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Chifu Huang - One of the best experts on this subject based on the ideXlab platform.
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An experimental study on the effects of Salamander larvae on isopods in stream pools
Freshwater Biology, 1991Co-Authors: Chifu HuangAbstract:SUMMARY 1. We used a combination of field surveys and field and laboratory experiments to examine the effects of predatory small-mouthed Salamander larvae, Ambystoma barbouri (Kraus and Petranka), on the density and microhabitat use of benthic isopods, Lirceus fontinalis (Rafinesque). 2. A survey of four field stations yielded a significant negative relationship between the densities of Salamander larvae and isopods. 3. A field experimental manipulation of Salamander density confirmed that Salamanders reduce isopod density and isopod use of open micro-habitat. Salamanders did not significantly affect the mean or coefficient of variation in isopod size. 4. A laboratory experiment showed that in the absence of refuges for isopods, Salamanders were capable of eating large numbers of isopods; small isopods were particularly vulnerable to Salamander predation.
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Experimental studies on direct and indirect interactions in a three trophic-level stream system
Oecologia, 1991Co-Authors: Chifu HuangAbstract:We used a complete block design to experimentally study direct and indirect interactions in a three trophic-level freshwater system consisting of a top predator, the green sunfish, Lepomis cyanellus , an intermediate predator, small-mouthed Salamander larvae, Ambystoma barbouri , and prey, hatchling isopods, Lirceus fontinalis . This system occurs naturally in small stream pools in central Kentucky; experiments were done in laboratory pools. Salamander larvae ate isopods and thus had a direct, negative effect on isopod survival. Accordingly, isopods responded to the presence of Salamander larvae by increasing their tendency to bury themselves in the sand substrate. Fish ate Salamanders and thus had a direct, negative effect on Salamander survival. Salamanders responded to fish presence by increasing their time spent under plexiglass plates that simulate refuge rocks. The overall effect of fish on isopods depended on the presence of Salamanders. In the absence of Salamanders, fish predation on isopods had a direct, negative effect on isopod survival; isopods thus responded to the presence of fish by burying themselves in the sand. With Salamanders present, fish had a positive overall effect on isopod survival; i.e., direct, negative effects of fish on isopods were outweighed by indirect, positive effects. Indirect positive effects of fish on isopods came through a reduction in Salamander predation rates on isopods in the presence of fish. The mechanism involved both a decrease in the number of Salamanders (a trophic-linkage indirect effect; cf. Miller and Kerfoot 1987) and a reduction in the feeding rate of individual Salamanders on isopods (a behavioral indirect effect). The decrease in individual Salamander feeding rates on isopods was due to reductions in both Salamander activity and in spatial overlap between Salamanders and isopods in the presence of fish. The latter effect reflected the fact that Salamanders and isopods used different refuges from fish; Salamanders went under refuge plates, whereas isopods primarily buried themselves in sand. Estimates of the relative importance of various direct and indirect effects of sunfish on isopods suggested that positive, behavioral indirect effects were of roughly the same magnitude as direct, negative effects, both of which were more important than were trophic-linkage indirect effects. Contrary to expectations, the presence of isopods did not affect the refuge use or survival of Salamanders in the presence of fish.
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Experimental Studies on Behaviorally Mediated, Indirect Interactions through a Shared Predator
Ecology, 1990Co-Authors: Chifu HuangAbstract:We examined indirect interactions between two noncompeting prey species (small-mouthed Salamander larvae, Ambystoma texanum, and freshwater isopods, Lirceus fontinalis) that were mediated by the prey's antipredator responses to a shared predator (green sunfish, Lepomis cyanellus). Lirceusfontinalis responded to sunfish by decreasing overall activity and by decreasing their time spent outside of refuges. Male isopods were more active than females; as a result, males suffered higher predation rates than did females. Salamander larvae tended to drive isopods out of refuges; as a result, female (but not male) isopods suffered higher predation rates with than without Salamanders. Ambystoma texanum responded to sunfish by decreasing their time spent outside of refuges. Despite this shift into refuges, A. texanum suffered high predation rates. Isopods increased the behavioral response of Salamander larvae to sunfish: A. texanum decreased their emergence rate from refuge in response to sunfish, only when isopods were present. The apparent behavioral mechanism was that with isopods present, sunfish were more active, which, in turn, elicited a stronger antipredator response from Salamanders. As a result, the presence of isopods significantly increased the survival of Salamanders when fish were also present. Salamander larvae negatively affected female isopod survival, whereas isopods posi- tively affected Salamander survival. These effects were caused by changes in antipredator behavior and thus in predation rate. The indirect interaction between Salamander larvae and isopods can be termed "apparent predation" or "indirect antagonism."
