We conducted behavioral trials to determine if egg preference by female northern dusky salamanders (Desmognathus fuscus) is influenced by the developmental age of their eggs. Within 72 h of oviposition, we divided 41 clutches in half and monitored the time the female spent with each of the genetically similar half-clutches. We then reared the eggs for 21 days in darkness under two temperature regimes (13 and 23 C) to produce a developmentally advanced and delayed half-clutch for each female. Initially, females divided their time almost equally between half-clutches. After thermal manipulation of embryo development, females spent the majority of their time with the developmentally advanced half-clutch. Of the 25 respondents included in the second trial, 21 spent >60%, and 15 spent more than 80% of their time in the presence of developed eggs. We hypothesize that females assess the developmental status of their eggs in order to optimize the tradeoff between the costs and benefits of parental care.

Several internal and external factors can influence escape behavior in lizards. We studied the escape behavior of four Phrynosomatid lizards (Urosaurus bicarinatus, Sceloporus gadoviae, S. anahuacus, and S. mucronatus) from México. Each species exhibited a unique combination of escape behaviors. Urosaurus bicarinatus had short approach and flight distances, and used squirreling (running to opposite side of tree or rock) when approached. Sceloporus gadoviae had a short approach distance, a large flight distance, and often used squirreling. Sceloporus anahuacus had a short approach distance, an intermediate flight distance, and typically fled under a nearby rock. Sceloporus mucronatus had large approach and flight distances, and ran under large rocks when approached. Males and females of all species did not differ in approach or flight distance. Reproductive status had no effect on approach or flight distances for the species where reproductive status was assessable (S. anahuacus and S. mucronatus). Body size did not influence either approach distance or flight distance for any species. Temperature had little effect on flight and approach distance except for S. gadoviae where warmer lizards tended to have shorter approach distances. Lizards that escaped capture used warmer sites than those that did not escape. We caught >75% of U. bicarinatus and S. gadoviae, 67% of S. anahuacus, and only 38% of S. mucronatus. Catchability appeared to be influenced by temperature (intraspecifically) and by approach and flight distance (interspecifically). While escape behavior of these lizards was generally not affected by internal or external conditions, our results suggest the ability of lizards to escape capture potentially depends on internal and external conditions (e.g., temperature).

The microenvironment surrounding a lizard egg will strongly influence its probability of hatching, yet little is known about which environmental cues females use to select favorable nest sites. We conducted three experiments using Norops polylepis (Polychrotidae) in semi-natural enclosures to determine a female's ability to assess soil moisture levels and the presence of leaf-litter cover when selecting an oviposition site. Females laid significantly more eggs in moist soil (42% water content) than in the dry (10%) and saturated (70%) soil treatments. Most eggs (72%) placed in moist soil treatments hatched, whereas none of the eggs in the dry and saturated soil treatments hatched. In a separate choice experiment, females laid significantly more eggs in a “soil-and-leaf-cover” treatment than in “soil-only” or “leaf-cover-only” treatments. Our results demonstrate that female N. polyelpis can detect variations in water content and leaf cover, and that females prefer microhabitats that likely maximize the survival of their eggs.

To examine environmental effects on age structure, growth rate and body size, we studied three epigean populations (490–2350 m a.s.l.) and one subterranean (550 m a.s.l.) population of the Pyrenean newt Euproctus asper. The age structures were measured by skeletochronology of phalanges. In the three surface populations, where winter dormancy on land causes an annual growth stop, lines of arrested growth (LAGs) were observed. LAGs in the subterranean population, where individuals stay in the water throughout the year, indicate yearly (at least cyclical) periods of arrested growth even though animals occupy a relatively constant temperature/light environment. The age structures of adults did not differ between surface populations (5–28 yr) and the subterranean population (7–16 yr). Body lengths were highest for the surface population from the lowest altitude. The age, body size and growth traits of the subterranean population came closer to the values obtained for the surface population located at 490 m a.s.l. than for those living at higher altitudes. We hypothesize that LAGs in subterranean newts result from reduced feeding in winter and that the similarity of age and size structures of subterranean and low-altitude populations argues for a recent colonization of the hypogean environment, where populations can find remaining optimal environmental conditions favorable to these stenothermic and rheophilous animals.

Complete characterization of lizard foraging behaviors may require information about aspects rarely measured. Most studies record only number of movements per minute (MPM) and/or percent of time moving (PTM), but lizards differ markedly in average speed (AS) and speed while moving (MS) during foraging and in proportion of attacks initiated after detecting prey while the lizard is moving (PAM). We present data on these variables for nine lizard species and on foraging speed for several others, permitting first assessments of relationships between speed, PAM, and both phylogeny and foraging mode; examination of the effect of body length on foraging speed; and correlative analyses of relationships between foraging variables. Although sprint speed may increase with body size, foraging speed did not, presumably for two reasons. Because search speed is much lower than sprint speed, as is speed of movement between ambush sites, searching efficiency and stamina may be more important determinants of foraging speed than is sprint speed. Second, the body size range was small, allowing the possibility that foraging speed may vary with body length over the much larger size range between the smallest and largest species worldwide. Nevertheless, a large majority of lizard species are in the size range tested, suggesting that body length may not strongly affect foraging speed except when extremely short or long species are included in comparative analyses. High PAM, high AS, and low MS were characteristic of autarchoglossans and active foragers, whereas low PAM, low AS and high MS were exhibited by iguanians and ambush foragers. In independent species analyses, significant correlations were observed between several pairs of foraging variables. In analyses using phylogenetically independent contrasts, the only significant finding was a strong positive correlation between PAM and PTM. Although these findings suggest that foraging speed, MPM, and either PTM or PAM may provide independent measures of foraging activity needed to adequately describe interspecific variation, this conclusion is tentative due to the small sample size of limited taxonomic breadth.

