Animals have evolved a number of ways to protect themselves from the harmful effects of ultraviolet-B (UV-B) radiation, but little is known about the relative importance of different mechanisms protecting amphibian embryos from UV-B radiation. Using enzymatic removal of gelatinous coats (jelly envelope) surrounding the eggs of Rana temporaria, we tested the hypothesis that the jelly envelope acts as a sunscreen that protects embryos from harmful effects of UV-B radiation. We conducted two independent factorial laboratory experiments employing three different UV-B (no UV-B, normal, and enhanced) levels and jelly removal (control, modified, and completely removed) treatments. We found no UV-B × jelly removal treatment interactions in survival rates or in frequency of abnormal individuals, suggesting that jelly removal did not increase susceptibility of embryos to UV-B radiation. These results support the contention that the jelly envelope is not the most important means of protecting R. temporaria embryos from UV-B radiation. Other factors (e.g., melanin pigments, other sunscreen compounds, effective DNA-repair mechanisms) must be responsible for the high UV-B radiation tolerance of embryos.

The stream-type larval forms of the hemidactyliine plethodontid salamanders Gyrinophilus porphyriticus, Pseudotriton montanus, and P. ruber show subtle interspecific variation in pigmentation and body proportions. I tested the hypothesis that morphological divergence is correlated with adaptive diversification in habitat selection by evaluating the ecological distribution and habitat affinities of larvae of these species in the Chattooga River watershed of the southern Blue Ridge Physiographic Province. Pseudotriton montanus was observed in a single habitat, a bottomland swamp in the floodplain of a third-order stream. Both G. porphyriticus and P. ruber showed an affinity for springs, although the latter had a wider distribution in higher-order streams and small ponds. In springs, larvae of G. porphyriticus showed a greater preference for rheocrenes and a proclivity for burrowing in the coarse substrates of these habitats; in contrast, larvae of P. ruber were more common in limnocrenes and helocrenes, which have finer substrates, and were usually observed among decaying leaves or beneath surface rocks and logs. The habitat associations and behaviors documented herein reinforce earlier interpretations of the adaptive significance of morphometric variation among larvae of the three species.

We investigated movement and burrow use patterns from May 1997 through May 1998 in a gopher tortoise population (n = 123) within a 100-ha study site of high quality (old trees, ground cover intact, growing-season fire regime) longleaf pine-wiregrass habitat located in Baker County, Georgia, USA. Telemetered females moved more frequently in summer months (June–October) but traveled longer distances in September than during other months of the 1997 active season. Males exhibited a peak in movement during August and September 1997 that corresponded with mating activity. The longest distance moved between tracking locations did not differ between males and females, but mean distance per move, number of burrows used, and annual home range size were greater in males than in females. The maximum distance moved by an individual during an active season was negatively correlated with female body size but not male body size. No such relationship was found between body size and number of burrows used by either females or males. Similarly, no relationship was found between body size and annual home range area of adult females and males. Our study provides the most complete estimate of annual home range size of gopher tortoises. Because these data describe movements in an area that retains features of the ancestral habitat, these estimates are the best available for designing reserve areas for this threatened species.

Kin discrimination, or the differential treatment of kin, is evident in a wide variety of taxa. The benefits and costs of kin discrimination may vary according to social and ecological conditions, causing discrimination to be context specific. We tested for context-dependent kin discrimination in the red-backed salamander (Plethodon cinereus), a terrestrial species in which adults of both sexes defend feeding territories in which juveniles are often found. If individuals demonstrate the ability to discriminate kin from non-kin, this action would indicate that a mechanism for long-term parental care is present. Mother salamanders may provide protection for juveniles by defending territories from cannibalistic intruders or by feeding on large invertebrates that are predators of juveniles. However, mother salamanders did not significantly discriminate their offspring from unrelated neonates when simple interactions between the two were monitored or when conspecific intruders were added to chambers. Neonates did not behave significantly differently toward mothers than they did toward unrelated females during simple interactions. They also failed to discriminate between substrates that had been scented by their mothers and those that had been scented by unrelated females. When given a choice between related and unrelated neonates, however, females cannibalized unrelated neonates significantly more than their own offspring. This study suggests that kin discrimination between mothers and offspring may occur only in particular contexts, but that mothers possess the mechanism by which they are able to discriminate their offspring from unrelated neonates.

