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Historical records and recent studies indicate that populations of the Copperbellied Watersnake (Nerodia erythrogaster neglecta) are in decline. Reduction in range and fragmentation of populations are largely based on human activities, primarily through alteration of shallow wetlands. We conducted a comparative study of habitat use to determine why N. e neglecta may be more vulnerable to human-induced changes than sympatric congeners. Nerodia erythrogaster neglecta were observed primarily along shorelines with gentle slopes near very shallow water and often used herbaceous vegetation, logs, grasses, and sedges substrate categories. Nerodia sipedon pleuralis used habitat most similar to N. e. neglecta. Although N. s. pleuralis were observed to be more aquatic and were more often found in open water, they showed the same close association with shorelines and basking substrates as N. e. neglecta. Nerodia rhombifer is the least selective in habitat use of the three species and is the least similar in habitat use to N. e. neglecta in this study. As a whole, the results of this study support previous research that suggests N. e. neglecta is a seasonal habitat specialist. The extensive destruction of seasonal wetlands in the Midwest may thus have a greater impact on N. e. neglecta than their sympatric congeners.
Recently discovered snake fossils from the Pliocene (Blancan, approximately 2.85–2.95 MYBP) Taunton local fauna, Adams County, Washington, consist of eight genera and at least nine species representing one boid, seven colubrids, and one viperid. Two of the colubrids are extinct (Elaphe pliocenica and a new genus and species). Tauntonophis morganorum is described as a new genus and species. Biogeographically the Taunton snake assemblage is most similar taxonomically to the Recent snake fauna from the Klamath Mountains Province of southwestern Oregon. From a paleoclimatic stand point, the Taunton snakes suggest that this area of the Columbia Basin had a milder, moister climate approximately 2.85–2.95 MYBP.
Like many Neotropical frogs, a number in the genus Eleutherodactylus have declined or gone extinct in the past two decades. However, the extent of Eleutherodactylus population declines is unknown. Our objective was to identify a good method for monitoring the density of Eleutherodactylus populations to assess the extent of declines. We did this in two ways. First, we compared two methods of directly estimating density, closed population capture-recapture analysis and distance sampling, and one method of indirectly estimating density, visual encounter surveys, for multiple Eleutherodactylus species at three sites in Ecuador. We then conducted a power analysis to estimate the power of our current sampling design to detect declines. Distance sampling estimates of density were biased low compared to capture-recapture estimates. When we corrected this bias, distance sampling estimates became imprecise. Estimates of density from visual encounter surveys were also imprecise. In contrast, capture-recapture estimates were fairly precise and most likely unbiased. Moreover, capture-recapture analysis had the most power to detect declines, although even with capture-recapture analysis, power was low with only five years of sampling. We conclude that capture-recapture analysis is a good method for monitoring Eleutherodactylus density over time, but the sampling area and/or the number of sampling occasions should be increased from the area and number of occasions used here in order to increase sample sizes and therefore power.
Habitat destruction and fragmentation are often cited as primary causes for declines in reptile and amphibian populations. Smaller habitat patches constrain population size resulting in increased extinction risk caused by stochastic processes. However, patch size also may affect populations in a deterministic manner. We used mark and recapture techniques to examine effects of patch size on demographics of the Florida Scrub Lizard (Sceloporus woodi). We examined populations in eight scrub habitat patches that differed in size but were similar with respect to other habitat characteristics. Abundance, survivorship, and recruitment were positively associated with patch size for both sexes. Individual growth rate increased with patch size for males but was negatively associated with patch size for females. Although our data indicate that patch size strongly affects demographics of scrub lizards, mechanisms responsible for these patterns are unknown. We discuss conservation implications of area-sensitive demography for local and regional populations. In particular, we suggest caution when constructing metapopulation models that assume homogenous survival and fecundity rates for all patches regardless of patch size.
Many members of the Iguania group of lizards engage in stereotyped and species-specific “pushup” or “headbob” displays. Temporal attributes of displays have been quantified for a number of species in the genus Anolis, but few of these studies have examined effects on display structure of signaler sex, display context, and population. With this goal in mind we conducted a comparative study of three Anolis species permanently established (“naturalized”) on the island of Bermuda: Anolis grahami from Jamaica, Anolis extremus from Barbados, and Anolis leachi from Antigua and Barbuda. These anoles are distantly related to each other and to Anolis carolinensis—the only Anolis species for which all of the above influences on display structure have been examined in detail. Adults were field-captured and transported to the laboratory where paired interactions were videotaped and headbob displays analyzed. Results revealed one or more variables to exhibit sexual dimorphism in each species, and display context had little influence on signal structure. We then compared results from our founder populations on Bermuda with those published for two of our study species' source populations. No significant differences in headbob display units were found between A. grahami on Bermuda and on Jamaica. In contrast, male A. extremus on Bermuda produced fewer units per display than did males from Barbados, although the nature of the published data prevented statistical comparison.