We analyzed the iliosacral joint and iliolumbaris muscle anatomy of the species of Pseudinae, based on the two types of articulations defined by Emerson. Unusual characters should be expected in the pseudine iliosacral articulation structure, given their aquatic habits and evolutionary history. In fact, the presence of a ligamentous cap joining the ilium with the sacral diapophysis has not been described previously, and may be unique to pseudines. This particular group lacks a single pattern of iliosacral articulation for the whole subfamily, and the articulations are not strictly referable to any of the types or subtypes described by Emerson. The iliosacral articulation is interspecifically variable within Pseudinae and is intermediate between the articulations of Type IIA and IIB.

We describe a new species of Ischnocnema from upper montane rainforest in La Paz, Bolivia. Unlike its congeners, the new species possesses notched ungual flaps, a short dorsolateral fold, and a small axillary gland. The new species resembles I. sanctaecrucis and is the third species of Ischnocnema known from Bolivia.

A distinctive new species of the colubrid snake genus Heteroliodon is described from the deciduous dry forest of Montagne des Français, near the northern tip of Madagascar. The new species is characterized by stout habitus, low number of ventral scales, long relative tail length, high number of infralabial scales, and absence of a light colored vertebral stripe. The limestone massif of Montagne des Français appears to be an important center of endemism for Madagascan biota and should, therefore, be included in Madagascar's network of nature reserves.

A new species of Bufo is described from cloud forests of the Cordillera de Apolobamba, La Paz, Bolivia. The new species has large glands on dorsal surfaces of shanks and forearms and is tentatively included in the B. spinulosus group.

Two new species of frogs of the Eleutherodactylus alfredi group are described from Subtropical and Montane Wet Forests of the Montañas del Mico and the Sierra de Caral of the Caribbean slopes of Guatemala. They differ from other Guatemalan species in the group by having the fifth toe pad wider than the second, few melanophores on the abdominal area of the venter, and dorsal and ventral ground coloration. The species from the Sierra de Caral is larger in overall size and has smaller dentigerous fascicules than the one from the Montañas del Mico. These two species also differ between themselves in dorsal and ventral ground coloration.

Nine species of Gastrotheca primarily have allopatric distributions in the Andes of northern Peru. A new species with integumentary-cranial co-ossification is described from montane forest in the northern part of the Cordillera Central in the Departamento de Amazonas, Peru. A second new species from the same area lacks integumentary-cranial co-ossification and differs from all other members of the genus by having a black venter with white spots.

A new species of Bufo tentatively assigned to the Bufo veraguensis group is described from forests near Paucartambo de Pasco, Peru, at elevations of 2600–3000 m in the Cordillera Oriental of central Peru. The new species differs from all known bufonids by having numerous large glands with many keratinous tips on the dorsum, large glands on the tibia and forearm, and two large dorsal glands lying between the parotoids. The new species is most similar to Bufo chavin. Both species are compared to each other and B. veraguensis with respect to external characters and skull osteology. The tadpole and call of the new species remain unknown.

A new species of the Eleutherodactylus discoidalis group from the Andean humid montane forests of Departamento La Paz, northern Bolivia, is described. The new species differs from other species of the group by having regularly warty dorsal skin, a small tympanum, slightly enlarged, rounded digit discs, and uniformly dark brown coloration. Data on the advertisement call of the new species and an operational key for the species of the E. discoidalis group are provided.

The genus Proctoporus sensu stricto is a poorly known gymnophthalmid lizard clade distributed across the Andes of southern Peru and Bolivia. Recent collecting efforts in central and southern Peru recovered specimens and tissues of all known members of the genus, enabling the first complete phylogeny of the genus to be constructed. In addition, a new species was found in Puno, Peru and is described herein. We analyzed DNA sequences of three mitochondrial genes using maximum parsimony and Bayesian MCMC methods to reconstruct a phylogeny of the group. The phylogeny suggests an ancient split between a newly discovered lineage from Puno and the remaining species that coincides geographically with its isolated range. Proctoporus pachyurus and P. sucullucu form sister species; P. bolivianus forms a clade with P. unsaacae P. guentheri. The elevationally restricted ranges of all known Proctoporus species likely have contributed to the high species diversity found in southern Peru. Both allopatric and parapatric modes of speciation are proposed to explain the diversification of Proctoporus species.