Correlates and consequences of injury in a large, predatory stream salamander (Dicamptodon tenebrosus)

in Amphibia-Reptilia
No Access
Get Access to Full Text
Rent on DeepDyve

Have an Access Token?

Enter your access token to activate and access content online.

Please login and go to your personal user account to enter your access token.


Have Institutional Access?

Access content through your institution. Any other coaching guidance?


Conspecific aggression is an important factor structuring population dynamics through intra- and interspecific interactions, but is rarely studied in un-manipulated populations. In this study, we evaluated rates of injury as a proxy for conspecific aggression using a depletion survey of predatory coastal giant salamanders (Dicamptodon tenebrosus) in a tributary of the South Fork Eel River, California. We tested a range of hypotheses including a suite of environmental and biotic factors for the rate of injury in a population by using an AIC model-selection approach that examined the weight of evidence for individual models. We examined both the probability of a given individual being injured, and the proportion of individuals within a given study pool being injured. We found strong support for models including salamander size, density of young-of-the-year steelhead, and density of the largest size-class of salamander as factors positively influencing the rate of injury at both the individual and habitat levels. We also found that density of older steelhead (1+ steelhead) had a strong, but highly variable positive impact on frequency of injury. This study shows that both conspecific and heterospecific factors influence intraspecific aggression for the dominant salamander throughout coastal Pacific Northwest streams. Our methodology demonstrates a non-manipulative approach to identifying correlates of natural injury in a cryptic species of amphibian. More work is needed to determine how these factors directly and indirectly influence the spatial distribution, individual fitness, and dynamics of salamander populations within streams.

Correlates and consequences of injury in a large, predatory stream salamander (Dicamptodon tenebrosus)

in Amphibia-Reptilia



  • AkaikeH. (1974): A new look at the statistical model identification. IEEE Transactions on Automatic Control 19: 716-723.

  • AndersonD.R.BurnhamK.P. (2002): Avoiding pitfalls when using information-theoretic methods. The Journal of Wildlife Management 66: 912-918.

  • AntonelliA.L.NassbaumR.SmithS.D. (1972): Comparative food habits of four species of stream-dwelling vertebrates (Dicamptodon ensatis, D. copei, Cottus tenuis, Salmo gairdneri). Northwest Scientist 46: 277-289.

  • AtlasW.I.PalenW.J.CourcellesD.M.MunshawR.G.MonteithZ.L. (2013): Dependence of stream predators on terrestrial prey fluxes: food web responses to subsidized predation. Ecosphere 4: art69.

  • BeachyC.K. (1994): Community ecology in streams: effects of two species of predatory salamanders on a prey species of salamander. Herpetologica 50: 129-136.

  • BrodmanR. (1996): Effects of intraguild interactions on fitness and microhabitat use of larval Ambystoma salamanders. Copeia 1996: 372-378.

  • BrodmanR. (2004): Intraguild predation on congeners affects size, aggression, and survival among Ambystoma salamander larvae. Journal of Herpetology 38: 21-26.

  • BrunkowP.E.CollinsJ.P. (1998): Group size structure affects patterns of aggression in larval salamanders. Behavioral Ecology 9: 508-514.

  • BurnhamK.P.AndersonD.R. (2002): Model Selection and Multi-Model Inference: A Practical Information-Theoretic Approach. Springer.

  • CrockettC.M.PopeT. (1988): Inferring patterns of aggression from red howler monkey injuries. American Journal of Primatology 15: 289-308.

  • Da Silva NunesV.JaegerR.G. (1989): Salamander aggressiveness increases with length of territorial ownership. Copeia 1989: 712-718.

  • FergusonM.W.J.O’KaneS. (2004): Scar-free healing: from embryonic mechanisms to adult therapeutic intervention. Phil. Trans. R. Soc. Lond. B 359: 839-850.

  • FigielC.R.SemlitschR.D. (1990): Population variation in survival and metamorphosis of larval salamanders (Ambystoma maculatum) in the presence and absence of fish predation. Copeia 1990: 818-826.

  • FitzpatrickL.C. (1976): Life history patterns of storage and utilization of lipids for energy in amphibians. Amer. Zool. 16: 725-732.

  • FormanowiczD.R.BrodieE.D. (1993): Size-mediated predation pressure in a salamander community. Herpetologica 49: 265-270.

