lizards adjusted flight initiation distance and escape trajectories in ways that enhanced their abilities to avoid predation during simultaneous approaches by two predators.

We investigated the effects of incubation temperature (29°C, 31°C, and 33°C) on total length (TL) and body mass (BM) of Caiman latirostris, a crocodilian with temperature-dependent sex determination (TSD), at hatching (N  =  180) and in a sample of hatchlings (N  =  40) after one year of raising. Size at hatching was strongly clutch-specific. Animals incubated at 31°C (100% females) were larger than at 29°C (100% female) and 33°C (100% males). Absolute growth to one year was higher for females (eggs incubated at 29°C and 31°C) than for males (eggs incubated at 33°C). The possibility that constant 33°C incubation temperature had compromised embryological development cannot be rejected. If so, it confirms that high incubation temperatures can have long-lasting effects on posthatching growth. If not, possible advantages of females growing more rapidly than males are discussed.

Teiid-like scincomorphan lizards from the Late Cretaceous (Campanian) of the Kaiparowits Formation of southern Utah include Chamops cf. Chamops segnis, cf. Leptochamops, a new species of Meniscognathus, and a new taxon with well-developed tricuspid teeth. These taxa comprise some of the only confirmed reports of these types of lizards from Late Cretaceous rocks south of Wyoming, allowing for a more comprehensive investigation of the distributional and evolutionary patterns of teiid-like scincomorphans from the Campanian. The majority of the known taxa are from the Western Interior west of the margin of the midcontinental sea that bisected North America during the Late Cretaceous. The teiid-like scincomorphans from the Campanian comprised two distinct faunas; one in the north (e.g., Montana, Western Canada) and one in the south (e.g., Utah, New Mexico). These two faunas share Chamops and potentially Leptochamops, but each region also has two to four endemic taxa representing a diversity that correlates to latitudinal differences. Teiid-like scincomorphans present in North America prior to the establishment of the midcontinental seaway are not nearly as diverse as during the Campanian, indicating that the radiation of forms followed the establishment of the seaway, although it may not have played a direct role.

A new species of Tantilla is described from a single specimen obtained from Volcán Ceboruco, southern Nayarit, Mexico. The new species closely resembles other species of the Tantilla calamarina group. With the addition of the taxon described herein, the calamarina group now contains seven species, T. calamarina, Tantilla cascadae, Tantilla coronadoi, Tantilla deppei, Tantilla sertula, Tantilla vermiformis, and the new species described herein. Collectively, members of the group are distributed along the Pacific versant of Middle America in three disjunct regions: (1) from northern Sinaloa to Guerrero, including the Tres Marías Islands; (2) the Balsas Basin of Morelos, Puebla, Distrito Federal, and the State of Mexico; and (3) from El Salvador to northwestern Costa Rica. We provide a small list of specimens collected in the highlands of Nayarit, and report Lithobates psilonota, Ambystoma rosaceum, Elgaria kingi, Plestiodon lynxe and Rhadinaea hesperia for the first time from the state. We report the second specimen of T. sertula, known previously only from the holotype.

A new, lowland species of the Ingerophrynus biporcatus group is described from the Endau-Rompin National Park in southern, peninsular Malaysia, Johor. It is unique in various aspects of morphology and color and is the third, new herpetological species discovered and described from this region of the Malay Peninsula since 2005. This suggests that the biodiversity of this part of southern Malaysia may be significantly underestimated and underscores the importance of continued field research in these lowland forests which are currently being logged and converted to oil palm plantations.

Increasing evidence shows that alkaloids in the skins of poisonous frogs are sequestered from a specialized diet of ants. It is considered likely that in the small aposematic bufonid genus Melanophryniscus, skin alkaloids are taken up via a similar system. However, quantitative aspects of the diet in this genus remain poorly studied. As a result, studies that correlate diet and skin alkaloids in these toads are precluded by the lack of extensive information on the diet of most species and populations within the genus. We describe diet composition of Melanophryniscus rubriventris with a particular focus on geographic variation over much of its range distribution in northwestern Argentina and compare the diet of this species with that of other members of the genus. The diet of M. rubriventris was composed of 17 arthropod prey categories. The species consumed primarily small, gregarious prey such as ants, mites, aphids, burrowing bugs, and beetles. Diet composition of the populations studied was similar in the number of prey categories, but we found noticeable interpopulation variation in the proportion of each prey item consumed. Earlier works had reported that ants, collembolans, and mites were prominent in the diet of other Melanophryniscus. Our study indicates that, although ants are common prey, they are not the main prey category in all populations.

