Intermittent, headwater streams recently have been recognized as important components of forest ecosystems and have been provided increased protection by the Northwest Forest Plan. However, few studies have examined their distribution, dynamics, and ecological roles, such as habitat for wildlife. My goal was to provide additional information on the ecology of intermittent streams in the Pacific Northwest. I examined and compared hydrologic, water quality, and physical characteristics of 16 intermittent streams in old-growth and young forest stands in the central Cascade Range in western Oregon. I documented amphibian communities and habitat associations in these streams during spring and summer. I used comparisons of current habitat conditions and amphibian communities between stand types to gain insight into potential impacts of timber harvesting on these stream systems. Of the streams surveyed in old-growth and young forest stands, relatively few (23%) were designated as intermittent based on my definition which included presence of a definable channel, evidence of annual scour and deposition, and lack of surface flow along at least 90% of the stream length. Intermittent streams in old-growth stands exhibited the following characteristics: (1) annual flow pattern in which streams started to dry in May and June and were mostly dry by July; (2) lengthy annual flow durations (range 6-11 months); (3) cool and stable daily stream temperatures; (4) primarily coarse substrates, such as cobbles and pebbles; (5) streamside vegetation comprised of predominantly coniferous overstories, and plant species associated with uplands or dry site conditions, such as Oregon-grape and salal, as well as riparian areas or wet site site conditions, such as Oregon-grape and salal, as well as riparian areas or wet site conditions, such as red alder, oxalis, red huckleberry, and vine maple (Steinblums et al. 1984, Bilby 1988); and (6) low to moderate densities of large wood, mostly moderately- and well-decayed. Study streams in young forest appeared to dry about one to two months later than the streams in old growth but had similar annual flow durations. They also were characterized by higher daily stream temperatures, similar diel fluctuations, finer substrates, more deciduous overstory and herbaceous understory cover, and lower densities of moderately-decayed large wood. Differences in habitat conditions between stand types may be attributed to timber harvesting as well as discrepancies in physiographic and geological factors, such as elevationgradient, and soil type. Amphibian communities in spring and summer were comprised primarily of the Cascade torrent salamander (Rhyacotriton cascadae), Dunn's salamander (Plethodon dunni), and Pacific giant salamander (Dicamptodon tenebrosus). Amphibian communities in streams in young forest stands exhibited different species composition and seasonal patterns in total density from those in old growth. Cascade torrent salamanders and Dunn's salamanders maintained similar densities and biomass between spring and summer by potentially adopting drought avoidance strategies. Species differed in their use of habitat types and associations with habitat features. In general, amphibian species were positively correlated with percent surface flow, water depth, intermediate-sized substrates and negatively associated with overstory canopy cover, elevation, and wood cover. Results of my study suggest that intermittent streams may warrant protection for their potential effects on downstream habitat and water quality and for their role as habitat for aquatic species, such as amphibians. Streamside vegetation should be maintained along intermittent channels to provide shade protection for water temperature regulation and sources of large woody debris and other allochthonous energy input, to help stabilize slopes, and to minimize erosion and sedimentation. At a minimum, intermittent stream channels should receive protection from physical disturbance during timber harvesting operations. However, since intermittent stream systems are highly variable, management should address individual site conditions and vary accordingly. / Graduation date: 1997

Thesis (M.S.)--North Carolina State University, 2003. / Title from PDF title page (viewed on Jan. 13, 2005). Includes vita. Includes bibliographical references (p. 76-86).

Environmental and anthropogenic stressors negatively affect amphibians in a variety of ways, often increasing their vulnerability to pathogen infection and mortality. Sampling for the pathogenic fungus Batrachochytrium dendrobatidis (Bd) was conducted in order to: 1) determine the presence of chytrid infection in stream-associated plethodontid salamanders of southeastern Kentucky, and 2) evaluate differences in infection intensity between salamanders residing in intact forest streams, timber-harvested streams, and surface-mined streams. During 14 sampling sessions occurring between March, April and May of 2013, DNA samples from 306 individual salamanders within 8 species from the family Plethodontidae were collected; additional amphibians (i.e. frogs, newts) were opportunistically sampled when encountered. Approximately 2.1% of the salamanders and 50% of the frogs sampled from intact streams, 2.3% of the salamanders and 80% of the frogs sampled from the harvested streams, and none of the salamanders and 100% of the frogs sampled from the mined streams tested positive for Bd. No significant differences in occurrence of Bd or infection intensity were detected between the treatment sites (x2 = 0.59; p-value = 0.75), or between individuals of a species between different treatments (see tables). These findings are the first to demonstrate that Batrachochytrium dendrobatidis is present in amphibians of eastern Kentucky.

Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains xiv, 258 p. : ill., maps. Includes abstract. Includes bibliographical references.

Theses (MS .)--Marshall University, 2005. / Title from document title page. Includes abstract. Document formatted into pages: contains vii, 66 p. including illustrations and map. Bibliography: p. 23-26.

Performance is an organism’s ability to accomplish a particular task or behavior, and morphology can have a major impact on the performance of an organism. Salamanders are ecologically diverse and can feed using a variety of behaviors depending on the environment in which feeding occurs. Feeding is accomplished through the use of the hyobranchial apparatus, which lies along the oropharynx, and this structure can have competing roles; in aquatic environments the apparatus is used for suction feeding and works to depress the floor of the mouth, but during terrestrial feeding this structure projects the tongue forward out of the mouth. Diverse morphologies of the hyobranchial apparatus enable varying degrees of feeding performance, both in aquatic and terrestrial environments. For my dissertation I have investigated the interactions, and possible functional trade-offs, of feeding morphology and performance in salamanders of Family Salamandridae. These salamanders are an ideal system for studying the interactions of morphology and performance across different environments because they have diverse ecology, being either fully aquatic, semi-aquatic, or terrestrial as adults, as well as differences in hyobranchial apparatus morphology. In these studies I have quantified the morphology and performance of seven salamandrid species feeding in aquatic (Chapter 2) and terrestrial (Chapter 3) environments to assess the links between these two parameters, as well as investigated the evolutionary patterns of feeding morphology, performance, and behavior across the Salamandridae (Chapter 4) to better understand the co-evolution of these traits across water-land transitions. During aquatic feeding salamanders use rapid mouth opening and hyobranchial depression to expand the oropharynx and generate negative pressure, and fluid flow, into the mouth. I hypothesized that more robust hyobranchial apparatus would yield increased aquatic feeding performance in salamandrids. When compared to semi-aquatic newts, the fully aquatic species, Paramesotriton labiatus, had greater mineralization of the hyobranchial apparatus, as well as relatively narrower basibranchial and wider ceratobranchial I + II complexes. These morphological differences coincide with greater aquatic feeding performance. Kinematics from high-speed videography revealed that maximum mouth opening velocities and accelerations were approximately two and five times greater, respectively, in Paramesotriton, and hyobranchial depression acceleration was found to be approximately three times greater than in the semi-aquatic species Pleurodeles, Notophthalmus, Triturus, and Cynops. Using digital particle image velocimetry, peak and average fluid velocities generated in Paramesotriton during suction feeding events were found to be 0.5 m s-1 and 0.2 m s-1, respectively, doubling that of all semi-aquatic species. These findings reveal that specialized morphology increases aquatic feeding performance in a fully aquatic newt. Salamanders use the hyobranchial apparatus and its associated musculature for tongue projection during terrestrial feeding. Hyobranchial apparatus composition and morphology vary across species and different morphologies are better suited for feeding in aquatic versus terrestrial environments. I hypothesized that differences in hyobranchial apparatus morphology and function result in functional trade-offs in feeding performance. Specifically I predicted that semi-aquatic and aquatic salamandrids with hyobranchial morphology suited for aquatic feeding would have lower performance, in terms of tongue-projection distance, velocity, acceleration and power, compared to terrestrial salamandrids when feeding in a terrestrial environment. I found that semi-aquatic and aquatic newts had lower tongue projection performance when compared to the terrestrial salamanders Chioglossa lusitanica and Salamandra salamandra. The fully aquatic newt, Paramesotriton labiatus, has a robust, heavily mineralized hyobranchial apparatus and was unable to project its tongue during terrestrial feeding, and instead exhibited suction-feeding movements better suited for aquatic feeding. Conversely, terrestrial species have gracile, cartilaginous hyobranchial apparatus and enlarged tongue pads that coincided with greater tongue-projection distance, velocity, acceleration, and power. Chioglossa exhibited extreme tongue-projection performance, similar to that seen in elastically projecting plethodontid salamanders; muscle-mass-specific power of tongue projection exceeded 2200 W kg-1, more than 350 times that of the next highest performer, Salamandra, which reached 6.3 W kg-1. These findings reveal that two fully terrestrial salamandrids have morphological specializations that yield greater tongue-projection performance compared to species that naturally feed in both aquatic and terrestrial environments. Salamanders of the Salamandridae that feed in both aquatic and terrestrial environments employ different behaviors depending on the environment. Using phylogenetic comparative methods, I assessed the relationships between feeding morphology, kinematics, and performance, and the ecology and feeding behavior of salamandrids. I also examined the co-evolution of feeding morphology and performance within Family Salamandridae. Behavior appears to co-evolve with feeding musculature, velocity of feeding movements, and fluid velocity produced during aquatic feeding. Flow velocity produced during aquatic feeding was related to the cross-sectional area of the rectus cervicis muscles, which rapidly depress the hyobranchial apparatus during suction feeding. Salamandrids with greater cross-sectional area of these depressor muscles generate faster flow velocity in aquatic feeding. Conversely, the evolution of hyobranchial apparatus morphology is more closely linked to ecology than to behavior. These findings indicate that both behavior and ecology are important for understanding the evolution of morphology and feeding performance across Family Salamandridae.