  • GoodD.A. (1989): Hybridization and cryptic species in Dicamptodon (Caudata: Dicamptodontidae). Evolution 43: 728-744.

  • GrubbsF.E. (1950): Sample criteria for testing outlying observations. Ann. Math. Statist. 21: 27-58.

  • HahnS.PeterH.-U. (2003): Feeding territoriality and the reproductive consequences in brown skuas Catharacta antarctica lonnbergi. Polar. Biol. 26: 552-559.

  • HofmannH.A.SchildbergerK. (2001): Assessment of strength and willingness to fight during aggressive encounters in crickets. Animal Behaviour 62: 337-348.

  • HsuY.EarleyR.L.WolfL.L. (2007): Modulation of aggressive behaviour by fighting experience: mechanisms and contest outcomes. Biological Reviews 81: 33-74.

  • HugieD.M.DillL.M. (1994): Fish and game: a game theoretic approach to habitat selection by predators and prey. Journal of Fish Biology 45: 151-169.

  • JaegerR.G. (1981): Dear enemy recognition and the costs of aggression between salamanders. American Naturalist 117: 962-974.

  • JaegerR.G. (1984): Agonistic behavior of the red-backed salamander. Copeia 1984: 309-314.

  • JohnssonJ.I.NöbbelinF.BohlinT. (1999): Territorial competition among wild brown trout fry: effects of ownership and body size. Journal of Fish Biology 54: 469-472.

  • KleebergerS.R. (1984): A test of competition in two sympatric populations of desmognathine salamanders. Ecology 65: 1846-1856.

  • KrauseE.T.SteinfartzS.CaspersB.A. (2011): Poor nutritional conditions during the early larval stage reduce risk-taking activities of fire salamander larvae (Salamandra salamandra). Ethology 117: 416-421.

  • MarvinG.A. (1998): Territorial behavior of the plethodontid salamander Plethodon kentucki: influence of habitat structure and population density. Oecologia 114: 133-144.

  • MathisA. (1990): Territoriality in a terrestrial salamander: the influence of resource quality and body size. Behaviour 112: 162-175.

  • MazerolleM.J. (2013): AICcmodavg: Model selection and multimodel inference based on (Q)AIC(c). Retrieved from

  • MottC.L.SparlingD.W. (2009): Ontogenetic patterns of agonistic behavior in a guild of larval ambystomatid salamanders. Journal of Herpetology 43: 532-540.

  • MunshawR.G.PalenW.J.CourcellesD.M.FinlayJ.C. (2013): Predator-driven nutrient recycling in California stream ecosystems. PLoS ONE 8: e58542.

  • NehlsenW. (1997): Pacific Salmon Their Ecosystems: Status and Future Options. StouderD.J.BissonP.A.NaimanR.J. Eds Springer.

  • NussbaumR.A.BrodieE.D.StormR.M. (1983): Amphibians and reptiles of the Pacific northwest. University Press of Idaho.

  • NussbaumR.A.ClothierG.W. (1973): Population structure, growth, and size of larval Dicamptodon ensatus (Eschscholtz). Northwest Science 47: 218-277.

  • ParkerM.S. (1993): Predation by Pacific giant salamander larvae on juvenile steelhead trout. Northwestern Naturalist 74: 77-81.

  • ParkerM.S. (1994): Feeding ecology of stream-dwelling Pacific giant salamander larvae (Dicamptodon tenebrosus). Copeia 1994: 705-718.

  • R Core Team (2013): R: A Language and Environment for Statistical Computing. ViennaAustria. Retrieved from

  • ResetaritsW.J.Jr. (1991): Ecological interactions among predators in experimental stream communities. Ecology 72: 1782-1793.

  • RoudebushR.E.TaylorD.H. (1987): Behavioral interactions between two desmognathine salamander species: importance of competition and predation. Ecology 68: 1453-1458.

  • RudolfV.H.W. (2008): Impact of cannibalism on predator-prey dynamics: Size-structured interactions and apparent mutualism. Ecology 89: 1650-1660.

  • RundioD.E.OlsonD.H.GuyerC. (2003): Antipredator defenses of larval Pacific giant salamanders (Dicamptodon tenebrosus) against cutthroat trout (Oncorhynchus clarki). Copeia 2003: 402-407.

