We analyzed 621 lizard fecal pellets to assess the diet of the endemic lizard Gallotia galloti (Lacertidae) throughout one year in the thermophilous scrubland, the most threatened habitat in the Canary Islands. Indicating the importance of frugivory, 98.1% of pellets contained seeds from fleshy-fruited plant species (8,028 seeds in total), and the fruit volume reached 47.5%. The Canarian endemic plants Rhamnus crenulata and Canarina canariensis were most important in frequency of occurrence and number of seeds found in pellets, respectively. Lizards were more frugivorous during the summer (63.0% of volume), and seasonal variation was associated with temporal changes in availability of ripe fleshy fruits. We detected microspatial differences in the consumption of fruits and plant material. Significant correlations were found between plant cover of each species and their respective consumption by lizards. Lizards consumed invertebrates throughout the year; Formicidae, Hemiptera, Coleoptera, and Hymenoptera were the most frequently consumed prey (76.5% of the animal prey items). Our results indicate that G. galloti is one of the most frugivorous lacertids studied. The high number of undamaged seeds removed by these lizards also implies an important role in the seed dispersal processes of many fleshy-fruited plant species from this threatened habitat.

Information on the importance of captive turtles as sources of human Salmonella infections is well established; however, data on the potential of free-ranging turtles as carriers of salmonellae are scarce and contradictory. We combined traditional culture techniques and molecular tools to analyze swabs obtained from the cloacae and from different body parts of captive and free-ranging turtles for salmonellae. Salmonellae were detected in 50% of captive turtles (N = 10). A similar percentage of detection (51%) was obtained for salmonellae in free-ranging turtles from the Rio Grande (N = 80) with six sites at Big Bend National Park, Texas, and one site at Elephant Butte Reservoir, New Mexico, analyzed. Here, 46% of Trachemys gaigeae (N = 36), 56% of Apalone spinifera (N = 43), and the only individual of Chrysemys picta were positive for salmonellae. These percentages of detection of salmonellae in turtles were independent of the location of the sampling in the Rio Grande, the species and the gender of the turtles. Although individuals of captive turtles testing positive for salmonellae were generally positive for all body parts tested (i.e., the cloacae, the carapace, the ventral base of the left rear leg, underneath one or more of the claws on the front feet, and the ventral base of the tail), individuals of free-ranging turtles testing positive for salmonellae were often positive for only one or two body parts. Our results demonstrate that salmonellae are prevalent in high rates in both captive and free-ranging turtles.

The breeding biology of Ranitomeya biolat was studied in lowland rain forest dominated by patches of bamboo in the Tambopata region of Peru. A grid of cut lengths of bamboo was sampled 21 times over a six-month period, and the presence of R. biolat adults, tadpoles, and eggs was recorded. A total of 94 adult frogs was captured from bamboos on 271 occasions. Egg masses were deposited on the inside of bamboo stems, but 41% failed to produce any tadpoles. Tadpoles developed in water trapped within the internodal cavity and took 58 days from hatching to reach full metamorphosis. Tadpoles in bamboos with eggs grew significantly faster than tadpoles in bamboos without eggs, suggesting that oophagy may be occurring. The use of bamboo as a specialist breeding niche by R. biolat is dependent on the bamboo interior being exposed by other organisms.

In this study, we determined how well the snout–vent length (SVL) of anurans estimated their mass for 36 species in the New World. Linear regressions of log-mass on log-SVL were highly significant for all species, explaining more than 75% of the mass variation in most species, and over 50% of the mass variation in all species. We also investigated differences in the mass/SVL relationship within species, comparing juveniles to adults, females to gravid females, and males to females, to determine the importance of developing separate regressions for sex or life-stage classes. Three of six tests between juveniles and adults, and two of nine tests between females and gravid females, indicated statistically significant differences, although these differences had only minor effects on mass estimates. More statistical differences in regression equations occurred between males and females; again, these differences were unimportant for estimates of mass in some cases, but they were important where there was strong sexual size dimorphism within a species. Continued collection of both SVL and mass data in new field studies of anurans will provide broader analyses of mass/SVL regressions. These species regressions along with data on density can be used to determine anuran community biomass.

