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Book Feeding Ecology of Larvae of the Pacific Giant Salamander Dicamptodon Tenebrosus and Their Role as Top Predator in a Headwater Stream Benthic Community

Download or read book Feeding Ecology of Larvae of the Pacific Giant Salamander Dicamptodon Tenebrosus and Their Role as Top Predator in a Headwater Stream Benthic Community written by Michael S. Parker (Professor of biology) and published by . This book was released on 1992 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Movement and Demography of Larval Coastal Giant Salamanders Dicamptodon Tenebrosus in Streams with Culverts in the Oregon Coast Range

Download or read book Movement and Demography of Larval Coastal Giant Salamanders Dicamptodon Tenebrosus in Streams with Culverts in the Oregon Coast Range written by Jina P. Sagar and published by . This book was released on 2004 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Barriers to the movement of aquatic organisms can increase the genetic and spatial isolation of populations and may decrease the viability of these regional populations. Focus on culvert passage issues has increased as federal agencies attempt to inventory and replace road-crossing stream culverts that are barriers to the movement of anadromous fish. However, the effect of road-crossing culverts on the movement of other aquatic organisms is not known. The coastal giant salamander (Dicamptodon tenebrosus) is an important component of headwater stream communities and their movement may be affected by culverts in the larval aquatic stage. The objectives of this study were to determine the effect of road-crossing culverts on the movement and survival of larval coastal giant salamanders in the Oregon Coast Range. We conducted a mark-recapture study on larval D. tenebrosus 3rd and 4th order streams to: i) determine culvert use and passage by design type (pipe and arch types) relative to reference stream reaches without culverts; and ii) model larval survival and growth by season, age and culvert presence. We assessed the movement of over 2,000 larval D. tenebrosus in 14 streams and found that larvae were highly sedentary. Mean movement distances did not differ with culvert presence. However, a small portion of larvae (20%) moved sufficient distances to assess culvert passage. Larvae moved less frequently through stream reaches with culverts than stream reaches without culverts, suggesting a barrier effect. There was less upstream movement through pipe culverts than arch culverts. Also, there were lower larval densities in pipe culverts, indicating arch culverts provided more larval habitat. Larval density both inside culverts and in the adjacent stream reaches was associated with the presence of large substrates, which may be important in facilitating larval D. tenebrosus movement through culverts. Stream reaches with culverts were associated with higher levels of fine sediments, however, which may reduce the suitability of near-culvert habitats. Survival estimates indicated high selection pressure early in the larval period. Apparent survival was lower in summer, and for first-year larvae in comparison to second/third-year larvae. Larval survival for both age groups was lower in reaches of stream with culverts although this effect was weak. Culvert effects on movement of coastal giant salamander aquatic larvae indicate they can operate as barriers but their effect on survival remains unclear. Culvert replacements that simulate both the natural stream bed and hydraulic conditions would help provide both habitat and passage opportunities for larval D. tenebrosus.

Book Riparian Vegetation and Larval Pacific Giant Dicamptodon Tenebrosus and Adult Western Redback Plethodon Vehiculum Salamanders in the Oregon Coast Range