Advancements in molecular sequencing have revealed unexpected cryptic genetic diversity and contrasting evolutionary histories within genes and between genomes of many organisms; often in disagreement with recognized taxonomy. Incongruent patterns between the mitochondrial and nuclear evolutionary history can have several plausible explanations, but widespread systematic conflict inevitably challenges our conceptions of species boundaries when there is discordance between coevolving and coinherited genomes. It is unknown to what degree mitonuclear conflict drives the process of divergence, or how ubiquitous these patterns are across the tree of life. To understand the evolutionary relevance of intergenomic discordance we must identify the conflicting patterns that exist in natural systems by generating robust estimates of the underlying species history, quantify support for alternative hypotheses of lineage formation, and describe patterns of genetic variation present in robust nuclear genomic datasets. Empirically testing correlations between mitonuclear genomic conflict and reduced gene flow at the organism level will contribute toward a better understanding of lineage boundaries and how intergenomic interactions shape the process of divergence. Mitochondrial introgression has been inferred in many salamander systems with limited perspective from nuclear sequence data. Within dusky salamanders (Desmognathus), these patterns have been observed between morphologically and geographically disparate populations. I sequenced regions throughout the nuclear genome to reconstruct species trees, performed population-level analyses testing concordance between the mitochondrial, nuclear datasets, and nuclear genes with mitochondrial functions with the expectation that coevolutionary interactions among genomes are more likely to manifest in these regions. I also estimated migration rates between populations that may have experienced historical mitochondrial introgression to evaluate phylogeographic patterns. Using these data we definitively reject species models in which genetic boundaries are based solely on mitochondrial data, favoring geographic models instead. Furthermore, analyses soundly reject current taxonomic models based on morphological characteristics, suggesting there is greater lineage diversity than is currently recognized. I also used empirical assays of pre-zygotic reproductive mating behavior within and among populations containing diverse mitochondrial lineages to test metrics of reproductive isolation, and to determine if introgression shapes the evolution of complex traits directly influencing rates of divergence. These results may explain incongruent patterns observed between the mitochondrial and nuclear data as a function of inheritance and population dynamics rather than directly functioning to suppress nuclear gene flow. This research builds upon recent studies suggesting that speciation is a highly complex and often non-bifurcating process in which introgression can have a profound and lasting signature on the nuclear evolutionary history. Mechanisms responsible for divergence with gene flow challenge evolutionary biologists to reevaluate our notions and definitions of species boundaries to accommodate seemingly conflicted genomic patterns within and between genomes.