Raymond D. Semlitsch - One of the best experts on this subject based on the ideXlab platform.
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Differences in Larval Allometry among Three Ambystomatid Salamanders
Journal of Herpetology, 2016Co-Authors: Thomas L. Anderson, William E Peterman, Brittany H. Ousterhout, Dana L. Drake, Jacob J. Burkhart, Freya E. Rowland, Raymond D. SemlitschAbstract:Abstract Ecological and evolutionary processes commonly result in morphological variation among larval amphibians. Variation in head shape plays a critical role in both food capture and predation risk in gape-limited Salamanders, yet in situ studies of head shape variability are rare outside of cannibal morph assessments. We examined allometry differences in larval head width (HW) and snout–vent length (SVL) among three sympatric species of ambystomatid Salamanders from 166 ponds in Missouri, USA: Ringed Salamander (Ambystoma annulatum), Marbled Salamander (A. opacum), and Spotted Salamander (A. maculatum). We also tested whether several abiotic and biotic factors would predict HW after accounting for SVL. We found that larval HW and SVL were strongly correlated for all species but that the strength of this relationship varied among species. For early-stage larvae, Marbled Salamanders showed isometric scaling relationships, whereas both Spotted Salamanders and Ringed Salamanders were allometric. For late-...
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do golf courses reduce the ecological value of headwater streams for Salamanders in the southern appalachian mountains
Landscape and Urban Planning, 2014Co-Authors: Mark J Mackey, Grant M Connette, William E Peterman, Raymond D. SemlitschAbstract:a b s t r a c t Recent studies indicate golf courses may have a potential role in biodiversity conservation and management in human dominated landscapes. To serve this ecological role, effects of current golf course management practices must first be better understood. We sampled larval, juvenile, and adult stream Salamanders in transects located upstream, through, and downstream of managed fairways of 10 golf courses in western North Carolina, USA. We measured in-stream and riparian habitat characteristics and tested for nitrate and pesticide chemicals to explain trends in Salamander abundances and diversity. Stream transects located directly on fairways contained lower abundance of larval, metamorph, juvenile, and adult Salamanders than either upstream or downstream transects. The species diversity of aquatic larval and metamorph Salamanders on fairways was also reduced but only compared to the upstream transects, and terrestrial juvenile and adult diversity did not differ among the three transect locations. Our analysis found that leaf litter depth, CWD, soil moisture, and buffer width parameters found within several models were positive predictors of Salamander abundance and diversity. Nitrate was not detected at any of the stream reaches and two of the 16 pesticide chemicals screened were only detected in negligible proportions. Our findings suggest golf courses in western North Carolina can currently provide viable habitat for stream Salamanders in reaches upstream and downstream of managed areas of courses and streams running through fairways may be enhanced through simple management practices such as retaining woody debris, leaf litter, and restoring a riparian buffer.
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Predicting Variation in Microhabitat Utilization of Terrestrial Salamanders
Herpetologica, 2014Co-Authors: Katherine M. O'donnell, Frank R. Thompson, Raymond D. SemlitschAbstract:Understanding patterns of microhabitat use among terrestrial Salamanders is important for predicting their responses to natural and anthropogenic disturbances. The dependence of terrestrial Salamanders on cutaneous respiration limits their spatial distribution to moist, humid areas. Although many studies have shown negative effects of canopy removal on terrestrial Salamander abundance, some have shown potential ameliorating effects of retaining coarse woody debris (CWD) as moist refugia (critical resources in the landscape). Because cover objects like CWD retain moisture longer than fine debris, terrestrial Salamanders are often more locally abundant in areas of dense cover. Temporally variable environmental conditions could affect microhabitat quality and influence the fine-scale spatial distributions of Salamanders. Spatial and temporal variability in microhabitat use greatly influence individual detectability, which is always a challenge for terrestrial Salamanders. We conducted repeated area-constrained surveys to examine variation in Salamander microhabitat use of terrestrial Salamanders in relation to season, year, and weather conditions. We found that time since rain (TSR) was the best predictor of relative Salamander microhabitat use, but the strength of this relationship varied among years. In addition, TSR was also the best predictor of Salamander surface activity. We captured most Salamanders within leaf litter, but the proportion of leaf litter captures varied with TSR. Our results illustrate the importance of accounting for variable detectability when sampling for terrestrial Salamanders. Disturbances which affect leaf litter depth and decomposition rates could influence the availability and quality of microhabitats and potentially increase competition among individuals for natural cover objects.