We studied the ecology of Anolis punctatus and Anolis transversalis at six localities in the Amazon region of Ecuador and Brazil from 1994–1999. Both lizards are arboreal, about the same size (A. punctatus slightly larger) but differ in some body proportions. Anolis transversalis is restricted to undisturbed primary forest more so than A. punctatus, but both use similar microhabitats. During midday, A. transversalis was not observed, suggesting that individuals may not be active near the ground at that time. Both species are thermal conformers although each was able to maintain Tb slightly higher than that of its perch. Most lizards contained prey, and, overall, a positive relationship existed between lizard body size (SVL) and mean prey volume. Volumetrically, A. punctatus ate mostly ants and orthopterans, whereas A. transversalis ate mostly roaches, beetles, and ants. Dietary overlaps were low (0.56). These two species can be considered “crown giants” among Amazonian anoles. Similar to many Amazonian rain-forest lizards, ecological traits of A. punctatus and A. transversalis render them likely candidates for local extinction when deforestation occurs.
Intraspecific variation in acoustic signals may reflect local variation in the intensity of natural and sexual selection and random drift. We examined intraspecific variation in the advertisement call of Spicospina flammocaerulea, a southwestern Australian frog species with a limited distribution, fragmented range, small population sizes, and specific breeding habitat requirements. Of the six populations examined, one in particular differed significantly in dominant frequency and body size. There was no relationship between among-population geographic distance and among-population divergence in call structure suggesting that the divergence is not caused by random drift. A correlation analysis detected a positive relationship between the size of males and females found in amplexus. However, there was no evidence of mated males differing in size from unmated males indicating that the differences in dominant frequency are unrelated sexual selection. Call structure variation may reflect differences in recruitment and resultant age structure of local populations.
From 1997–1999 we studied one of four known populations of Oregon Spotted Frogs (Rana pretiosa) in Washington State to investigate patterns of range use, movements, and habitat selection. Sixty telemetered frogs occupied a range that was a mosaic of wetlands (15.6 ha) and upland pasture (13.2 ha) grazed by dairy cows. Mean (± SE) home-range size for four frogs was 2.2 ± 1.0 ha. Patterns of spatial use, determined from 654 telemetry locations, were closely related to season and changing surface water conditions. During the breeding season (February to May), frogs occupied ≥50% of the area they used the entire year, and oviposited in shallow pools (depth = 16.9 ± 0.6 cm) on the margins of an ephemeral creek. In the dry season (June to August), frogs moved down stream to deeper, permanent pools (depth = 23.6 ± 1.0 cm), significantly reduced their movements, and occupied the smallest ranges of any season. During the wet season (September to January), frogs moved back up stream and reoccupied the breeding range. During the coldest weather, frogs buried themselves at the base of dense vegetation in shallow water under ice (depth = 17.4 ± 0.8 cm). Frogs avoided dry uplands. Frogs selected sedge (Carex obnupta, and Carex utriculata)/rush (Juncus effusus) habitat during breeding and hardhack (Spiraea douglasii) cover during the dry season that shaded and maintained remnant pools. Frogs preferred microhabitats with 50–75% water surface exposure based on comparisons between telemetry locations and nearby locations that were randomly selected. Aquatic requirements necessary to complete the life cycle of Oregon Spotted Frogs in this population include (1) stable, shallow water areas for egg and tadpole survival in the breeding season, (2) deep, moderately vegetated pools for adult and juvenile survival in the dry season, and (3) shallow water levels over emergent vegetation for protecting all age classes during cold weather in the wet season.
