In this paper we support the division of the previously monotypic genus Ascaphus into two species based on an analysis of 23 allozyme loci from 34 populations. We use maximum likelihood to estimate the Ascaphus phylogeny from the allozyme data and find strongly supported monophyletic Rocky Mountain and Pacific clades. In a nonhierarchal, model-based cluster analysis of the data, each of the 1085 individual genotypes is correctly assigned to either Ascaphus montanus or A. truei with a high probability. We also find a virtually fixed difference between the species at the Pgm-2 locus. Within A. truei, we find a lack of significant pairwise F_ST values among populations from the Coast and central Cascades Mountains, suggesting relatively recent range expansion or contemporary gene flow among these populations. Olympic Mountains populations form a discrete clade in the allozyme topology and are fixed for a unique allele at the Lap locus. These populations remain isolated from the remainder of the species' range based on pairwise F_ST values. The four southernmost A. truei populations each show significant allelic divergence from the remaining populations (based on pairwise F_ST values), suggesting climate-induced isolation. In addition. we extend mtDNA sampling within the Rocky Mountains and sequence 530 nucleotides from the mtDNA Cytochrome b (cyt b) gene in 12 previously unsampled A. montanus populations. This additional sampling defines the geographic extent of a southern mtDNA clade distinguished on average by 0.024 substitutions per site from the northern clade. We use nested clade analysis, a coalescent-based divergence by isolation with migration model (MDIV), maximum-likelihood estimation of the mtDNA topology, and Bayesian model-based genotype assignment, to test predictions from two hypotheses: the western refugia hypothesis, which claims that A. montanus persisted in refugia west of the Snake River during Pleistocene glacial maxima, and the dual refugia hypothesis, which asserts that A. montanus occupied refugia within the Salmon and Clearwater River Valleys during glacial maxima. Our data do not support predictions of the western refugia hypothesis. Nested-clade analysis, estimated dates of lineage divergence supplied by MDIV, and the mtDNA topology support predictions of the dual refugia hypothesis; however, the allozyme topology fails to support some of these predictions. Allozyme and mtDNA data endorse the preliminary recognition of a minimum of two Evolutionarily Significant Units (ESUs) within A. truei: (1) populations from the Olympic Mountains and (2) populations south of the Umpqua River. Two ESUs are also suggested within A. montanus: (1) populations south of the South Fork of the Salmon River, and (2) populations to the north and west of the Salmon River (including the Blue, Wallowa and Seven Devils Mountains). The MDIV analysis indicates an exchange rate of 10 migrants per generation between the northern ESU and the southern ESU.

The daily rhythm of behavioral thermoregulation in sleepy lizards (Tiliqua rugosa) was studied in laboratory thermal gradients under a 12L∶12D photoperiod in autumn and spring. In both seasons, lizards showed distinctive daily rhythms of behavioral thermoregulation, selecting their highest body temperatures during the late photophase and lowest ones during the late scotophase or early photophase. When lizards were subjected to a period of constant darkness at both seasons, this rhythm persisted and free-ran with a period of 24.7 h, indicating that it is an endogenous circadian rhythm. Furthermore, the expression of this circadian rhythm varies seasonally in the amplitude of its free-running rhythm and in the phase at which the minimum T_b is selected during 12L∶12D. The seasonal variation in the expression of the circadian rhythm of behavioural thermoregulation in Tiliqua rugosa lizards is likely to reflect seasonal changes in the neural regulation of this rhythm.

The life history of red-backed salamanders (Plethodon cinereus) has been intensively studied in the United States, but little information exists for Canadian populations, which limits the ability to perform analyses of latitudinal trends in this species. To investigate variations in body size, age structures, longevity, and growth, we used drift fences to sample populations in four habitats (from mixed to deciduous forests) within a 12 km radius in the Mastigouche Reserve located in Quebec, Canada. During the active season of 1997, we captured, measured and sexed (except neonates) a total of 775 salamanders, and estimated the age of 330 of these specimens using skeletochronology. The population characterized by highest mean body size and/or mean age was from a mixed forest that also harbored the greatest abundance of salamanders. For all populations combined, body size (SVL) ranged from 12–46 mm for males and 12–54 mm for females, and longevity reached 8 yr in females and 9 yr in males. Adult males showed lower mean SVL and mean age than adult females (41.0 mm, 5.2 yr vs. 44.8 mm, 5.8 yr, respectively). Accordingly, von Bertalanffy growth models indicated a higher asymptotic body size and a lower growth coefficient in females. For 7 out of 8 analyses, age was significantly correlated with SVL in animals ≥ 4 yr old; the strength of these correlations was greater in females than in males and significantly correlated with SVL range. Comparisons with other populations reveal that age and size at maturity in P. cinereus increase with latitudes in both sexes. However, females, but not males, show a slight increase in mean adult body size with latitudes, leading to a positive allometric relationship between body size and sexual size dimorphism, the northern populations being more dimorphic. Body increment during the first year of growth was found similar to lowest values reported for other small species of Plethodon from the United States but much reduced compared to conspecific populations from the U.S.A. Factors related to latitude (e.g., temperature, duration of activity season) seem responsible for the observed differences.