Two new species of Calamaria (Colubridae: Serpentes) are described from Buton Island, southeast Sulawesi, Indonesia. The first species is distinguished from all other Calamaria by the combination of no preocular scale, mental not touching anterior chin shields, five supralabial scales and five scales or shields surrounding paraparietal, no more than 28 subcaudals, tail long and tapering to a point, nine modified maxillary teeth, and uniform body coloration. The second species is distinguished from all other Calamaria by the combination of no preocular scale, mental not touching anterior chin shields, four supralabial scales, and five scales or shields surrounding the paraparietal. Both species are litter dwelling, semifossorial snakes and occur in monsoonal rain forests.

Understanding the timing of movement events of pond-breeding amphibians to and from breeding and natal ponds, respectively, is essential to implementing effective conservation and monitoring strategies for this group of vertebrates. In this study, we assessed the emigration timing of newly metamorphosed juveniles of four species of pond-breeding amphibians (Ambystoma maculatum, Ambystoma opacum, Notophthalmus viridescens, and Rana sylvatica) in western Massachusetts from data collected at 14 seasonal ponds during four consecutive years (2000–2003). Results identified emigration “windows” for juveniles of each species during each year and for all years pooled. Additionally, analyses identified considerable intraspecific variation in the timing of emigration among ponds and years for at least three of the four study species. Our results are directly applicable to management strategies (e.g., road-closures) aimed at minimizing human-related impacts (e.g., road mortality) on populations of pond-breeding amphibians, as well as to mitigation strategies (e.g., maintaining engineered wetlands with an appropriate hydroperiod length) employed in cases of direct habitat loss.

We conducted nocturnal surveys of postmetamorphic Ascaphus truei on six streams in north coastal California from 2002–04, using mark-recapture techniques to determine sizes of age classes, growth rates, site fidelity, reproductive chronology, and seasonal activity within the stream channel and riparian zone. Ascaphus truei grew year-round, but grew faster during the summer (1.47 ± 0.06 mm/month) than winter (0.89 ± 0.04 mm/month). Growth curves indicate that following metamorphosis, females likely reached sexual maturity in three years, whereas males became reproductive in two years. Tailed frogs in these coastal streams exhibited limited within-channel longitudinal movement (x¯  =  13.6 m), although movements were highly variable (range  =  0–112 m). Significantly more frogs were captured in summer than fall, and very few frogs were captured in winter. Significantly more reproductive adults were captured in spring than summer, suggesting that breeding occurred primarily in spring. Recapture data indicated that females deposited eggs in the stream mostly during July and August and may have a biennial reproductive cycle. This study has quantified life history traits for A. truei populations in coastal northwestern California that contrast to results for inland and northern Ascaphus populations. Comparative geographic variation studies throughout the range of Ascaphus are needed to aid in understanding life-history and ecological differences both within and among regions.

We describe a new species of Anolis from the highlands of western Panama. The new form is phenetically similar to lemurinus-group Anolis, especially to Anolis pachypus and Anolis tropidolepis. It differs from these two species in possessing fewer loreal scale rows, larger middorsal scales, and a solid red dewlap. We present a phylogenetic analysis of the new species and find that it nests within mainland Beta anoles as sister species to A. tropidolepis.

A new species of hylid frog, from the genus Scinax, is described from Ilha de Porcos Pequena at the southern coast of São Paulo State, southeastern Brazil. The new species belongs to the Scinax perpusillus species group and is diagnosed by the following set of characters: moderate-size (males 16.2–18.8 mm SVL, female 18.8–20.6 mm SVL); canthus rostralis distinct and well defined; V-shaped depression between nostrils; eyes protruding and prominent, glandular skin surface of legs. This new species is found only on Ilha de Porcos Pequena, an island of approximately 24 ha and, therefore, is threatened because of restricted range size and susceptibility to habitat modification.