Download or read book Riparian Vegetation and Larval Pacific Giant Dicamptodon Tenebrosus and Adult Western Redback Plethodon Vehiculum Salamanders in the Oregon Coast Range written by Paula Hayes Graff and published by . This book was released on 2006 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Riparian areas in the Pacific Northwest provide important biotic and abiotic features, such as down wood, moist microsites, and abundant invertebrate prey that benefit aquatic and terrestrial amphibians. Reported high densities of amphibians from streams and riparian areas in the Pacific Northwest highlight their importance in riparian food webs. Amphibians provide an important trophic link between terrestrial and aquatic systems because they may exploit both terrestrial and aquatic prey and in turn they are prey for other vertebrates. In the Oregon Coast Range, riparian vegetation is often more diverse than upland vegetation and there is typically a considerable deciduous component. However, forestry regulations in Oregon require landowners to promote the growth of conifer over deciduous trees in riparian areas to benefit salmonids and other fishes. The goal of our research was to examine associations between the distribution and diets of aquatic and terrestrial amphibians and vegetation in second- and third-order Oregon Coast Range streams and riparian areas. Sites reflected overstory conditions in managed forests of the central Oregon Coast Range, ranging from primarily red alder (Alnus rubra) in the riparian zone to mostly Douglas- fir (Pseudotsuga menziesii). The two most common amphibians detected were the aquatic Pacific Giant Salamander larvae (Dicamptodon tenebrosus) and the terrestrial Western Redback Salamander (Plethodon vehiculum). Our first research objective was to identify habitat characteristics with an emphasis on riparian vegetation, that could be associated with the presence of these two species. We used logistic regression to examine the presence of these salamanders among sites and the information-theoretic approach using Akaike Information Criterion (AIC) methods to compare the strength of evidence of a set of candidate models formed from a priori hypotheses. The highest ranked model explained 95% of the variability of the presence of Dicamptodon tenebrosus larvae among sites and included variables representing percent cover of Douglas- fir, elevation, amount of wood cover, and lithology type. The odds of the presence of D. tenebrosus increased with the percent cover of Douglas- fir over the wetted width of the stream. Two competitive models (

Book Spatial Ecology Behavior and Habitat Use of Terrestrial Coastal Giant Salamanders Dicamptodon Tenebrosus in the Central Washington Cascades

Download or read book Spatial Ecology Behavior and Habitat Use of Terrestrial Coastal Giant Salamanders Dicamptodon Tenebrosus in the Central Washington Cascades written by Brandon Fessler and published by . This book was released on 2012 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Measuring the Effects of Increasing Loads of Fine Sediment from Timber Harvest and Road Building on Aquatic Populations of Dicamptodon Tenebrosus pacific Giant Salamander in California s Redwoods

Download or read book Measuring the Effects of Increasing Loads of Fine Sediment from Timber Harvest and Road Building on Aquatic Populations of Dicamptodon Tenebrosus pacific Giant Salamander in California s Redwoods written by Seth Pogue and published by . This book was released on 2008 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dicamptodon tenebrosus (Pacific giant salamander) was evaluated for suitability as an indicator of aquatic habitat quality relative to increasing loads of fine sediment from timber harvest and road building. I compared three surrogates of D. tenebrosus population success - biomass per unit area, density, and number of age classes (dependent variables) to two measures of stream sedimentation - RSI, which measures how much of the stream bed becomes mobilized at peak flow, and D50, the median bed particle diameter (independent variables) on 49 streams from three subjective disturbance categories: a control group, a moderate management group, and a high management group. Streams impacted by sediment exhibited fewer surviving age classes, and also significantly less biomass per square meter of pool bottom. These streams were from the moderate and high management categories. Unimpacted streams (control group) exhibited the greatest number of surviving age classes and the highest biomass. This study also presents the first quantitative analysis of D. tenebrosus age class structure. These animals live to be at least twelve years old.

Book Pacific Giant Salamander

Download or read book Pacific Giant Salamander written by Donald A. Blood and published by Province of British Columbia, Ministry of Environment, Lands and Parks. This book was released on 1993 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Life History Variables of Dicamptodon Salamanders

