Morphology of some groups of organisms has been highly conserved over evolutionary time, resulting in genetically divergent taxa with relatively little morphological variation. Genetic studies on salamanders of the genus Plethodon have revealed a high level of morphologically cryptic diversity, and recent ecological and evolutionary studies have suggested that morphology may be informative for taxonomic purposes when combined with genetic data. We examined morphological variation in the Ouachita Mountain endemic salamanders P. fourchensis and P. ouachitae to test whether these sister species, and recently identified phylogeographic lineages within species as defined by genetic data, can be discriminated using morphology. We found that P. fourchensis and P. ouachitae differed significantly in morphology and could be classified correctly with greater than 90% accuracy. Individuals from a previously identified hybrid zone were morphologically intermediate to the two parental species. Phylogeographic lineages within each species (n  =  4 for P. fourchensis, n  =  7 for P. ouachitae) also exhibited significant morphological differences and were classified correctly in 57–72% of cases. Our results support genetic evidence that showed significant divergence between P. fourchensis and P. ouachitae and among the different lineages within each species. The high levels of diversity within P. fourchensis and P. ouachitae have important implications for conservation because these endemic species have small ranges and lineages are usually restricted to single mountains.

Much attention has been given to the conservation of small populations, those that are small because of decline, and those that are naturally small. Small populations are of particular interest because ecological theory suggests that they are vulnerable to the deleterious effects of environmental, demographic, and genetic stochasticity as well as natural and human-induced catastrophes. However, testing theory and developing applicable conservation measures for small populations is hampered by sparse data. This lack of information is frequently driven by computational issues with small data sets that can be confounded by the impacts of stressors. We present estimates of demographic parameters from a small population of Boreal Toads (Anaxyrus boreas) that has been surveyed since 2001 by using capture–recapture methods. Estimates of annual adult survival probability are high relative to other Boreal Toad populations, whereas estimates of recruitment rate are low. Despite using simple models, clear patterns emerged from the analyses, suggesting that population size is constrained by low recruitment of adults and is declining slowly. These patterns provide insights that are useful in developing management directions for this small population, and this study serves as an example of the potential for small populations to yield robust and useful information despite sample size constraints.

Detailed observations on interactions between parasites and prospective hosts during the infection process can clarify (1) the routes by which parasites enter the host and (2) the ability of prospective hosts to detect, avoid, or resist potential parasites. Such information can clarify determinants of host vulnerability. Infective larvae of the nematode Rhabdias pseudosphaerocephala entered the bodies of their anuran host the Cane Toad (Rhinella marina, formerly Bufo marinus) primarily through the orbit (i.e., by crawling over the surface of the toad's eye) rather than by burrowing through the skin (believed to be the usual route of infection for rhabditid parasites). In our experimental infections, metamorph Cane Toads detected infective R. pseudosphaerocephala larvae but did not avoid them, nor did they manage to restrict rates of infective larvae penetration by using behavioral means (the toads kicked at infective larvae but failed to dislodge them). Rhabdias pseudosphaerocephala cause damage to their toad host during the process of host entry and throughout the ensuing infection. Despite the high cost of infection and the low cost of avoidance, metamorph Cane Toads seem to lack effective parasite avoidance strategies.

Prey may use a variety of strategies to avoid predators, including behavioral modification and inducible defenses. For an inducible defense to evolve, one necessary component is that the defense must be costly; if it is not, then the defense should evolve into one that is always expressed (i.e., a constitutive defense). However, costs of inducible defenses have not been well-documented. Using predator exposure experiments in aquatic mesocosms, we demonstrate that dark tail coloration (or lack thereof) in Blanchard's Cricket Frog (Acris blanchardi) tadpoles is an inducible defense. Specifically, Acris tadpole tail spots in treatments with dragonfly predators (Anax sp.) were significantly larger when compared to treatments with fish predators (Lepomis macrochirus). However, tadpoles in control tanks (with no predators) had tail spots that were not significantly different in area from the Anax treatment. Therefore, this defense is unique among those known because the presence of fish induces the loss (not the appearance) of this morphology. Because Acris tadpoles express the tail spot in the absence of predation risk, this phenotype also does not appear to have any substantial allocation cost. We also document predation of Acris tadpoles by a fish predator and demonstrate reduction in movement and differential habitat use in the presence of fish predator cues. Under predation risk, tadpoles became less active and occupied the shallowest regions of their habitats. This combination of plastic morphological and behavioral defenses likely allows these frogs to successfully breed in a broad range of aquatic habitats with different assemblages of predators. While likely effective in reducing vulnerability to Anax attacks, the tail spot may increase vulnerability to fish. Our results suggest that the antagonistic effects of predator-specific inducible defenses may represent another type of cost relevant to the conditions under which inducible defenses are expected to evolve.