Nonbreeding habitats are critically important for Rana draytonii, especially for individuals that breed in temporary bodies of water. We radiotracked 123 frogs to evaluate seasonal habitat use. Individual frogs were continuously tracked for up to 16 months. Some individuals remained at breeding ponds all year, but 66% of female and 25% of male frogs moved to nonbreeding areas, even when the breeding site retained water. Frogs at our main study site moved 150 m (median), roughly the distance to the nearest suitable nonbreeding area. The greatest straight-line distance traveled was 1.4 km, although the presumed distance traveled was 2.8 km. Females were more likely than males to move from permanent ponds (38% of females, 16% of males), but among dispersing frogs, males and females did not differ in distance moved. Some frogs left breeding sites shortly after oviposition (median  =  12 days for females, 42.5 days for males), but many individuals remained until the site was nearly dry. Fog provided moisture for dispersal or migration throughout the summer. Our data demonstrate that maintaining populations of pond-breeding amphibians requires that all essential habitat components be protected; these include (1) breeding habitat, (2) nonbreeding habitat, and (3) migration corridors. In addition, a buffer is needed around all three areas to ensure that outside activities do not degrade any of the three habitat components.

Chemoreception is a common mechanism used by many species to detect the presence of a potential predator and subsequently respond to it. The perceived risk of predation may force retreat to suboptimal conditions, forcing a trade-off between the risk of predation and the ability to acquire resources. Responses to chemical cues of predators vary as a result of past experience, ontogeny, or reproductive state. The basking regime maintained by gravid females of the viviparous skink, Eulamprus tympanum, may directly alter sex ratios of offspring produced through temperature-dependent sex determination. The avoidance of predator scents may restrict basking ability and, in turn, alter the sex of offspring produced. We measured responsiveness to chemical cues using tongue flicks as an indicator of chemical discrimination in adult females and neonates and in females of different reproductive condition. We then measured activity rates and basking behavior of females in experimental enclosures in the presence of various chemical stimuli to determine whether basking opportunity is compromised by the presence of a predator scent. Neonates respond significantly more than nonreproductive adult females to all chemical stimuli suggesting an age-specific shift in response, whereas adult females respond differently depending upon reproductive state. Under laboratory conditions, gravid females modify their behavior and forego the opportunity to bask when there is a perceived predation risk. However, further experimentation conducted under field conditions would be necessary to test fully the hypothesis that basking opportunity is compromised by the presence of a predator stimulus and, in turn, could alter offspring sex ratios.

Caiman latirostris (Broad-Snouted Caiman) is one of two crocodilian species that inhabit Argentina. Wild populations of C. latirostris in Santa Fe Province are under management by Proyecto Yacaré (MAGIC-MUPCN), a program based on a ranching system whose goal is the sustainable use of the species, together with its habitat conservation. We used 233 random amplified polymorphic DNA (RAPD) markers to obtain preliminary data about population structure and genetic variation in four populations of C. latirostris in Santa Fe province, which may be used to provide a genetic framework of conservation units to evaluate, and perhaps to modify, current plans for its sustainable management. Our results suggest low to intermediate levels of mean heterozygosity (H), mean number of alleles per locus (A), and percentage of loci polymorphic (P). Furthermore, the values of Nm and F_ST seem to show low levels of gene flow and some population subdivision. Distance genetic analysis appears to reveal high similarity between Estancia El Estero, Costa del Salado, and Estero del Paraje 114 populations, and results of analysis of molecular variance indicate that nearly all variation exists within populations rather than among them, implying that a great number of alleles is shared among populations. New samplings and new measurements in parameters such as H, A, and P, should be carried out in future years to confirm the genetic structure and level of population differentiation and to make new decisions about the management plan that has been successful in the recovery and conservation of C. latirostris.

We studied the diet, niche breadth and overlap, and feeding behavior of two sympatric species of Aromobatidae, Allobates marchesianus and Anamaloglossus stepheni, from the Central Amazon. We studied the diet composition based on type and size of prey items and compared the diet between species (1987–88) and with prey availability in the habitat for A. stepheni (1997). We studied the distribution of feeding activities throughout the day and movement frequency, foraging speed (distance covered while foraging), and foraging frequency (number of feeding attempts per time) for both species. Activity peaks occurred from 0600–1200 h. Both species showed similar diets and feeding behavior, consuming Formicidae and Collembola as well as small food items (1.0–1.9 mm) in higher proportions. Movement frequency, foraging frequency, and speed were also similar for both species. Diptera, Collembola, Araneae, and Acari were preferred by Anomaloglossus stepheni, whereas Coleoptera and Formicidae were avoided. Anomaloglossus stepheni selected prey items measuring 1.0–1.9 mm, whereas they appeared to avoid items measuring 2.0–2.9 mm and ≥4 mm. Allobates marchesianus and Anomaloglossus stepheni had very similar feeding ecology at the study site in regard to foraging behavior and diet composition. Diet composition was also very similar between populations of A. stepheni studied in different time periods at the site, suggesting some stability either in prey availability or food selection. Our results suggest that, even being related and using the same habitat, these species do not diverge in their feeding habits.