Microhabitat selection by reptiles can be affected by a complex interplay of abiotic and biotic factors. The Brown Treesnake (Boiga irregularis) is an efficient nocturnal predator that hunts in the tropical forest canopy and on the ground, using visual and chemical cues. To identify the factors influencing Brown Treesnake microhabitat use, we experimentally manipulated an abiotic factor, moonlight level, and a biotic factor, prey presence. We hypothesized that (1) moonlight would affect microhabitat use and (2) the presence of prey would alter microhabitat use in various moonlight levels. Trials were conducted in a large laboratory chamber with artificial trees in simulated new, half, and full moonlight. In each trial, the snake's location in canopy, subcanopy, or open ground was recorded at 60-sec intervals for 100 min. Treesnake microhabitat use was determined in three moonlight levels without prey present and in two moonlight levels with a mouse (adult Mus musculus) or a Mangrove Monitor (juvenile Varanus indicus) present. The treesnakes used open ground areas more as moonlight decreased, and they used the canopy more as moonlight increased. No significant differences existed within a moonlight level between trials with or without prey. Thus, moonlight appeared to supercede prey availability in affecting Brown Treesnake microhabitat use. Additionally, the effect of nocturnal illumination on Brown Treesnake habitat use may also have important conservation implications regarding trapping techniques and deterring the snakes from specific areas.

We describe a new species of Anolis from a high-elevation locality in the Department of Cusco, Peru. This species is similar to Anolis boettgeri but differs in characters of scalation and coloration. We reanalyze Anolis albimaculatus and find this species to be a synonym of A. boettgeri. We describe variation in A. boettgeri based on topotypical material, including the first described males of the species. Phylogenetic analysis of the new form places it within the Dactyloa/latifrons clade of South American “Alpha” Anolis.

Previous laboratory studies of the Brown Anole, Anolis sagrei, have shown that males distinguish between familiar female cage mates and unfamiliar females in mating tests and preferentially mate with unfamiliar females. The purpose of this study was to test the hypothesis that males distinguish between former female residents of their territories and unfamiliar, nonresident females as preferred mating partners. To test the hypothesis, a total of 36 pairs of reproductively active males and females were captured from a natural habitat in the Miami, Florida area. For half of the pairs, a male and a female resident of the male's territory were captured, and for the other half, a male and a nonresident female unfamiliar to the male were captured. Within five hours of capture, the male and female of each pair were placed into a test cage in the laboratory and videotaped for one hour. Males paired with unfamiliar, nonresident females copulated significantly more frequently than males paired with former female residents of their territories. Moreover, the proportion of males that copulated was significantly greater in males that were paired with unfamiliar females than in males that were paired with resident females. These results support the hypothesis that male A. sagrei distinguish between former female residents of their territories and unfamiliar, nonresident females as preferred mating partners and suggest that free-living males might exhibit a mating preference for unfamiliar females over female residents of their territories.

The characteristics of snake populations are reportedly difficult to quantify and such information exists for relatively few species, including Bullsnakes (Pituophis catenifer sayi). A Bullsnake population in southwestern Wisconsin was surveyed for three seasons (2003–05). All snakes encountered were (1) implanted with Passive Integrated Transponders for mark-recapture analyses of population size, (2) aged by size, and (3) sexed via probing and released. A subset of individuals was also implanted with radio transmitters to determine, in part, mortality rates and sources. Although recapture rates over the three years of surveying were low, an unbiased Lincoln-Petersen estimation was possible. This estimation revealed a small adult population size (N = 28.8) that was similar to the total number of adults encountered throughout the study (N = 30). Chi-squared analysis revealed that adult sex ratios were similar to 50 : 50 in all years. Mortality rates were high, particularly in females (44%), and sources of mortality were identified as predators and anthropogenic causes.

In most Anuran species, space use includes a lek mating system with defense of a calling site for only a short time period during an individual's lifespan. In contrast, territoriality over a longer time period by one or both of the sexes has been reported in all studied dendrobatid frogs. In most dendrobatid species, territories are defended for reproductive purposes, and typically, males vocalize from these territories to attract mates and repel rivals. It has been hypothesized that reproductive resources such as oviposition sites or tadpole deposition sites are defended. For reproductive resource defense to occur, reproductive units (eggs or tadpoles) must be deposited at sites where the territorial individual displays agonistic interaction with intruding individuals. Here, we challenge this assumption in a field study on the poison frog Dendrobates ventrimaculatus in French Guiana. We show that home-range size is affected by spatial distribution of bromeliads. Clutches of eggs were found to be predominantly deposited in bromeliads located inside the 50% Kernel core areas of activity within male territories, although tadpoles were deposited more frequently outside these core areas. Vocalization of males only occurred in agonistic interactions with other males or while courting a female. Our data show that (1) males of D. ventrimaculatus defend small territories containing their reproductive resources, (2) these resources are not limited in number, and (3) territories are not defended for characteristics supporting advertisement vocalization. We conclude that males defend territories to increase the success of courting a female without interruption by other males.

