Populations of unisexual Ambystoma salamanders typically consist of ploidy-variable individuals (diploid through pentaploid) that differ in their proportional representation within the populations. These salamanders reproduce using a method that has been termed kleptogenesis: stealing genetic material from males of compatible bisexual Ambystoma species (e.g., Jefferson Salamanders [A. jeffersonianum] and Blue-spotted Salamanders [A. laterale]). Kleptogenesis can result in ploidy-variable embryos within an egg mass because the unisexual female might or might not incorporate the male genome. Little is known about the survivorship of individuals having different ploidy levels. Triploid individuals are most abundant, indicating that higher ploidy individuals (tetraploids and pentaploids) are either produced more rarely, or suffer higher mortality than triploids. We assessed the frequency of ploidy levels (determined by microsatellite analysis) across four life-history stages over 2 yr: adults, early larvae, late larvae, and metamorphosed juveniles. We found that warmer breeding-season temperatures were correlated with an increased frequency of high-ploidy individuals being produced. In addition, there was a gradual decline in tetraploids across all stages as the larvae developed into adults. Breeding season temperature and selection against certain ploidy levels both appear to be important drivers of unisexual salamander population composition at our study site.

Vocalizations are important for female attraction and territory delimitation in prolonged breeding anurans. Males of Hypsiboas prasinus display year-round nocturnal calling activity, using herbaceous and bushy vegetation along the margins of ponds as calling sites. We monitored the temporal pattern of calling activity from July 2011 to June 2012, and vocalizations were recorded for bioacoustical analysis. We quantified the physical parameters for four of the five types of vocalizations found in this species: an introductory advertisement call (Type A call), a chorus advertisement call (Type B call), a resuming activity advertisement call (Type C call), and an agonistic call. Calling activity was spread throughout the annual cycle and there was no correlation between air temperature and calling activity. This finding indicates that the calling pattern is controlled predominantly by behavior and not physiology. During the cold dry season, some individuals were observed to shift their calling sites to the water surface, causing vocalizations to be lower pitched and longer.

Mark–recapture studies are often used to quantify rates of recruitment and survival, growth rates and patterns, and individual movement, among other things. Marking techniques must satisfy several criteria—marks should: (1) not affect the behavior or survival of individuals; (2) not cause undue pain or stress; (3) last as long as the study; and (4) be easily identifiable. Visible implant elastomer (VIE) tags can be used to mark vertebrates, including amphibians, but can move under the skin, potentially affecting readability and resulting estimates of dispersal and survival. We examined the effectiveness of VIE as a marking technique for Common Mistfrogs (Litoria rheocola) in the field over 1 yr. We determined the readability of marks over time, and evaluated effects of marking on measurements of frog movement. If marking affected mobility of the marked rear limb, we expected that subjects marked in both legs would be more strongly affected (thus, individuals should move less often), or should move shorter distances, than subjects marked in only one leg. We marked 1392 animals under the skin of the thighs in either the right, left, or both legs and recaptured 255 subjects at least once. We found that 84% of marks remained readable after 1 yr. Movement parameters were very similar between frogs marked in one or two legs. We conclude that VIE is a safe and effective marking technique for long-term amphibian studies, especially for stream-associated hylid frogs.

Western Pond Turtles (Actinemys [Emys] marmorata) occur in habitats ranging from large rivers and reservoirs to small streams and ponds, as well as from sea level to about 2000-m elevation. This range of environments can affect population parameters such as body size, growth rates, survivorship, and reproductive output. We marked 321 individuals in 287 trap-days in 2007 and 2010 at a high-elevation pond on the southern flank of the Tehachapi Mountains in Southern California, USA. The population was female-biased (92 F:78 M in 2007, 113 F:60 M in 2010), and estimated to contain 412 individuals. Growth rates were relatively high compared with other populations of A. marmorata. Monthly survivorship was 0.989–1.000 for adults and juveniles and sλ values denoted a stable population. Clutch size averaged 6.3 eggs, and we found 22 instances of intra-annual double-clutching, and possibly a third clutch for one female. Population traits of turtles at this high-elevation pond differed little from turtles at lower elevation sites at the same latitude. Despite conservation threats to this species, this population is indicative that A. marmorata can survive well in small habitats, many of which are human-created, and this has increased the amount of habitat for the species as other natural areas have been eliminated.