The effect of seed ingestion by two species of iguana (Iguana iguana and Ctenosaura pectinata) on germination and on seed damage by insects was investigated in a Mexican tropical dry forest. We fed individuals of I. iguana with fruits from 11 plant species. Thereafter, we collected the feces, and seeds were removed and sowed. To assess whether seed damage by insects is affected by iguana ingestion, we removed and sowed the seeds of the legume tree Prosopis juliflora contained in feces of C. pectinata. Individuals of I. iguana consumed four of 11 plant species (Cordia alba, Momordica charantia, Pithecellobium dulce, and Lycopersicon esculentum). Overall, germination rate was significantly higher for ingested seeds than for control seeds, except for M. charantia, where no seed germinated. The proportion of P. juliflora seeds with bruchid damage was significantly lower for seeds ingested by C. pectinata (33%) than for control seeds (95%). The results suggest that Green Iguanas (I. iguana) are selective in their diets and that seed ingestion by both species of iguanas affected seed survival, germination rate, and dispersal but that their effects are species dependent. Iguanas might play a significant role in the reproductive strategies of some tropical plants.
Egg retention beyond the normal time of oviposition occurs frequently in oviparous squamate reptiles and is thought to be a response to unfavorable nesting conditions. During studies of the Eastern Fence Lizard (Sceloporus undulatus), we obtained data on the effects of extended egg retention on embryonic development, hatchling phenotypes, and posthatching survival under natural field conditions. Females that retained eggs beyond the normal time of oviposition produced heavier eggs with embryos more advanced (by one stage unit) at the time of oviposition than females that did not retain eggs for extended periods. Egg retention did not affect any hatchling phenotype (i.e., body size, thermal preference, running speed, desiccation rate, growth rate) but had a significant positive effect on posthatching survival in the field. However, the mechanism by which extended egg retention affects posthatching survival remains unclear. Our results have implications for the evolution of viviparity, but carefully designed experiments are needed to further understand the causes and consequences of extended egg retention.
We investigated reproductive and hatchling ecology of Gopher Tortoises at Camp Shelby Training Site in southern Mississippi from 1997–2000. Data were collected on nesting, hatching success, hatchling survivorship, and hatchling movements. Nests were deposited between 19 May and 17 July, with a peak of nesting activity between 26 May and 8 June. Mean clutch size was 4.8; mean nest depth was 16 cm; mean distance of nests from a burrow mouth was 46 cm; and eggs in most nests were laid in one or two horizontal planes. Eggs hatched in an average of 88 days. Mean hatching success was 28.8%. We found no significant differences in hatching success, incubation time, and hatchling carapace length and mass, between ruderal and forested sites. Forty-eight hatchlings were radio-tracked to determine survivorship and activity patterns. Hatchlings were tracked for up to 736 days; however, most hatchlings (65%) were killed within 30 days of hatching. Survivorship of hatchlings was low, with only one hatchling still alive at day 736. Most mortality was attributed to mammals (54%), although predation by red imported fire ants (Solenopsis invicta) was considerable (27%). Hatchlings that survived through their first overwintering period moved further from their nest sites than previously reported. Overall the tortoise poputlation had low recruitment rates, which likely influences demography at Camp Shelby.
A number of undescribed species of the iguanian lizard genus Liolaemus, formerly referred to Liolaemus rothi and Liolaemus boulengeri, have been identified in the northern Patagonian region of Argentina. Descriptions of two of the species are presented, along with their distributions and natural history. Liolaemus rothi is redescribed, a lectotype is designated, its likely provenience is discussed, and its distribution and natural history are given.
I used radio-telemetry to study home-range size and the impact of seasonal and daily temperature and weather patterns on activity and movements (May to August 1999 and 2000) in a population of Chrysemys picta marginata living in a small marsh system on Beaver Island, Michigan. Male and female home ranges were similar in size. Within the home range, most individuals favored one or two core areas. Total daily distance moved (based on three daily radio-locations per individual) averaged 68.1 m/day and was significantly different between years (1999: x̄ = 102 m/day−1 vs. 2000: x̄ = 39 m/day) but was not affected by gender or daily variations in water temperature or weather conditions during the summer months. Twenty-four-hour monitoring of individuals revealed that most turtles showed both diurnal and nocturnal activity. Home-range size averaged 1.2 ha and was larger in 1999 (x̄ = 1.8 ha, N = 7) than in 2000 (x̄ = 0.7 ha, N = 8). Annual differences in total daily distance moved and in home-range size probably occurred because the marsh was relatively small in 2000 because of low precipitation in that year. Terrestrial activity and multiple activity centers were observed mainly in males in 2000 and probably represented attempts by individuals to escape the crowded conditions of the Main Marsh area as its surface area decreased throughout the summer.
Although rare, some anurans show multimale spawning. Herein we present data on testes mass relative to body mass for 11 leptodactylids and report multimale spawning in Leptodactylus chaquensis and Leptodactylus podicipinus. Testes mass averaged 4.13% of body mass for L. chaquensis and 0.75% for L. podicipinus. Testes size of both leptodactylid species with multimale spawning show that they are large and close to values recorded for rhacophorid frogs with multimale breeding (0.71–7.79%). Large testes size in frogs with multimale spawning supports the sperm competition hypothesis.