Snakes have very different ecologies and habits from other non-ophidian squamates (“lizards”); yet ecological data from sympatric populations of lizards are often used as models to explain resource partitioning in sympatric groups of all squamates. Most snake assemblages show greatest ecological divergence in use of dietary resources. We use dietary, spatial, and reproductive data in a clade of five sympatric snake species with similar ecologies to test previous assumptions of how snakes partition resources in a species-rich community. Species show dietary specializations, with species of Simoselaps and Brachyurophis fasciolatus feeding exclusively on lizards and Brachyurophis semifasciatus eating only squamate eggs. Some species show trends regarding differential habitat use; Simoselaps bertholdi and B. semifasciatus are habitat generalists, whereas the other species are not captured in flat areas between sand ridges. Time of peak activity is not partitioned seasonally because all species, except B. fasciolatus, are most active in December. Partitioning of dietary resources is a stronger structuring agent than is partitioning of habitat resources in this community as indicated by the amount of resource overlap. Diet is the most important dimension in explaining ecological divergence among these elapid species, in agreement with prior studies of resource partitioning in snake assemblages.

A helodermatid dentary and osteoderms from the Miocene Thomas Farm locality in Gilchrist County, Florida, demonstrate the broad historical distribution of Helodermatidae in North America during the Tertiary. A comparative approach, taking into account variation in extant Heloderma, reveals that the dentary is intermediate in several characters between the plesiomorphically long, low, mediolaterally narrow dentary of Eurheloderma gallicum and the taller, wider dentary of extant Heloderma. An eminence upon the intramandibular septum in the Thomas Farm helodermatid and some extant Varanoidea is part of a previously unrecognized anatomical structure, a foramen formed by dentary and postdentary elements and normally covered by the splenial. The teeth of the Florida helodermatid are intermediate between the more numerous, shorter teeth of E. gallicum and the fewer, taller teeth of extant Heloderma. Certain dental structures whose evolution is here elucidated are part of the novel helodermatid venom delivery system. The evolution of the dentary and teeth in Varanoidea as a whole is a more complex and informative story than was previously appreciated. No living varanoid displays unmodified the primitive varanoid conical tooth morphology. Extant Heloderma show a dentition modified in association with venom delivery, whereas Varanidae show labiolingual compression of the tooth crown. Varanus in particular is highly modified and should not be used as a proxy for the varanoid ancestor in studies of the dentigerous elements and dentition. The informativeness of isolated squamate dentaries is evidenced by the derivation of 15 new phylogenetic characters from the anatomy of helodermatid dentaries and dentition.

The phylogenetic placement of the limbless lizard genus Anelytropsis within Squamata was investigated using partial mitochondrial 16S rRNA sequences (422 bp). A total of 30 species, representing most of the major currently recognized squamate clades, was included in the analysis. As in previous morphological studies, Anelytropsis was strongly supported in Bayesian (mixture and unpartitioned models) and maximum-likelihood analyses as the sister taxon of Dibamus. Thus, a monophyletic Dibamidae composed of these two genera is supported by molecular data for the first time. Furthermore, several relationships in the inferred tree, although weakly supported, were congruent with those found in previous molecular phylogenetic analyses. Among these, Gekkota and the Dibamidae were recovered as relatively basal groups within Squamata. A nonmonophyletic Scleroglossa and Lacertiformes (= Amphisbaenia Lacertidae Teiidae Gymnophthalmidae) also were recovered. Although only weakly supported, a major difference from other recent molecular studies is the basal position of Serpentes.