A new species of Chaunus, apparently related to Chaunus arenarum, Chaunus rubescens, and Chaunus achavali is described. The new species occupies Cerrado habitats in southwestern Piauí and Bahia states and in northwestern Minas Gerais state, Brazil. The species is characterized by anterior interruption of the supraocular crest; weakly developed cranial crests; short and robust limbs; several pointed spiculae on dorsum, head, and limbs; male coloration; small to medium size; and by the short and narrow head.

Despite the large amount of work on frog mating systems, the potential role of predators as an agent of selection on breeding adults has received very little study. Here, I use data from multiple populations of Pacific Treefrogs (Pseudacris regilla) to demonstrate that sexual selection from mating success favors larger males, but natural selection from predation by giant water bugs favors smaller males. Additionally, I found no relationship between male body condition and mating success or predation risk. This result demonstrates that predation is a potentially important agent of selection that counteracts sexual selection in anurans.

The formation of amphibian population structure is directly affected by predation. Although aquatic predators have been shown to have direct negative effects on larval salamanders in laboratory and field experiments, the potential impacts of gape-limited fish on larval salamander growth has been largely underexplored. We designed an enclosure experiment conducted in situ to quantify the effects of gape-limited Brook Trout (Salvelinus fontinalis) on larval Northwestern Salamander (Ambystoma gracile) growth. We specifically tested whether the presence of fish too small to consume larvae had a negative effect on larval growth. The results of this study indicate that the presence of a gape-limited S. fontinalis can have a negative effect on growth of larval A. gracile salamanders.

We investigated effects of observers and stream flow on Northern Two-Lined Salamander (Eurycea bislineata bislineata) counts in streams in Acadia (ANP) and Shenandoah National Parks (SNP). We counted salamanders in 22 ANP streams during high flow (May to June 2002) and during low flow (July 2002). We also counted salamanders in SNP in nine streams during high flow (summer 2003) and 11 streams during low flow (summers 2001–02, 2004). In 2002, we used a modified cover-controlled active search method with a first and second observer. In succession, observers turned over 100 rocks along five 1-m belt transects across the streambed. The difference between observers in total salamander counts was not significant. We counted fewer E. b. bislineata during high flow conditions, confirming that detection of this species is reduced during high flow periods and that assessment of stream salamander relative abundance is likely more reliable during low or base flow conditions.

We documented population densities, microhabitat preferences, desiccation rates, and diets of Sphaerodactylus vincenti on St. Vincent, West Indies. We predicted and observed high densities (to 5,625/ha) in moist, shaded leaf-litter. Such microhabitats provide refuges, access to prey, and protection against water loss, because S. vincenti is vulnerable to high desiccation rates. We found significant differences in mass-specific water-loss rates and body mass between conspecific populations at differing elevations, with larger geckos less resistant to water loss living in more mesic environments at higher elevations. Stomach content analysis suggests that S. vincenti is a dietary generalist that feeds on a variety of small arthropods primarily by day.

A calcified pseudodontoid in the mandibular symphysis of Leptodactylus troglodytes was described from fresh, macerated, and cleared/double-stained preparations. Histology confirmed that the pseudodontoid was mineralized and composed of fibrocartilage. This structure was found in all specimens of both sexes, suggesting a role in either prey capture or defense rather than in courtship or combat. The structure in L. troglodytes differed morphologically and histologically from the pseudodontoid observed in other Leptodactylus and in other neobatrachian species. Our sampling indicates that the presence and morphology of the pseudodontoid is synapomorphic to a clade recently named Tinctanura. However, a broader sample is still necessary to strengthen this assessment.

Histological examination of long bones from wild American Alligators (Alligator mississippiensis) reveals weakly defined growth zones and extensive fibrolamellar bone formation in both healthy and stressed adult individuals. The discovery of this tissue in wild adults of variable health status challenges three current assumptions concerning fibrolamellar bone in crocodylians: first, that it can only be formed in juveniles; second, that it occurs only in captive animals; and third, that it occurs only in individuals experiencing optimal physiological conditions. This highlights the need for further detailed study of bone microstructural diversity among modern crocodylians. Moreover, these results have potentially far-reaching implications for studies of fossil archosaurs, which often draw on extant crocodylian models, and for the phylogenetic significance of fibrolamellar bone within Archosauria as a whole.