We examined effects of body size and temperature on swimming performance in juvenile estuarine crocodiles, Crocodylus porosus, over the size range of 30–110 cm total body length. Swimming performance, expressed as maximum sustainable swimming speed, was measured in a temperature- and flow-controlled swimming flume. Absolute sustainable swimming speed increased with body length, but length-specific swimming performance decreased as body length increased. Sustained swimming speed increased with temperature between 15°C and 23°C, remained constant between 23° and 33°C, and decreased as temperature rose above 33°C. Q10-values of swimming speed were 2.60 (± 0.091 SE) between 18°C and 23°C, and there were no differences in Q10 between crocodiles of different sizes. The broad plateau of thermal independence in swimming speed observed in C. porosus may be of adaptive significance by allowing dispersal of juvenile animals at suboptimal body temperatures.
Karyotypes from the New Zealand skinks Oligosoma nigriplantare nigriplantare, Oligosoma nigriplantare polychroma, and Oligosoma microlepis are presented. All have a chromosome complement of 30, and there are no sex-related heteromorphisms. Comparisons with the other New Zealand skink genus, Cyclodina, and the Mauritius skink Leiolopisma telfairi, indicate Oligosoma and Leiolopisma share a common karyotype and that the Cyclodina karyotype is derived from Oligosoma.
Chthonerpeton indistinctum is nontropical, and reports suggest a distinct breeding season, allowing the potential for estimation of reproductive success. A total of 67 juvenile (and four adult) C. indistinctum were captured over five visits to a site in Rio Grande do Sul, Brazil, during Winter 2001. All individuals were marked and released, and the seven juveniles recaptured allowed a Schnabel estimate of 161.0 (95% confidence limits 81.9–343.1), the first quantitive estimate of juvenile caecilian abundance. However, the large size range of juveniles caught suggests that growth rates of individuals are highly variable or that C. indistinctum does not have a distinct breeding period in this region.
Potential sexual dimorphism of several aspects of antipredatory behavior by the Keeled Earless Lizard (Holbrookia propinqua) was studied by simulating approach by a predator. Females stayed closer to cover suitable for use as refuges than males, but no sex differences were detected in the distance between predator and prey when escape was initiated, the distance fled, or the tendency to enter refuges. Despite the sex difference in distance to cover, the regressions of flight initiation distance and distance fled on distance to cover were monomorphic. The sexes fled similar mean distances even though females were closer to refuges because some lizards stopped short of refuges and others fled past them. No differences in antipredatory behavior were noted between bright and plain female color phases.
The Sonoran coast of Mexico is characterized by an abrupt transition from marine bay to inland desert. We surveyed lizard species along 141 transects in desert shrubland, desert-dune scrub transitional, dune scrub, and sandy intertidal habitat areas within this transition zone. Cnemidophorus tigris, Uta stansburiana, and Callisaurus draconoides accounted for > 99% (N = 353) of individuals identified. Cnemidophorus tigris was almost entirely restricted to desert shrubland, U. stansburiana was mostly restricted to desert shrubland and desert-dune scrub transitional habitats, and C. draconoides was the most generalized in habitat use. It exhibited strong preferences for bare ground and was the only species observed in the sandy intertidal zone, an area devoid of vegetation. The intertidal zone had the highest lizard biomass of the four habitats but was completely dominated by a single species. Total lizard density and biomass were substantially less in desert shrubland, but lizard diversity was greatest in this structurally complex habitat. We suggest that habitat structure regulates lizard diversity, whereas food resources control lizard density across the transition zone.
We studied microhabitat use and selection by Northern Cricket Frogs (Acris crepitans) along a stream in west-central Missouri. Field observations of microhabitat use indicate that cricket frogs preferentially use moist (muddy) substrates with some proximity to shelter items (e.g., rocks) and the water. Laboratory choice experiments support the importance of substrate moisture and shelter presence. Temperature may also play a role in site selection independent of substrate selection.
Genetic divergence between two traditionally recognized subspecies, Liolaemus monticola chillanensis and Liolaemus monticola ssp., was assessed by allozymic comparison. Both morphotypes are syntopic and restricted to the mountains of the Cordillera de Chillán. Results of 17 presumptive loci have shown diagnostic alleles at five loci in Esterases and MDHP enzymatic systems. This provides evidence that both morphotypes show strong differences in their genetic structure, and they are independent lineages.