This study investigates the mechanical implications of shell shape differences between males and females of two North American turtle species: Chrysemys picta and Glyptemys insculpta. These species show patterns of sexual dimorphism that are common to many species of turtle. Females have wider and more highly domed shells, whereas males tend to have flatter, more streamlined shells. In addition, the males of many terrestrial species have concave plastra, most likely to accommodate the domed shells of the females while mating. The purpose of this study was to determine whether the known morphological differences in male and female turtle shells are also associated with differences in shell strength. Landmark coordinate data were collected from the shells of males and females of both species. These data were used to create digital models of each shell for finite-element (FE) analysis. FE models were generated by transforming a single base model of a turtle shell to match the shapes of each specimen examined in this study. All models were assigned the same material properties and restraints. Twelve load cases, each representing a predator's bite at a different location on the carapace, were applied separately to the models. Subsequently, Von Mises stresses were extracted for each element of each model. Overall, the shells of females of both species exhibited significantly lower maximum and average stresses for a given load than those of their male counterparts. Male G. insculpta exhibited significant increases in stresses because of the concave shape of their plastra. We suggest that the mechanical implications of shell shape differences between males and females may have a large impact on many aspects of the biology of these turtle species.

We conducted a genetic study of the largest cluster of US federally threatened Gopher Tortoise (Gopherus polyphemus) colonies. Our objectives were to (1) identify genetic variation within and among colonies across the landscape; (2) determine which factors are important in affecting genetic variation, including land use, habitat quality, and population size; and (3) determine whether genetic partitioning among populations exists and how this relates to (a) geographic distance between sites, (b) Gopher Tortoise natural history and spatial ecology, and (c) land-use history. We studied genetic variability of nine microsatellite DNA loci for 340 adult tortoises from 34 colonies separated by 1.3–45.1 km across a 56,000-ha military installation. Overall genetic variation was low across the landscape and within colonies. Observed heterozygosity (H_O) of tortoise colonies was 49% and allelic richness was 52% of that found in populations located in the eastern portion of the species distribution where habitat is naturally more continuous. Our single colony with highest genetic variation had H_O that was 57% and allelic richness that was 60% of eastern colonies. Genetic variation was greatest in sites with suitable habitat. We found weak to no genetic structure across the 45-km landscape (F_ST  =  0.031; D_ST  =  0.006) and evidence for only one genetic group (K). Although landscape reconfiguration to create sites for military activity has redistributed tortoise colonies and home ranges, we concluded that weak population structure is natural across our study area. Comparison to similar results from a cluster of connected eastern colonies suggests this is a general characteristic of tortoises across large, continuous landscapes and that populations are composed of multiple colonies across the landscape and are naturally large in spatial extent. To alleviate the tortoise–human land use conflict on Camp Shelby, Mississippi, USA and to ensure these created areas continue to benefit tortoises in the long term, maintenance of forest habitat surrounding these created open areas is required. We recommend managing tortoises at Camp Shelby as one unit.

Frequency-dependent predation (FDP), or apostatic selection, is often assumed to be a main evolutionary process to maintain color-pattern polymorphism, particularly when colors are drab. Under this hypothesis, differences in survival rate based on color pattern should be detectable. In many species of anoles, females show variation in dorsal patterns. These patterns consist of drab colors and are thought to have evolved as a predator-avoidance mechanism. We tested the FDP hypothesis for Norops humilis at the La Selva Biological Station in Costa Rica. Three female patterns are found in this population. The dotted pattern occurs in males as well as females, whereas vertebral stripe and reticulated morphs are only found in females. To test FDP, we compared morph frequencies from population data collected at several sampling periods between 1981 and 2007, expecting to see fluctuations in frequencies over time. In addition, we predicted that the most common morph would experience higher mortality. Therefore, we analyzed survival rates from a capture–recapture study. We found that the dotted morph was more common in juveniles as well as in adults and adult morph frequencies remained stable over time. Survival rates supported this, showing no significant difference among morphs. The evidence supported rejection of the FDP hypothesis in this population of lizards. Possible scenarios to explain the stability of dorsal patterns and suggestions for future research are presented.

The Flint Hills region of Kansas and Oklahoma encompasses the largest, contiguous tallgrass prairie in North America and is an important conservation area for many tallgrass-prairie species. We conducted a radiotelemetry study with the use of temperature-sensitive transmitters to characterize the spatial ecology of two species of snakes within a portion of this contiguous grassland. We monitored Eastern Yellow-Bellied Racers (Coluber constrictor flaviventris) from 2006 to 2008 and Great Plains Rat Snakes (Pantherophis emoryi) from 2007 to 2008 at the Konza Prairie Biological Station in the northern Flint Hills. Although racers (mean  =  67.3 ± 10.6 m, n  =  12) and rat snakes (mean  =  41.3 ± 4.7 m, n  =  12) differed in the distance moved per day, they did not differ significantly in home-range size. The minimum convex polygon (MCP) home range averaged 11.45 ha (SE  =  3.06, n  =  12) for racers and 15.06 ha (SE  =  2.48, n  =  12) for rat snakes. By analyzing the autocorrelation of locations (Mantel correlograms), we found that racers exhibited irregular movements, whereas rat snakes exhibited long periods of inactivity between directed movements. The body temperatures of racers were significantly greater in woody (30.7 ± 0.4°C) than in grassy habitats (29.8 ± 0.3°C). The body temperatures of rat snakes were significantly greater aboveground (26.9 ± 0.3°C) than underground (26.1 ± 0.2°C). Our study benefits the conservation of native snakes by elucidating space requirements and providing a baseline for comparisons between contiguous and fragmented landscapes.