Download or read book Life History Variables of Dicamptodon Salamanders written by Lisa A. Wagner and published by . This book was released on 2014 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is good practice to fully understand components of an ecosystem if we hope to preserve its biodiversity. A problem is that we know very little about some organisms and nothing of others. Studies that investigate an organism's basic biological, ecological and physiological life history variables advance our knowledge of the species of interest and also offer insight about community structure and function. In this thesis I explore courtship behaviors, metamorphic tendencies and hematological parameters in two species of Dicamptodon salamanders (D. copei and D. tenebrosus). Ecologists examine blood to assess hematological responses to a plethora of factors including hormonal changes, parasites, reproductive status and environmental stressors. While hematologic principles are fairly conserved in vertebrates, blood tissue has evolved to match the organism with its environment and there is considerable diversity in hematological parameters across taxa. Therefore, it is necessary to collect species specific baseline data for comparison. In Chapter 2, I quantified relative white blood cells and erythrocyte dry volume measurements of both D. tenebrosus and D. copei in the wild and in captivity. No prior studies have evaluated the hematological parameters of Dicamptodon salamanders. My investigation revealed similar leukocyte ratios between species and between wild and captive D. tenebrosus, while leukocyte ratios of wild and captive D. copei were significantly different. Dicamptodon species and populations vary in metamorphic tendencies though the reasons for this variation are not known. In Chapter 3 I investigated the difference in metamorphic tendencies of D. copei and D. tenebrosus. First, I tested the hypotheses that high water inhibits and thermal stress induces metamorphosis. Neither lowered water, nor increased aquatic temperatures induced metamorphosis. Secondly, I compared thermal preferences of both species and found differences in the selection tendencies between species and between sizes of both species. Lastly, I stress responses of both species to 1.66o C, 21.11oC and 25o C water using a hematological approach. This study revealed significant differences in hematological stress indices between the two species. In Chapter 4, I explored the courtship behaviors of D. copei and D. tenebrosus and characterized each behavior and temporal pattern, using a phyloethological approach. I then compared these courtship behaviors between species and to that of the nearest salamander family, Ambystomatidae. The courtship patterns and behaviors were similar in both species, but they did not resemble the courtship patterns or behaviors of their sister taxon, Ambystoma.

Book The Influence of Abiotic and Biotic Environmental Factors at High Elevation on the Life Cycle of a Facultatively Paedomorphic Salamander

Download or read book The Influence of Abiotic and Biotic Environmental Factors at High Elevation on the Life Cycle of a Facultatively Paedomorphic Salamander written by Elijah Carl White and published by . This book was released on 2016 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Comparison of Methods to Estimate Population Density of Pacific Giant Salamanders in Small Streams of the Southern Oregon Cascades

Download or read book Comparison of Methods to Estimate Population Density of Pacific Giant Salamanders in Small Streams of the Southern Oregon Cascades written by Niels C. Leuthold and published by . This book was released on 2003 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: I compared hand sampling, two-pass multiple removal sampling, mark-recapture and catchability-based population estimates for the Pacific giant salamander (Dicamptodon tenebrosus) at 22 sites in 11 streams of Cascade Mountains of Oregon. Mark-recapture and catchability-based population estimates were not significantly different (p 0.86). Hand sampling and two-pass multiple removal population estimates were not significantly different (p = 0.57). However, mark-recapture and catchability-based estimates were significantly greater than two-pass multiple removal and hand sampling estimates. Hand sampling and multiple removal population estimates were frequently lower than the number of individual Pacific giant salamanders captured by all methods at a site. The catchability of each method differed between streams and within consecutive sites on the same stream. Unacknowledged differences in catchabilities among sites are a potential source of error when using hand-sampling index counts to estimate and compare populations without correcting the estimates for the differences in Pacific giant salamander catchability. Catchability decreased significantly between the first pass of electroshocking and the subsequent recapture pass of electroshocking. This decrease was observed even though the recapture passes were performed the day after the multiple removal electroshocking. A decrease in catchability violates the assumptions of constant catchability for multiple removal population estimates and potentially explains the weaker performance of removal estimates. Hand sampling estimates did not adjust for the proportion of the population captured at each site, and this is probably the cause of their poor performance. The presumption of constant catchability in hand sampling produced biases in the population estimates, because the catchabilities were not constant. In future studies of stream amphibian abundance, catchability needs to be included in population estimation procedures to produce accurate estimates and to allow valid comparisons of population sizes between sites. Catchability models can be used to calibrate less intensive survey methods, such as hand sampling or a single pass of electroshocking, with the results from more intensive mark-recapture methods. Intensive work would be needed to do the calibrations, but afterwards a standard, more convenient method, such as electroshocking or hand sampling, can be used within the ranges of habitat values for which the calibration model is valid.