  • SchoenerT.W.SchoenerA. (1980): Ecological and demographic correlates of injury rates in some Bahamian Anolis lizards. Copeia 1980: 839-850.

  • ScottD.E.CaseyE.D.DonovanM.F.LynchT.K. (2007): Amphibian lipid levels at metamorphosis correlate to post-metamorphic terrestrial survival. Oecologia 153: 521-532.

  • SeifertA.W.MonaghanJ.R.VossS.R.MadenM. (2012): Skin regeneration in adult axolotls: a blueprint for scar-free healing in vertebrates. PLoS ONE 7: e32875.

  • SemlitschR.D. (1990): Effects of body size, sibship, and tail injury on the susceptibility of tadpoles to dragonfly predation. Canadian Journal of Zoology 68: 1027-1030.

  • SemlitschR.D.ReichlingS.B. (1989): Density-dependent injury in larval salamanders. Oecologia 81 (1): 100-103.

  • SepulvedaS.ShojaeianP.RauserC.L.JafariM.MuellerL.D.RoseM.R. (2008): Interactions between injury, stress resistance, reproduction, and aging in Drosophila melanogaster. Experimental Gerontology 43: 136-145.

  • ShapovalovL.TaftA.C. (1954): Fish Bulletin No. 98. The life histories of the steelhead rainbow trout (Salmo gairdneri gairdneri) and silver salmon (Oncorhynchus kisutch) with special reference to Waddell Creek California and recommendations regarding their management. Fish Bulletin. Retrieved from

  • SlaneyP.A.NorthcoteT.G. (1974): Effects of prey abundance on density and territorial behavior of young rainbow trout (Salmo gairdneri) in Laboratory Stream Channels. Journal of the Fisheries Research Board of Canada 31: 1201-1209.

  • StuartS.N.ChansonJ.S.CoxN.A.YoungB.E.RodriguesA.S.L. (2007): A comparison of the effectiveness of recommended doses of MS-222 (tricaine methanesulfonate) and Orajel® (benzocaine) for amphibian anesthesia. Herpetological Review 38: 63-66.

  • SymondsM.R.E.MoussalliA. (2011): A brief guide to model selection, multimodel inference and model averaging in behavioural ecology using Akaike’s information criterion. Behav. Ecol. Sociobiol. 65: 13-21.

  • TornickJ.K. (2010): Factors affecting aggression during nest guarding in the eastern red-backed salamander (Plethodon cinereus). Herpetologica 66: 385-392.

  • WildyE.L.ChiversD.P.KieseckerJ.M.BlausteinA.R. (2001): The effects of food level and conspecific density on biting and cannibalism in larval long-toed salamanders, Ambystoma macrodactylum. Oecologia 128: 202-209.

  • WiltenmuthE.B. (1997): Agonistic behavior and use of cover by stream-dwelling larval salamanders (Eurycea wilderae). Copeia 1997: 439-443.

  • YannasI.V.ColtJ.WaiY.C. (1996): Wound contraction and scar synthesis during development of the amphibian Rana catesbeiana. Wound Repair and Regeneration 4: 29-39.


  • View in gallery

    Histogram of salamander snout to vent length (SVL, mm) from Fox Cr. (n=354). Vertical lines indicate divisions between size-classes as established in the literature.

  • View in gallery

    Predicted mass residuals (g) for each size-class of injured salamander based on a mass-length regression for uninjured individuals. Stars indicate size classes with residuals that differ significantly from 0.

  • View in gallery

    Model-averaged variable importance scores (sum of Akaike weights; wAk) for individual-level (light bars) and habitat-level (dark bars) analyses. Importance computed by summing Akaike weights for every model in which each variable was present. SDSVL = standard deviation of salamander snout-vent lengths in a given pool, DSC3 = density of size-class 3 salamanders in a given pool (#/m2), SVL = snout-vent of the focal salamander (mm), DYOY = density of young-of-the-year steelhead in a given pool (#/m2), D1+ = density of 1+ steelhead in a given pool (#/m2), d = square root of distance upstream (m), and D = salamander biomass density (g/m2).


Content Metrics

Content Metrics

All Time Past Year Past 30 Days
Abstract Views 15 15 6
Full Text Views 128 128 8
PDF Downloads 6 6 1
EPUB Downloads 0 0 0