Few studies have systematically investigated the overwintering ecology of anurans. We used large-scale field enclosures to measure the winter densities of Wood Frogs (Rana sylvatica) in an upland deciduous forest adjacent to two breeding pools in eastern Massachusetts. Pitfall traps associated with one of our enclosure arrays were operated continuously from March to December 2000. Wood Frog densities ranged from 0–6.3 Wood Frogs/100 m2 (x̄ = 1.4, SD = 1.6, N = 17 enclosures) and declined as distance to the nearest breeding pond increased. The sex ratio of Wood Frogs wintering close (< 65 m) to the pond was more highly skewed toward males than the sex ratio of Wood Frogs wintering further from the pond (8:1 vs. 1.6:1). Adult Wood Frogs apparently only occupied this upland forest habitat during late fall and winter and did not use it during the summer active period. These results suggest that few wintering females may be protected within narrow regulatory buffers adjacent to breeding ponds and that the effects of habitat destruction on Wood Frog mortality may vary dramatically by season.
On the basis of degree of adaptation in tail autotomy, five lizard species studied on the same area in northeastern Kansas were arranged in a sequence of specialization. Eumeces obsoletus was the most specialized (hatchling tail conspicuously colored and behavior adapted to flaunt it); in Eumeces fasciatus also, the hatchling tail was conspicuously colored, but tail flaunting was less developed. In Cnemidophorus sexlineatus the hatchling tail was conspicuously colored but there was no tail flaunting. In Ophisaurus attenuatus, the tail was easily broken, but there was no special coloration or behavior to direct predator attack. In Crotaphytus collaris, the tail was neither conspicuous nor easily broken, and there was no regeneration.
Hawksbill Seaturtles have temperature-dependent sex determination. As such, the resulting sex ratios are of conservational and ecological significance. Buck Island Reef is an interesting location for sex ratio studies since it represents a natural and unexploited foraging ground for hawksbills in the Caribbean. To examine sex ratios, blood samples were obtained from juvenile Hawksbill Seaturtles captured on Buck Island Reef over a four-year period. We used a radioimmunoassay to determine testosterone levels in those samples and compared those values to testosterone levels of juvenile hawksbills from the Caribbean whose sex has been verified by laparoscopy. The results of this study reveal a significantly female-biased sex ratio (approximately 80% female) occurs in this juvenile aggregation inhabiting Buck Island Reef.
Dietary habits of the amphisbaenian Bipes biporus from the Baja California peninsula were examined based on analysis of stomach contents of over 200 museum specimens. Ants and termites were the most common prey items as measured by frequency, but a wide variety of other invertebrate prey items were noted. Many prey items were soft-bodied, but some hard-bodied invertebrates were consumed, and tooth marks on these hard-bodied prey items indicate that B. biporus may bite its prey as a means of capture or ingestion. Prey items varied widely in size but were always smaller in diameter than the gape of the B. biporus individual that had consumed them. Bipes biporus fits the pattern of a generalist predator that exploits prey items found both under the soil and on the soil surface covered by objects such as fallen bark or debris.
We analyzed relationships between presence and absence of seven amphibian species and characteristics of breeding ponds (physical, vegetation, substrate, spatial and surrounding habitat variables) at a protected montane area in Central Spain. We used classification trees for description and prediction of amphibian selection of breeding sites. Some factors identified in our models represent general preferences of the species, whereas others are consistent with demographic processes, including recent expansions and local declines of some species, that had been previously detected in the area. We discuss implications of a detailed knowledge of local habitat determinants for conservation.
We examined whether display behavior of territorial male lizards (Anolis sagrei) differed between locations within heavily used portions of their activity areas (cores), and locations outside of these heavily used regions. In a southern Florida hardwood hammock, we observed six males in each of four 20 × 20 m plots, recording each male's location and display behavior for three, 1-h sessions. When males were outside of their core activity areas, they produced more bobbing displays relative to nodding displays than when they were within their core areas. Similar relationships have been reported in other taxa, such as birds, but they have been little studied in reptiles. The causes and consequences of this display variation remain to be determined.