A new species of the Bokermannohyla pseudopseudis group similar to B. alvarengai and B. itapoty is described from Serra do Cabral, Espinhaço Range, Minas Gerais, southeastern Brazil. It is diagnosed by having a medium size (male 47.3–54.8 mm; female 44.5–48.6 mm); short snout, truncate in lateral and dorsal views; head 1.01–1.07 times wider than long; tympanum 0.08–0.09 times snout–vent length (SVL); hypertrophied forearm; well-developed prepollex; nuptial pad small, with two separate areas covered with small keratinized spiculae, on medial and lateral edge of the base of the prepollex; dorsal color pattern composed of dark gray blotches of irregular shape on a light gray background, without a central light spot, resembling lichens incrusted on rocks; dark gray perpendicular bars covering the whole dorsal surface of thighs, rarely branched, without light spots, highly contrasted with the background color; and the lack of a white stripe over the vent.

We describe a new species of Gastrotheca from the Río Abiseo National Park of the San Martín Region in the Andes of northern Peru. The description is based on a series of 29 specimens that were collected between 1989 and 1999 at two localities (Pampa del Cuy, Alpamachay) in the wet puna of the national park between 3380 and 3470 m elevation. The new species has a snout–vent length of 46.9–57.7 mm (53.5 ± 3.0) in females (n  =  21), and 35.3–43.8 mm (41.6 ± 3.2) in males (n  =  6). In life, the dorsum is pale grayish brown with reddish-brown paravertebral markings or blotches, and the venter is cream. Females have a single median, dorsal brood pouch and release tadpoles in water as indicated by two specimens found at Gosner Stages 45 and 46. The new species is distinguished from all of its congeners by having the dorsum with two reddish-brown paravertebral markings bearing prominent longitudinal ridges and warts. The new species differs from the two other species of Gastrotheca (G. ossilaginis, G. phalarosa) known from the Region San Martín by lacking integumentary-cranial co-ossification (present in G. ossilaginis), by having the skin on dorsum with prominent longitudinal ridges and warts (dorsal skin shagreen in G. ossilaginis), and in producing tadpoles (direct development in G. ossilaginis). The new species most closely resembles G. phalarosa. Both species produce tadpoles, have fingers and toes with lateral fringes, and Finger I larger than Finger II. Gastrotheca phelloderma differs from G. phalarosa by having the skin on dorsum with prominent longitudinal ridges (absent in G. phalarosa), the venter granular (smooth except granular on posterior part of belly and proximal posteroventral surfaces of thighs in G. phalarosa), a palmar tubercle (absent in G. phalarosa), a long and distinct inner tarsal fold (barely evident on distal fifth of tarsus in G. phalarosa), and the throat and belly grayish tan (black with white spots in G. phalarosa).

We describe a new species of lizard in the genus Gekko from Sibuyan Island in the Romblon Island group of the central Philippines. Although the new species is diagnosed from other Philippine Gekko by body size and shape, coloration, and multiple characteristics of external morphology, additional support for the recognition of the Sibuyan Gekko population as a distinct evolutionary lineage is garnered from DNA sequence data and biogeographical inference. The new species has been collected on trunks of trees or on granitic rocks along rivers in mature, lowland forest, and on vegetation at forest edges bordering agricultural areas. It is known only from Sibuyan Island and is undoubtedly endemic to this single small, isolated landmass. Although the larger, topographically complex islands of the Philippines have been the targets of numerous recent efforts to estimate vertebrate species diversity, smaller islands of the archipelago have received comparatively less attention and may support significant levels of underappreciated vertebrate diversity.

The Turks Island Boa (Epicrates c. chrysogaster) is endemic to the Turks and Caicos Islands and is currently known from only 11 islands. The subspecies has likely been extirpated from several islands in its historic range, and all remaining populations are threatened with extirpation owing to habitat loss, introduced feral predators, malicious killing, and vehicle strikes. To assist conservation efforts, we undertook a genetic analysis of 53 individual E. c. chrysogaster, representing five island populations, with the goal of identifying existing population structure and genetic diversity. For each snake sampled, we sequenced one mitochondrial and two nuclear genes, resulting in 1591 bp of sequence, and screened nine microsatellite loci. All individuals were found to be monomorphic at the four microsatellite loci that amplified, and only three individuals were found to vary (by a single nucleotide polymorphism) in either nuclear gene. Nine mitochondrial haplotypes were found, with a maximum sequence divergence of <1%. Taken together, these data indicate shallow genetic divergence in this subspecies, possibly owing to a lack of historical population structure and small population size when the Turks and Caicos Banks were each single islands during the last glacial maximum. Epicrates c. chrysogaster appears to represent a single evolutionarily significant unit, a significant finding suggesting that conservation strategies focusing on ecologically intact populations might be more appropriate than alternate strategies involving near-impossible reversal of declining populations on heavily disturbed islands. In addition, reintroduction programs would likely not disrupt any significant historical population structure.