We compared shell temperatures of Painted Turtles (Chrysemys picta) overwintering in two different ponds in Algonquin Park, Canada, over one winter. Movements under the ice occurred from late November into late December or early January, and based on thermal data, turtles were likely not buried in the substrate. Over the course of the winter, one pond became severely hypoxic, whereas the other remained more highly oxygenated. Turtles in the hypoxic pond exhibited significantly lower shell temperatures than did the turtles in the normoxic environment, despite significantly cooler average water temperatures in the normoxic pond. Painted Turtles submerged in normoxic water can assimilate O₂ through extrapulmonary means, and cutaneous O₂ uptake at low temperatures would significantly delay the onset of metabolic acidosis. Therefore, we suggest that, in the present study, turtles in the hypoxic environment likely could not assimilate O₂ cutaneously; thus, these individuals may have voluntarily selected low temperatures to delay metabolic acidosis and conserve energy stores for the active season. Our limited data suggest that Painted Turtles possess behavioral adaptations to detect and respond to aquatic hypoxia.

We tested a common prediction of the thermal coadaptation hypothesis in the Northern Map Turtle (Graptemys geographica), an aquatic emydid with pronounced aerial basking. We measured the effect of body temperature on two locomotor performances (swimming and righting) to determine optimal temperature of performance (T_o) for each trait. According to the thermal coadaptation hypothesis, the preferred body temperature range (T_set) of ectotherms should match T_o of thermally sensitive traits that influence fitness. However, we predicted that preferred basking temperature and locomotor performance of Northern Map Turtles would not be coadapted, given that basking occurs on land and locomotion in water. We also tested for an ontogenetic shift in performance curves. We found that adult Northern Map Turtles have a wide T_set (19–30°C), both hatchlings and adults can achieve near-maximum performance over a wide range of temperatures, and an ontogenetic shift is present for swimming but not for righting. Although T_o for the two locomotor performances of adult turtles were within T_set, the large range of T_set coupled with the wide breadth in locomotor performance makes falsifying or supporting the coadaptation hypothesis difficult for these traits in Northern Map Turtles. Other metabolic and physiological processes need to be considered to understand more fully thermal coadaptation in aquatic emydids.

We studied litter size, size at birth, and relative litter mass (RLM) in two populations of the crevice-dwelling lizard Xenosaurus platyceps: one located in a low-altitude tropical forest; and the other in a high-altitude temperate oak forest. We found a significant relationship between female size and litter size. Females from the temperate site produced significantly larger litters in comparison with those from the tropical site after adjusting for female size. Neither a relationship between female size and offspring size nor a difference between populations in offspring size was detected, which suggests that this trait could be either constrained or optimized. RLM showed the same pattern as litter size: Larger females exhibited greater RLM, and this trait showed significantly larger values in the temperate locality. This pattern is explained by evidence that females in the temperate population are producing more young of similar size than those produced by their tropical counterparts. We did not find significant interannual variation in any of the reproductive traits studied. We suggest reciprocal transplant or common garden experiments to determine the genetic and proximal causes of the observed intraspecific variation.

We investigated habitat selection and movement patterns of female Grass Snakes (Natrix natrix helvetica) in an agricultural landscape where cropping is the dominant farming practice. The aims were to estimate the relative importance of monoculture as habitat for these snakes and to assess its functional relevance to the snakes. Radiotelemetry was used to measure movements by snakes, and the locations of animals were used as sampling points to examine patterns of habitat use. In the course of the tracking period, all females used monocultures. Because of a combination of suitable basking sites, favorable foraging opportunities, and low pressure from avian predators, monocultures may provide at least temporary advantages over more natural habitats, with a seasonal shift in functional relevance induced by the time of oviposition. Overall, the snakes showed a marked preference for edge habitats, which make up only 7% of the study area. At the microhabitat level, a snakes' probability of occurrence was positively correlated with either percentage cover of perennial layer or distance to cereal crop or with both. Our results clearly demonstrate that monocultures are a component of the habitat of female Grass Snakes during their summer activity period in the study area. However, the marked preference for edge habitats, and the response to particular microhabitat features, emphasizes the importance of a mosaic of habitats and structural heterogeneity of edge habitats for the conservation of this snake population.

Ground coloration is highly variable in many reptile species. In turtles, ground color may correspond well to the background coloration of the environment and can change over time to match new surroundings in the laboratory. Variable carapace and plastron coloration across three habitat types were investigated in the Black Softshell Turtle, Apalone spinifera atra, by measuring individual components of the RGB (Red, Green, Blue) color system. In general, A. s. atra carapaces were darker in turtles from lagoons than in turtles from playa lakes. Red and green values were significantly different among all pairs of habitat types, but blue values differed only between the playa lakes and lagoons. Mean color components (RG only) for each population were significantly correlated with corresponding values for the bottom substrate, indicating a positive association of carapace and habitat substrate color components. In contrast, plastron ground color RGB channels showed no significant differences between habitat types and no significant correlations with substrate RGB. These results suggest that dorsal background matching in A. s. atra may be responsible for some of the variation in this key taxonomic trait.