Garter snakes (Thamnophis sirtalis parietalis) in Manitoba court and mate at communal overwintering dens and then disperse to feeding ranges in summer. The restriction of mating activities to den areas may reduce gene flow between populations from adjacent dens, in turn allowing divergence in traits such as antipredator behavior. We quantified responses of adult male snakes to the approach of human observers at four dens, prior to dispersal in late spring. Larger snakes bit us more frequently than did smaller individuals, at all four dens. Although some of the dens were <20 km apart (and hence, individuals from each would likely encounter each other during summer), we found strong geographic differences in antipredator tactics (approach distance and propensity to bite). These differences may reflect genetic isolation of den populations, due in turn to den-based mating and philopatry. However, to rule out alternative explanations such as learned responses to different predation exposure, studies are needed on naïve snakes.

We describe a new species of Hyla from southern Ecuador that is diagnosed by the absence of an omosternum; the presence of an enlarged, curved, and pointed prepollex in males; features of coloration; and an associated suite of presumed anti-predator behaviors. Upon capture, frogs exuded a white, sticky fluid; continued perturbation elicited a defensive posture in which white patches on the posterior sides of the limbs and the vent were displayed. The phylogenetic relationships of H. tapichalaca with respect to the H. armata, H. larinopygion, and H. pulchella groups are discussed.

We redescribe Hyla pulchella joaquini and describe its tadpole and vocalization. The taxonomic status of this subspecies is reevaluated; and on the basis of morphology, geographic distribution, and vocalization, we propose the elevation of this subspecies to specific level with the name Hyla joaquini B. Lutz 1968. We also discuss the relationship of H. joaquini within the species groups of H. pulchella Duméril and Bibron 1841 and H. circumdata (Cope 1871).

Formerly considered a full species, Trimorphodon biscutatus vilkinsonii is presently regarded as a subspecies of T. biscutatus based on morphological data compiled from eight male specimens from southeastern Arizona and southwestern New Mexico; these specimens were thought to be intermediate between the currently recognized T. b. lambda (from Sonora and Arizona) and T. b. vilkinsonii (from Chihuahua and Texas). We performed univariate and multivariate statistical analyses of a morphological data set compiled for T. b. vilkinsonii, T. b. lambda, and specimens collected from the intermediate zone. Our analyses indicate that T. b. vilkinsonii is clearly distinct from T. b. lambda. Several characters, such as blotch width and interblotch distance, allowed more than 95% of specimens of both taxa to be classified properly. Our data also confirm that specimens sampled from the intermediate zone should be considered T. b. lambda. We find the T. b. vilkinsonii populations represent a separate, distinct lineage, and we elevate this taxon to species level.

Hoplocercidae is a small (10 species, 3 genera), poorly known but pivotal family of Central and South American iguanian lizards that has never been the subject of a focused phylogenetic study or systematic revision. We undertake the first rigorous phylogenetic analysis of hoplocercid lizards. We also use our analysis to demonstrate how meristic, morphometric, and polymorphic morphological characters can be coded and combined for phylogenetic analyses using step matrices, which allow continuous variation to be treated as continuous. Parsimony analysis of 46 informative external and skeletal characters (17 qualitative and fixed, 19 qualitative and polymorphic, 8 meristic, and 2 morphometric) yields very different topologies, depending on how the meristic characters are scaled (weighted). Use of between-state scaling yields a phylogeny in which Hoplocercus is at the base of the hoplocercid tree, and Morunasaurus is paraphyletic with respect to a monophyletic Enyalioides. Scaling between characters produces a tree in which Enyalioides is paraphyletic with respect to a clade containing Morunasaurus and Hoplocercus, and Morunasaurus is paraphyletic with respect to Hoplocercus. We also propose a third, “mixed” approach to scaling, which we marginally prefer over the other two methods. This method yields a tree in which Hoplocercus and a monophyletic Morunasaurus make up the sister group to a monophyletic Enyalioides. We discuss the implications of these results for hoplocercid biogeography and evolutionary ecology, tropical speciation, and the phylogenetic analysis of morphological data.