Book Speciation Phylogeography and Gene Flow in Giant Salamanders Dicamptodon

Download or read book Speciation Phylogeography and Gene Flow in Giant Salamanders Dicamptodon written by Craig A. Steele and published by . This book was released on 2006 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Giant salamanders of the genus Dicamptodon occur in the Pacific Northwest of North America. The variety of geographic distributions and life history traits displayed among this genus provide opportunities to test hypotheses concerning regional biogeography, effects of Pleistocene glaciation, comparative phylogeography, and patterns of gene flow. A genus-level phylogeny was constructed to test competing biogeographic hypotheses concerning the disjunct distribution of the Idaho giant salamander (D. aterrimus ), and a Pleistocene speciation hypothesis for the Cope's giant salamander (D. copei). Results indicate speciation and distribution of D. aterrimus is attributable to the orogeny of the Cascade Mountains rather than recent inland dispersal and that D. copei is distantly related to other coastal species and likely originated much earlier than the Pleistocene. Patterns of intraspecific variation were examined for the widespread Pacific giant salamander (D. tenebrosus) and hypotheses concerning the location and number of Pleistocene refugia were tested. Results indicate that D. tenebrosus was restricted to two Pleistocene refugia, one in the Columbia River valley and another in the Klamath-Siskiyou Mountains, and has recently expanded northward from these refugia into its current distribution. Phylogeographic patterns for D. copei were compared to that of the codistributed Van Dyke's salamander (Plethodon vandykei). Results reveal that sympatric populations displayed identical phylogeographic topologies, suggesting shared evolutionary histories, but topologies were ultimately incongruent due to several highly divergent allopatric populations of D. copei. Comparative patterns of genetic population structure were examined for sympatric populations of D. tenebrosus and D. copei. Results indicate that the metamorphosing species, D. tenebrosus, displayed a lack of population structure while the non-metamorphosing species, D. copei, displayed a larger degree of population structure. These results help explain the phylogeographic patterns presented for each species. The large distribution and post-glacial expansion by D. tenebrosus was facilitated by its high dispersal ability while the low dispersal ability of D. copei lead to a small and fragmented geographic range and greater phylogeographic structure within its range. These results suggest that understanding life history variation on a local scale can lead to a better understanding of the mechanistic underpinnings of species' distributions in general.

Book Recovery Strategy for the Coastal Giant Salamander Dicamptodon Tenebrosus in Canada

Download or read book Recovery Strategy for the Coastal Giant Salamander Dicamptodon Tenebrosus in Canada written by and published by . This book was released on 2017 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Canadian distribution of this salamander is restricted to the Chilliwack drainage system in southwestern British Columbia, where it occurs mainly in cool, clear mountain streams and surrounding riparian forest. Major threats include habitat loss, degradation and fragmentation due to forest harvest, road building, and encroaching residential development. These threats may be exacerbated by droughts and flooding events that are predicted to increase with climate change. Poor dispersal ability, low reproductive rate, late maturity, and long generation time increase the vulnerability of the species"--Reason for designation, p. 5.

Book Recovery Strategy for the Coastal Giant Salamander Dicamptodon Tenebrosus in Canada

Download or read book Recovery Strategy for the Coastal Giant Salamander Dicamptodon Tenebrosus in Canada written by and published by . This book was released on 2017 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Canadian distribution of this salamander is restricted to the Chilliwack drainage system in southwestern British Columbia, where it occurs mainly in cool, clear mountain streams and surrounding riparian forest. Major threats include habitat loss, degradation and fragmentation due to forest harvest, road building, and encroaching residential development. These threats may be exacerbated by droughts and flooding events that are predicted to increase with climate change. Poor dispersal ability, low reproductive rate, late maturity, and long generation time increase the vulnerability of the species"--Reason for designation, p. 5.