Many animal species use stereotyped displays to attract the opposite sex and to intimidate same-sexed rivals. Research aimed at understanding display recognition, function, and usage can be aided through the use of animal robots that allow one side of signaler–receiver interactions to be controlled. Manipulation of displays in ways that do not occur in nature has the potential to determine the boundaries of display recognition, as well as to provide insights into the manner in which animal display contests are structured. We describe two experiments that extend previous work on display recognition in the lizard Anolis grahami. In the first experiment, we used robots to determine the relative importance of body coloration and headbob display structure for species recognition. The results showed that subjects responded more strongly to robots having both conspecific appearance and display structure than to robots that deviated in those characteristics from the conspecific stimulus. In the second experiment, we explored the effect of removing display components on subjects’ responses, where subjects witnessed a conspecific robot exhibiting a typical display (headbobs followed by dewlap pulses), or a deficient display consisting only of headbobs or dewlap pulses. Contrary to expectation, subjects in the headbobs-only treatment spent more time headbobbing than dewlapping in response; whereas, those in the dewlap-only treatment spent more time dewlapping than headbobbing. Interactive robots could be used in future investigations of the functions of different display components, as well as to examine the rules by which lizard display contests are conducted in nature.

Green Anoles (Anolis carolinensis) are comprised of red-dewlapped (RD) forms that are found throughout the southeastern USA and a gray-dewlapped (GD) form that is restricted to southwest Florida. Prior research has shown that RD A. carolinensis produce headbob displays of three distinct types that differ primarily in their temporal patterns. Based on known morphological, physiological, and genetic differences between GD and RD populations, we hypothesized that these populations also would differ in headbob display structure. To test this hypothesis we quantified 440 displays from 39 males (24 GD and 15 RD) and assigned displays to type using numerical decision criteria. Although comparison of the same display types between GD and RD males revealed differences in the durations of several homologous display units (i.e., bobs or interbob pauses), only one unit differed following statistical correction for multiple comparisons. By taking into account all display variation in both populations simultaneously, however, discriminant function analysis correctly assigned display units with high accuracy to population and display type. Nevertheless, differences in unit durations often were greater between two RD populations occurring within Florida than they were between our GD and RD study populations. Thus, despite our demonstration of differences in the display temporal structure between GD and RD forms of A. carolinensis, these differences appear to be no greater in magnitude than those observed between RD populations.

Diurnal lizards are useful model organisms for the study of color polymorphisms. The cellular basis of nonavian reptilian coloration and dermal chromatophores, as well as the different pigments contained therein, is relatively well understood. Nonetheless, specific predictions cannot be made for the biochemical chromatophore constituents of individual species a priori. Despite well-documented associations between throat coloration and behavioral, physiological, and life history traits, the cellular basis of throat coloration in polymorphic Common Side-Blotched Lizards, Uta stansburiana, has never been studied. We used a combination of chromatographic techniques in conjunction with transmission electron microscopy and a thin-layer reflectance model to determine the cellular basis of polymorphic coloration in U. stansburiana. We found that different morphs express coloration through varying spatial arrangements of dietary xanthophylls (lutein and zeaxanthin), differential synthesis of drosopterins, differential melanin synthesis, and morph-specific iridophore reflecting platelets. Our results indicate that chromatic variations in this polymorphism cannot be attributed to alternative xanthophore pigmentation or structural reflectance alone. Instead, the chromatophores of U. stansburiana are multicomponent color signals.