We present phylogenetic analyses of 42 new partial mitochondrial-DNA sequences in combination with 28 previously published sequences representing all eight major groups of the lizard clade Iguanidae (sensu lato). These sequences include 1838 aligned positions (1013 parsimony informative for ingroup taxa) extending from the protein-coding gene ND1 (subunit one of NADH dehydrogenase) through the genes encoding tRNA^Ile, tRNA^Gln, tRNA^Met, ND2 (NADH dehydrogenase subunit two), tRNA^Trp, tRNA^Ala, tRNA^Asn, tRNA^Cys, tRNA^Tyr, to the protein-coding gene COI (subunit I of cytochrome c oxidase). These data, analyzed in combination with 67 previously published morphological characters, provide statistical support for monophyly of iguanid clades Corytophaninae, Crotaphytinae, Hoplocercinae, Iguaninae, Oplurinae, and Phrynosomatinae. Monophyly is neither supported nor statistically rejected for Polychrotinae and Tropidurinae. Polychrotinae* and Tropidurinae* may be recognized as metataxa, to denote the fact that evidence for their monophyly is equivocal, or replaced by recognizing constituent groups whose monophyly has stronger empirical support. A phylogenetically (non-ranked) based, statistically robust taxonomy of iguanian lizards is proposed. The Old World lizard clade, Acrodonta, is composed of Chamaeleonidae and Agamidae* with the Agaminae, Amphibolurinae, Draconinae, Hydrosaurinae, Leiolepidinae, and Uromastycinae nested within Agamidae*. The predominately New World clade, Iguanidae, contains the groups Corytophaninae, Crotaphytinae, Hoplocercinae, Iguaninae, Oplurinae, Phrynosomatinae, Polychrotinae*, and Tropidurinae*; with Anolis, Leiosaurini (composed of the Leiosaurae and Anisolepae), and Polychrus as the subgroups of Polychrotinae*; and Leiocephalus, Liolaemini, and Tropidurini as the subgroups of Tropidurinae*.

We used 1400 bp of mitochondrial DNA sequence from two gene fragments (ND4 and cyt-b) to investigate phylogenetic relationships within Atropoides, with emphasis on the subspecies of A. nummifer. Although many relationships within the genus are strongly supported, monophyly of Atropoides was never supported, although it could not be rejected with statistical confidence. In most analyses, the genus was paraphyletic with respect to Porthidium and Cerrophidion, due to the problematic placement of A. picadoi. Our results suggest that the current taxonomy may underestimate species diversity within this group. Atropoides nummifer was found to comprise three distinct phylogroups, generally coinciding with the current subspecies recognized under A. nummifer but paraphyletic with respect to A. olmec. Additionally, disjunct populations previously thought to represent A. nummifer in Oaxaca, Mexico, and Baja Verapaz, Guatemala, appear to represent A. olmec. We use the phylogeny recovered for A. nummifer and A. olmec to discuss geological and climatic events that may historically have affected gene flow within this complex.

Proctoporus bolivianus is a gymnophthalmid lizard species that occurs at high elevations in the Andes Mountains of southern Peru and Bolivia. Extensive morphological variation in populations collected in the Department of Cusco, Peru, suggested the presence of cryptic species. To assess this possibility, we reconstructed morphological and molecular phylogenies of 13 populations of this species and also used a character-based approach to examine the morphology in more detail. We found P. bolivianus to be composed of three distinct lineages that are separated by substantial genetic distances. We erect two new species to contain unnamed lineages within the P. bolivianus complex. These three species are found within a small geographic area and are likely differentiated because of historical geographic barriers in the extreme landscape of the central Andes.