The active season of the Common Watersnake (Nerodia sipedon sipedon) in Missouri lasts about 170 days, from mid-April to early October. Females begin vitellogenesis in April, ovulate in June, and give birth in August to September. Reproduction occupies about 130 days (76%) of the active season. Food was present in 71% of vitellogenic snakes, 64% of pregnant snakes, and 43% of postpartum snakes. Coelomic fat mass decreased during vitellogenesis but increased during pregnancy. At parturition, 40% of females had sufficient fat reserves to reproduce the following year. Dry mass of ovulated ova/developing young did not change through pregnancy; however, wet mass increased from 45% in freshly ovulated ova to 78% at parturition. We conclude that reproductive females are not anorexic and that the increase in water content of the embryos adds considerable mass to the mother during pregnancy.
Tadpoles of many species develop enlarged tail fins in the presence of insect predators, but the function of this response is not known. Because large tails do not improve swimming performance, we tested the hypothesis that the tail attracts predator strikes away from the more vulnerable head and body region. We first confirmed the assumption that attacks to the tail are less dangerous: Living tadpoles escaped from dragonfly larvae only 10% of the time when the strike landed on the head and body but 29.4% of the time when struck on the tail. We then constructed model tadpoles having four tail shapes: normal, predator-induced, and 50% shallower and 50% deeper than normal. The models were presented to dragonflies and the location at which the insect's labium struck the model was noted. Models having the predator-induced tail sustained 16% fewer strikes to the head and body than did models with the noninduced tail, lending credibility to the hypothesis that the tail acts as a lure. Models with an unnaturally large tail were attacked more often on the body than was the predator-induced model, which may create stabilizing selection on tail shape.
To ascertain whether an ambush forager might select ambush posts bearing chemical cues, I presented emerald swifts (Sceloporus malachiticus) a choice between two ambush posts affording minimally overlapping views. One post was labeled with chemical cues from mealworms, the other was unlabeled. Occupancy of ambush posts was random with respect to mealworm scent. It appears that ambush foragers use chemical cues neither to locate and identify prey nor to select ambush posts.
Phylogeography of Hydromedusa maximiliani was assessed by sequencing a 416 bp fragment from the mtDNA control region. Based on this fragment, 18 haplotypes were detected among individuals from four populations throughout southeastern Brazil. Two major geographical groups could be distinguished, a western population represented by individuals from São Paulo state, and an eastern population, represented by individuals from Rio de Janeiro and Minas Gerais states. Divergence dates of 8–16 million years ago for eastern and western H. maximiliani populations fit orographical activities resulting in Serra do Mar and the Serra da Mantiqueira mountain uplifts during Pliocene and Miocene.
We studied seasonal variation in intersexual dietary overlap, perch use, and reproductive status of female Gonatodes humeralis in Eastern Brazilian Amazon. The diet of G. humeralis consisted primarily of invertebrates, and differed significantly between sexes in the rainy season, when there was also a significant intersexual difference in perch use (males perched higher). Reproductive activity was also more intense during the rainy season. Intersexual diet divergence may be a result of differential perch use, which appears related to intense reproductive activity in the rainy season. By using higher perches, males should increase their chance to find mates as suggested in other lizard species.
A six-year capture-recapture study allowed us to assess site-tenacity and spatial distribution of site-tenacious individuals in a population of the terrestrial, ovoviviparous Salamandra salamandra from Sintra-Cascais Natural Park, Portugal. The study area, an abandoned orchard, maintained large numbers of S. salamandra (about 400/ha). Most site-tenacious individuals were associated with tunnels in old stone walls that supported former agricultural terraces. Age was the only trait that explained site-tenacity in both sexes. The number of residents in each wall was positively related with wall length, and the sex-ratio of the residents was approximately 1:1 in every wall. Several animals spent all of the study period in the same area.
During the summer of 1997, 115 Plethodon metcalfi were collected on a 10-year-old clearcut (50) and in a nearby forest (65) in the vicinity of Highlands, North Carolina. Sex, reproductive status, snout–vent length, mass, and age were used to assess the effects of clearcutting. Relative to the forest population, the clearcut population had a smaller proportion of juveniles and proportionately fewer adult males in reproductive condition. Mature female salamanders had greater snout–vent lengths (SVL) than mature males, but there was no difference in average SVL between sites. Masses of mature salamanders did not differ by sex, but salamanders on the clearcut were more massive than their counterparts in forest. Ages of mature salamanders did not differ by sex or site. These results suggest that age distributions, masses, and reproductive efforts of P. metcalfi populations on clearcuts in the southern Blue Ridge Mountains are altered by clearcutting. Future research concerning effects of forest management on salamander populations must consider the possibility that, although salamanders may be entering managed areas shortly after cutting, these populations may be atypical in several important ways.
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