The use of headstarting and related techniques as management tools for threatened and endangered species remains controversial, due in part to a lack of empirical data on their effectiveness. Here, we present data on pre-natal mortality, growth, and survival during headstarting as well as growth, survival, and reproduction following release for an unprotected population of plains gartersnakes. We combine these data with data on growth and survival of comparably sized wild-caught snakes to provide an overall evaluation of the potential effectiveness of headstarting. Depending on rearing conditions, proportions of live births varied from 0.79 (‘worst-case’) to 0.94 (‘best-case’), survival during headstarting ranged from 0.74 (‘worst-case’) to 0.88 (‘best-case’), and second-year survival following release ranged from 0.11 (‘worst-case’) to 0.40 (‘best-case’). In comparison, survival of free-ranging snakes was 0.16 in their first year and 0.40 in their second year. Assuming the proportion of live births in nature is close to 1, expected survival to reproductive maturity among free-ranging snakes is 0.06, whereas that for headstarted snakes ranges from 0.07 (‘worst-case’) to 0.33 (‘best-case’). The growth rate of headstarted snakes following release was similar to that of similar-sized free-ranging snakes, and headstarted snakes were successful at reproduction. Together, these results suggest that, if carefully implemented, headstarting may be an effective management tool for endangered plains gartersnake populations in Ohio and for other natricine snakes with similar demographic characteristics.

We investigated the reproductive ecology of the western slimy salamander (Plethodon albagula) in an abandoned mine shaft in the Ouachita National Forest of south-central Arkansas. The mine habitat provided an opportunity to observe nesting behavior, quantify reproductive output, and evaluate the influence of precipitation on fecundity for a population of P. albagula that utilize this particular mine shaft to brood and defend egg clutches. We collected reproductive data on 372 clutches between 1982 and 2004. There was no relationship between the number of eggs per egg clutch versus egg size; snout–vent length, body mass, and tail length were not correlated with clutch size. Thirteen females were found to exhibit nest site fidelity, and 10 females exhibited nest securing. Neither nest site fidelity nor nest securing was found to influence reproductive output by females. The amount of precipitation one year prior to oviposition was correlated with the average number of eggs per clutch. It appears, therefore, that precipitation influences fecundity in this population.

A new species salamander of the genus Bolitoglossa is described. It is a member of the alpha group, subgenus Eladinea that occurs in relict subandean forests in the buffer zone area of Tatamá Natural National Park (PNN) on the Eastern slope of the Western Andes of Colombia in the Departamento of Risaralda. This species differs from other species of Bolitoglossa by having basal digital webs with digital depressions on tips of plantar and palmar regions. The basal digital webs are interpreted as adaptation for terrestriality in high mountain salamanders.

We describe a new species of Hypsiboas from the slopes and summit of Auyán-tepui in Canaima National Park, Bolívar State, Venezuela. The new species resembles H. sibleszi, but it differs from that species in having pale green dorsal coloration with numerous small chromatophores, dorsolateral white stripes that extend from the tip of snout to the groin when present, pale interorbital bar absent, a transparent yellow venter, yellow-colored digits and webbing, a more extensive webbing on hands and feet, a prepollical spine not protunding, very narrow nasals partially fused with sphenethmoid, a moderate-sized frontoparietal fontanelle, and an advertisement call consisting of three or four notes with a dominant frequency between 3010 and 3488 Hz. New data on the vocalization, osteology and distribution of H. sibleszi are provided.

A new species of hylid frog is described from the Sierra de Omoa of northwestern Honduras. The new species differs from all other small (<26 mm SVL) Nuclear Middle American hylids in having 7–10 large black spines on the thumb in males and the bones visible through the translucent skin of the posterior part of the dorsum in life.

We describe a new species of Cochranella from cloud forests in La Paz, Bolivia. The new species is assigned to the C. granulosa Group and characterized by the presence of crenulate folds, distinctive coloration, and the first finger shorter than the second. The new species occurs in sympatry with C. spiculata and C. sp.

Based on external morphological and osteological characters, Phrynopus fallaciosus and Phrynopus flavomaculatus are placed in the Eleutherodactylus nigrovittatus Group, and the latter is reported for the first time in Peru (Departamento de Piura). Based on external morphological characters, Phrynopus laplacai is considered to be a junior synonym of P. wettsteini. The type locality of P. wettsteini in Peru is considered as doubtful, and the distribution of the species seems to be restricted to Bolivia. Based on external and internal morphological characters, including comparatively large testes, Phrynopus spectabilis is placed in the synonymy of Pleurodema marmorata. Males of several species of Phrynopus have Finger I (and Finger II in P. cophites) with a nuptial pad, a character that was thought to be restricted to Eleutherodactylus within eleutherodactyline frogs. A new, small species of Phrynopus is described from the Andes in southern Peru.