The introduction of nonnative plant species might generate habitat modifications that, in turn, increase the predation risk for animals, either by making prey species more conspicuous, limiting the availability of refuges, or by offering vantage points to potential predators. We compared predation pressure and escape behavior of two sympatric species (Liolaemus wiegmannii and Liolaemus multimaculatus) of Sand Lizards inhabiting forested and nonforested grasslands of the pampasic coastal sand dunes of Argentina. Predation pressure was evaluated by measuring the predation rate on plasticine replicas of lizards and the abundance of avian predators. We also recorded flight initiation distance (FID) of lizards in the different habitat types and the microhabitat used as refuge. Both lizard species prefer refuges in native plants but, when they are scarce, the nonnative Acacia longifolia is selected as alternative refuge. In forested habitats, sand-burying behavior is a complementary strategy used by L. multimaculatus to avoid predation. The FID of L. wiegmannii was greater in forested habitats than in nonforested ones. In contrast, L. multimaculatus exhibited a short FID in forested habitats, mostly because sand-burying behavior appears to reduce the risks typically associated with exposed areas. Plasticity in antipredatory behavior suggests that these lizards could recognize predators and develop a suitable antipredatory behavior. We conclude that increased predation pressure and structural alterations of the habitat in the presence of nonnative A. longifolia affect the decisions that determine how, when, and where these lizards flee.

We provide a well-supported phylogenetic hypothesis for all recognized lineages of the Liolaemus kriegi complex based on a multilocus dataset. We used 29 individuals from the eight taxa included in this complex for which we sequenced eight gene regions (two mitochondrial and six nuclear). We implemented maximum likelihood and Bayesian inference methods for the mitochondrial, nuclear, and concatenated sequences and employed BEAST to estimate the species tree. The all genes concatenated analyses and the species trees recovered the L. kriegi complex as monophyletic with high support, including three described species (L. kriegi, Liolaemus ceii, and Liolaemus buergeri) and three previously identified candidate species (Liolaemus sp. A, Liolaemus sp. C, and Liolaemus sp. D), with Liolaemus tregenzai as a closely related taxon. Another previously proposed candidate species (L. sp. B) has a labile topological position that varies depending on the type of markers and analytical methods used. In the mitochondrial gene tree, L. sp. B is recovered within the L. kriegi complex whereas in the “all genes concatenated” analyses and in the nuclear species tree analyses, it is recovered outside of this complex as sister to Liolaemus petrophilus (a representative of the L. petrophilus group). Morphologically, L. sp. B is indistinguishable from L. austromendocinus (also included in the L. petrophilus group); thus, we do not consider L. sp. B as part of the L. kriegi complex. We estimated divergence times for the major clades of the complex based on the species tree hypothesis, and all were inferred to have a Pleistocene origin.

A species with populations that occur in variety of habitats might be expected to exhibit variation in morphological traits across its distribution. Based on our examination of 95 specimens of Bunopus tuberculatus (Squamata: Gekkonidae) collected across its range within Iran, we describe the geographic variation in meristic traits and morphology. Values for traits were compared using principal component analysis and discriminant function analysis. None of the populations showed sexual dimorphism in morphometric or meristic characters. One-way analyses of variance revealed that differences exist in most characters among populations. Additionally, canonical variable analyses indicate that the sampled populations of B. tuberculatus are divided into four distinct forms: (1) western and southwestern populations, (2) southern populations, (3) the population of Bampoor, and (4) eastern populations. Our results provide a comparative baseline that will help to resolve the complicated taxonomy of B. tuberculatus across the rest of its distribution in southwest Asia and the Arabian Peninsula.

We describe a new species of Cnemaspis from southern Sumatra, Indonesia. The new species is the first Cnemaspis reported from Sumatra and is a large (52.6–58.7 mm in snout–vent length [SVL]) nocturnal species. A combination of the following characters distinguishes the new species from all other Southeast Asian congeners: adults reaching 58.7 mm SVL; supralabials 13 or 14; infralabials 11 or 12; tricarinate ventrals; precloacal pores absent; moderately prominent, randomly arranged, dorsal tubercles; 20 or 21 paravertebral tubercles; no tubercles on lower flanks; caudal tubercles encircling tail; subcaudals keeled; the median row of subcaudals not enlarged; two postcloacal tubercles on each side of tail base; no enlarged femoral, subtibial, or submetatarsal scales; subtibial scales keeled; 28–34 subdigital lamellae on fourth toe; dark and light caudal bands distinct in both sexes. We tentatively assign the new species to the Cnemaspis kendallii group of the Southern Sunda clade of recent phylogenetic analyses.