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Effects of experimental forest management on a terrestrial, woodland Salamander in Missouri
Forest Ecology and Management, 2013Co-Authors: Daniel J. Hocking, Grant M Connette, William E Peterman, Christopher A. Conner, Brett R. Scheffers, Shannon E. Pittman, Raymond D. SemlitschAbstract:Successful multi-use planning for forested landscapes requires an understanding of timber management effects on wildlife species. Lungless, woodland Salamanders depend on forested habitats and are sensitive to changes in temperature and moisture associated with many forestry practices. Additionally, woodland Salamanders are territorial and have relatively low vagility, making it unlikely that they can successfully migrate to more favorable habitat when the surrounding forest is harvested. Therefore, we examined the abundance of the Western Slimy Salamander, Plethodon albagula, in an experimentally manipulated forest in central Missouri. We used artificial cover object searches to compare Salamander abundance in three replicate treatments that were clear-cut then burned to reduce maple regeneration, clear-cut and not burned, partially harvested, and un-manipulated control forest. We captured a total of 300 Western Slimy Salamanders between April 2007 and September 2011. We found significantly fewer Salamanders in the burn and clear-cut treatments compared with the partial and control treatments. We also found a lower proportion of juveniles and had fewer recaptures in the burn and clear-cut than in the partial and control treatments. Consistent with other studies of woodland Salamanders, our results suggest that for at least the first 7 years post-harvest, clear-cutting is detrimental to woodland Salamander populations. This initial reduction in abundance combined with the further reduced proportion of juveniles may have longer lasting effects even as the forest regenerates. Finally, it appears that timber harvest resulting in limited canopy thinning may be compatible with maintaining populations of Western Slimy Salamanders in Missouri.
Vance T Vredenburg - One of the best experts on this subject based on the ideXlab platform.
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intraspecific variation in the skin associated microbiome of a terrestrial Salamander
Microbial Ecology, 2017Co-Authors: Sofia R Pradoirwin, Alicia K Bird, Andrew G Zink, Vance T VredenburgAbstract:Resident microbial communities living on amphibian skin can have significant effects on host health, yet the basic ecology of the host-microbiome relationship of many amphibian taxa is poorly understood. We characterized intraspecific variation in the skin microbiome of the Salamander Ensatina eschscholtzii xanthoptica, a subspecies composed of four genetically distinct populations distributed throughout the San Francisco Bay Area and the Sierra Nevada mountains in California, USA. We found that Salamanders from four geographically and genetically isolated populations harbor similar skin microbial communities, which are dominated by a common core set of bacterial taxa. Additionally, within a population, the skin microbiome does not appear to differ significantly between Salamanders of different ages or sexes. In all cases, the Salamander skin microbiomes were significantly different from those of the surrounding terrestrial environment. These results suggest that the relationship between E. e. xanthoptica Salamanders and their resident skin microbiomes is conserved, possibly indicating a stable mutualism between the host and microbiome.
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intraspecific variation in the skin associated microbiome of a terrestrial Salamander
Microbial Ecology, 2017Co-Authors: Sofia R Pradoirwin, Alicia K Bird, Andrew G Zink, Vance T VredenburgAbstract:Resident microbial communities living on amphibian skin can have significant effects on host health, yet the basic ecology of the host-microbiome relationship of many amphibian taxa is poorly understood. We characterized intraspecific variation in the skin microbiome of the Salamander Ensatina eschscholtzii xanthoptica, a subspecies composed of four genetically distinct populations distributed throughout the San Francisco Bay Area and the Sierra Nevada mountains in California, USA. We found that Salamanders from four geographically and genetically isolated populations harbor similar skin microbial communities, which are dominated by a common core set of bacterial taxa. Additionally, within a population, the skin microbiome does not appear to differ significantly between Salamanders of different ages or sexes. In all cases, the Salamander skin microbiomes were significantly different from those of the surrounding terrestrial environment. These results suggest that the relationship between E. e. xanthoptica Salamanders and their resident skin microbiomes is conserved, possibly indicating a stable mutualism between the host and microbiome.