<div>Wetland-dwelling amphibians are of conservation interest for numerous reasons. They serve as biological indicators of water quality during their fully aquatic larval phase, and as carnivores that prey extensively on both terrestrial and aquatic invertebrates. These amphibians are an important link between terrestrial and aquatic food webs, and their wellbeing is an important factor when considering ecosystem health. Amphibians are facing global declines as their wetland habitats are being lost or degraded by human actions. There are efforts to restore wetland habitats, but it is far from certain which practices encourage amphibian occupancy.</div><div>I investigated which factors are important to the persistence of amphibians in restored and naturally formed wetlands to see if restored wetlands can accommodate similar species assemblages. Amphibians were surveyed over two years in a collection of 18 wetlands in Steuben and DeKalb counties, IN owned by The Nature Conservancy. Ambystomatid salamanders were surveyed using plastic minnow traps in springtime, and frogs were surveyed using call surveys in spring and summer. I used linear models to compare wetland plant dominance, wetland hydroperiod, restoration status, distance to nearest mature forest, adjacent forest age and basal area, and inter-wetland distance to amphibian species richness.</div><div>The species richness of Ambystoma salamanders was positively associated with larger wetlands, higher forest basal area, and central mudminnow presence; and negatively associated with older forests, distance to mature forests, and the presence of sunfishes. Ambystoma salamanders besides A. tigrinum were associated with ephemeral hydrology, naturally-formed wetlands, and a greater number of wetlands within one km; and negatively correlated with older forests.</div><div>Frog species richness was positively associated with larger wetland size, and negatively associated with seasonal wetlands, naturally-formed wetlands, distance to nearest mature forests, naturally formed wetlands, treatment for invasive plants, and number of other wetlands within 500m. Total amphibian species richness models did not perform well, but showed a preference for semi-permanent wetlands, smaller distance to mature forests, greater forest basal area, and greater distance between wetlands; and a preference against Scrub Shrub/Forest wetlands. Hylid frogs were negatively correlated with naturally formed wetlands. Ranid frogs were associated semi-permanent wetlands and negatively correlated with the number of other wetlands within 500 m.</div><div>Ambystomatid salamanders were found in restored wetlands, semi-permanent wetlands, and in wetlands containing central mudminnows. Frogs may dislike the disturbance from removing invasive grasses. Managers should factor the disparate habitat requirements of amphibian taxa into their plans for creating and managing restoration projects. Different amphibian groups appear to differ greatly in their habitat requirements, and diverse wetlands may enhance the species richness of an area. Skillfully restored wetlands appear to serve similar functions to original, naturally formed ones.</div>

Studies on the helminth parasites of salamanders from California have been very limited. Between September 1975 and April 1977, 340 salamander belonging to seven species, Aneides flavipunctatus (7), A. lugubris (7), Batrachoceps attenuatus attenuatus (250), Ensatina eschscholtzii eschscholtzii (52), E. e. sierrae (17), Taricha torosa (6), and Dicamptodon ensatus (1), were examined for helminths and found to harbor 10 species, four of which are new. The parasites found are: Cestoda: Distoichometra ensatinae sp. nov. from Ensatina e. eschscholtzii and E. e. sierrae; and Baerietta diana (Helfer, 1948) Douglas, 1958 from Batrachoceps a. attenuatus. Nematoda: Dibulbiger caballeroi sp. nov. from Dicamptodon ensatus; Pseudaplectana cable isp. nov. from Ensatina e. eschscholtzii, Aneides flavipunctatus, and A. lugubris; Psudaplectana waltoni sp. nov. from Batrachoceps a. attenuatus; Cosmocercoides dukae (Holl, 1928) Travassos, 1931 form, Taricha torosa; Rhabdias sp. from Taricha torosa; Thelandros salamandrae (Lehmann, 1954) Schad, 1960 from Ensatina e. eschscholtzii, Aneides flavipunctatus and A. lugubris; T. magnavulvaris (Rankin, 1937) Schad, 1963 from Taricha torosa; and T. minutus Read and Amreim, 1952 from Batrachoceps a. attenuatus. A new host record is established for Thelandros salamandrae from Ensatina e. sierrae. A host-parasite list covering work in California, Oregon, and British Columbia is also included.

Successful reproduction in salamanders is driven by behavioral, environmental, and temporal interactions among adults. While much of our understanding of salamander mating systems is based upon either courtship behavior of both sexes or aspects of female choice, the decisions made by males regarding where to place spermatophores is much less quantified. In this study, we mapped male spermatophore placement in the spotted salamander (Ambystoma maculatum) with respect to ecological and spatial locations within a vernal pool complex in Charles City County, Virginia. The overall goal was to use the spatial and ecological placement of spermatophores to determine if individuals deposit spermatophores randomly within the vernal pool or if males exhibited specific preferences for deposition. Using comprehensive surveys of the vernal pools and individual spermatophores within a 0.5m2 grid and terrestrial LIDAR, a total of 218 spermatophores were identified and mapped. We repeated these surveys for two successive breeding seasons. Placement occurred at an intermediate depth and an intermediate distance to the edge. Males also preferred to place spermatophores on leaf substrate as opposed to sticks or conifer needles. The physical placement of spermatophores exhibited autocorrelation in space during single reproductive events as well as across breeding seasons. These results suggest that males actively select for specific locations within a pool for spermatophore placement-a proverbial Goldilocks zone-which may be consistent with increased reproductive success. This information is key to understanding salamander mating system parameters in this species and may contribute to developing more effective management strategies.