Crocodilians communicate with each other using stereotyped acoustic and visual signals that convey reproductive, territorial, and other information. I mapped 14 such behavioral characters onto a phylogeny of seven crocodilian species to determine behavioral homologies, under the assumption that such behaviors are heritable. The results indicate that the following are ancestral behaviors for Alligatoridae Crocodylidae and, therefore, were present by the Late Cretaceous: intraegg vocalization; juvenile distress calls; circling during courtship; head-emergent tail-arched posture; snout lifting; head slapping; inflated posture; narial geysering; bubbling; mutual snout-rubbing; and rubbing the snout on the dorsal surface of an intended mate. Ancestral (Late Cretaceous) courtship behaviors of the clade included circling, narial geysering, bubbling, mutual snout rubbing, and rubbing the snout on the dorsal surface of the intended mate. The headslap-roar is an ancestral advertisement display for the clade represented by Crocodylus acutus, Crocodylus moreletii, and Crocodylus intermedius and was present by the Pliocene. The behavior of many crocodilian species has been little studied, and it is possible that the picture presented here will change with the addition of data from more crocodilian species.

The analysis of stomach contents can shed light on patterns of prey availability and foraging habits of a predator; however, recent studies have shown the potential bias in dietary studies resulting from differential digestion rates of various prey items. The stomachs of 286 Nile Crocodiles (17–166 cm snout–vent length) were lavaged over a two-year period. Taking prey residence times into account, the contents were examined for prey eaten within 24 h. Crocodylus niloticus has a similar ontogenetic shift in diet to that of other crocodilians. Yearlings consumed primarily aquatic insecta and arachnida. As crocodile size increased (juveniles), the diet became more diverse including crustacea, amphibia, and fish. The largest size class (subadults) consumed primarily fish. Yearlings fed consistently throughout the year; however a higher proportion of empty stomachs occurred within the juvenile and subadult size classes during the winter months. Seven species of nematodes were found within the stomachs, four of which represent new geographic records.

The use of fluctuating asymmetry (FA) as a measure of developmental instability, and its relationship to stress and fitness, is highly controversial. Here, we present results from a preliminary study comparing levels of asymmetry in various characteristics between two island populations of the Italian Wall Lizard (Podarcis sicula), one of which was recently founded. We relate individual asymmetry to several measures of physiological performance. Levels of FA varied clearly among the traits studied. Repeatability of FA estimates was high for meristic traits but low for metric traits. Levels of FA were on average higher in the newly founded population. We found a significant decrease in exertion (time until exhaustion by continuously chasing) with increasing levels of fluctuating asymmetry (i.e., more symmetric individuals had a higher exertion). Speed of locomotion showed a positive trend with increasing FA. No relationship was found between individual levels of FA and bite force. These results suggest that FA estimates, based on the accurate measurement of several traits, may be useful in explaining differences in developmental stability and physiological performance at the individual and population level.

Wetlands are essential breeding sites for many amphibians. The importance of terrestrial habitat for many aquatic-breeding amphibian species is well known, although often understudied and understated. This study examined the recapture rates, habitat use, and site fidelity of Cope's Gray Treefrogs (Hyla chrysoscelis) within and surrounding a wetland for 15 months. Using visible implant elastomer and visible implant alpha tags, we tracked individuals as they used a grid of 110 PVC pipes as refugia. PVC pipe refugia allow treefrogs to be sampled when not actively calling or breeding. We captured 82 individual frogs a total of 141 times (59 recaptures). Treefrogs occupied pipes every month except during winter (December, January, and February). Recapture rates decreased during the breeding season (May, June, and July). Preferred pipes were in terrestrial habitat or close to trees instead of in aquatic habitat devoid of trees. Treefrogs displayed high site fidelity; only three frogs were recaptured in pipes different from those in which they were originally captured. Our results suggest that H. chrysoscelis select terrestrial habitat adjacent to wetlands and have high site fidelity, which could have important implications for the conservation of treefrogs and other wetland-breeding amphibians.