Teresa J Hanlon - One of the best experts on this subject based on the ideXlab platform.
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observer gender and observation bias in animal behaviour research experimental tests with red backed Salamanders
Animal Behaviour, 2004Co-Authors: David M. Marsh, Teresa J HanlonAbstract:Most studies of animal behaviour are based on direct observations of behaviour in a natural or laboratory context. While the potential for observation biases has often been discussed, there have been few quantitative analyses of the kinds of biases that may affect behavioural data. We used multiple observers of aggression and foraging behaviour in red-backed Salamanders, Plethodon cinereus, to investigate observation biases related to the gender of the observer. We divided observers so that half were aware of the sex of the Salamanders and the other half were kept blind to Salamander sex. We then used comparisons between blind and unblind treatments to determine the magnitude of observation biases. We found little evidence for bias due to differential perception of male and female animals by men and women observers (‘gender identification bias’) for any of the behaviours examined. Although the expectations of men and women about Salamander behaviour did sometimes differ, we also found no evidence that observers' expectations affected their observations of Salamander behaviour. However, for one component of aggressive behaviour and one component of foraging behaviour, men observed higher overall frequencies of behaviour than did women, regardless of the sex of the Salamander. Additionally, for three components of aggressive behaviour, both men and women recorded greater frequencies of behaviour when they were aware of the sex of the Salamander than when they were unaware of the Salamanders' sex. For two components of foraging behaviour, there were no significant biases with respect to the observers' gender or their knowledge of the sex of the Salamander. These results suggest that observation biases with respect to observer gender may exist for some behavioural variables, and that these biases may be relatively subtle. Although conducting blind experiments may eliminate some types of bias, our results suggest that behaviours should also be carefully screened for consistency and repeatability prior to formal data collection, even for blind experiments.
Sofia R Pradoirwin - One of the best experts on this subject based on the ideXlab platform.
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intraspecific variation in the skin associated microbiome of a terrestrial Salamander
Microbial Ecology, 2017Co-Authors: Sofia R Pradoirwin, Alicia K Bird, Andrew G Zink, Vance T VredenburgAbstract:Resident microbial communities living on amphibian skin can have significant effects on host health, yet the basic ecology of the host-microbiome relationship of many amphibian taxa is poorly understood. We characterized intraspecific variation in the skin microbiome of the Salamander Ensatina eschscholtzii xanthoptica, a subspecies composed of four genetically distinct populations distributed throughout the San Francisco Bay Area and the Sierra Nevada mountains in California, USA. We found that Salamanders from four geographically and genetically isolated populations harbor similar skin microbial communities, which are dominated by a common core set of bacterial taxa. Additionally, within a population, the skin microbiome does not appear to differ significantly between Salamanders of different ages or sexes. In all cases, the Salamander skin microbiomes were significantly different from those of the surrounding terrestrial environment. These results suggest that the relationship between E. e. xanthoptica Salamanders and their resident skin microbiomes is conserved, possibly indicating a stable mutualism between the host and microbiome.
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intraspecific variation in the skin associated microbiome of a terrestrial Salamander
Microbial Ecology, 2017Co-Authors: Sofia R Pradoirwin, Alicia K Bird, Andrew G Zink, Vance T VredenburgAbstract:Resident microbial communities living on amphibian skin can have significant effects on host health, yet the basic ecology of the host-microbiome relationship of many amphibian taxa is poorly understood. We characterized intraspecific variation in the skin microbiome of the Salamander Ensatina eschscholtzii xanthoptica, a subspecies composed of four genetically distinct populations distributed throughout the San Francisco Bay Area and the Sierra Nevada mountains in California, USA. We found that Salamanders from four geographically and genetically isolated populations harbor similar skin microbial communities, which are dominated by a common core set of bacterial taxa. Additionally, within a population, the skin microbiome does not appear to differ significantly between Salamanders of different ages or sexes. In all cases, the Salamander skin microbiomes were significantly different from those of the surrounding terrestrial environment. These results suggest that the relationship between E. e. xanthoptica Salamanders and their resident skin microbiomes is conserved, possibly indicating a stable mutualism between the host and microbiome.