Two new species of the genus Phyllodactylus are described based on material collected in the southern portion of Departamento de Amazonas, Peru. Both species are well differentiated from all other South American Phyllodactylus based on characteristics of their morphology. In the case of one species, its large adult size and lack of well-defined rows of strongly keeled scales differentiate it from other Phyllodactylus, whereas in the second species, the presence of an enlarged postanal scale is diagnostic. Both species were collected in the xeric Balsas region of the upper Marañon Valley, and exhibit some similarities to other assemblages of sympatric Phyllodactylus in South America. The Balsas region is an area of endemism that warrants further attention from systematists and conservation biologists.

Conservation of pond-breeding frogs requires information on movement patterns within populations. The Green and Golden Bell Frog (Litoria aurea) is endangered in New South Wales, Australia; yet little is known about its movement biology. To inform conservation planning and habitat restoration, we conducted a mark-recapture study to describe the movement patterns of adult L. aurea among permanent and ephemeral waterbodies, on Kooragang Island, New South Wales, Australia. Twenty-nine percent and 18% of 551 males and 228 females marked, respectively, were recaptured on ≥ 1 occasions over two breeding seasons (2000 and 2001). Most recaptures were in the same permanent waterbody as the original capture (53% males, 65% females). Twenty-seven (24%) male and seven (50%) female movements were from a permanent waterbody to the nearest permanent waterbody (<50 m), respectively. Male L. aurea, usually large individuals, moved relatively long distances (>200 m) to ephemeral waterbodies from permanent waterbodies after prolonged heavy rain. Of the total number of male and female movements recorded, 44 (39%) and two (14%) were to or from ephemeral waterbodies, respectively. Our results demonstrated high site fidelity of L. aurea to individual waterbodies and groups of neighboring waterbodies, especially permanent ones. Our results showed that L. aurea tended to breed in more permanent waterbodies but reproduced opportunistically in ephemeral waterbodies where recruitment was less successful. Habitat restoration projects for L. aurea should construct permanent and ephemeral waterbodies and provide adequate buffer zones that protect the terrestrial habitat.

Tadpoles of Cope's Gray Treefrog, Hyla chrysoscelis, were reared in the presence of two concentrations of colloidal clay to evaluate the influence of clay-associated, organic materials on growth. There were no dose-dependent effects of the amount of clay, but total tadpole lengths were 14.1 and 12.1% larger than clear-water controls for low and high clay content treatments, respectively. Similarly, tadpole wet masses were 35.1 (low clay) and 38.5% (high clay) larger than controls. Organic molecules and small organisms are sequestered on the enormous, collective surface area of the negatively charged clay particles, and we attribute the increased growth performances to these potential food sources.

Sex-biased predation rates have been documented in marine turtles, but no study to date has addressed the causes of such bias. In Shark Bay, male Loggerhead Turtles (Caretta caretta) display evidence of Tiger Shark (Galeocerdo cuvier) attack more often than do females, and sex-specific differences in swim speed or maneuverability have been posited as a possible reason for this pattern. We used simulated shark attacks (boat chases) in shallow water to test this hypothesis. Differences in speed and maneuverability between males and females were not detected, indicating that the heightened vulnerability to predation of male Loggerhead Turtles in Shark Bay requires a different explanation.

The second-to-fourth digit ratio (2D : 4D) is a well-studied sexual dimorphism that likely arises as a result of prenatal androgenic effects on homeobox gene expression. This dimorphism has been found to exhibit interesting phylogenetic patterns in which females have larger ratios than males among most mammalian species and males have larger ratios than females in most avian and reptilian species. Digit ratio has not been measured in more basal taxa such as amphibians. In this study, 2D : 4D and snout–vent length (SVL) were measured in 40 male and 44 female adult Oophaga [=Dendrobates] pumilio frogs to investigate the existence and patterning of sexual dimorphism. The 2D : 4D of the rear feet varied significantly by sex with males having a larger ratio than females. The digit ratio of the front feet did not differ between the sexes. SVL or its interaction with sex did not affect 2D : 4D on any of the feet. These results indicate that 2D : 4D in an anuran is both sexually dimorphic and follows a pattern between the sexes similar to that of diapsid species. A potential application of 2D : 4D to environmental monitoring is also discussed.