Abstract
Size-specific interactions between predators can affect both species population dynamics and the structure and biodiversity of communities they inhabit. Interactions between size-structured populations of predators, especially those with complex life-cycles, often change with resource-use changes driven by ontogenetic niche shifts. However, if resource use is determined largely by prey size, generalist predators may compete across a wider range of body sizes and life stages resulting in diffuse intra- and interspecific competition. We examined size- and stage-specific interactions between juvenile sirens (Siren i. intermedia) and adult newts (Notophthalmus viridescens dorsalis) in the context of previous experiments demonstrating competitive equality of larvae and strong effects of adult S. intermedia on adult N. viridescens. Competition between juvenile siren and adult newts was mutually negative and roughly symmetrical. Two S. intermedia reduced growth of three N. viridescens by 21%, while three N. viridescens reduced growth of two S. intermedia by 29%. Together with previous work, this implicates diffuse competition as a critical feature in the ecology of these species across the range of body sizes and suggests that intensity of competition varies more with size than species identity. Competition that varies incrementally with body size expands the realm of possibilities for continuous niche changes and diffuse competition across large size gradients. For generalist predators such as S. intermedia and N. viridescens, body size, except at the extremes, is not an adequate niche difference either intra- or interspecifically.
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Abbreviations
- ANOVA:
-
Analysis of Variance
- MANOVA:
-
Multivariate Analyis of Variance
- SVL:
-
Snout to posterior margin of vent
- TL:
-
Total length
References
Abrams, P. A. 1994. Evolutionarily stable growth rates in size-structured populations under size-related competition. Theor. Pop. Biol. 46:78–95.
Altig, R. 1967. Food of Siren intermedia nettingi in a spring-fed swamp in southern Illinois. Am. Midl. Nat. 77:239–241.
Brodie, E.D. Jr, J. L. Hensel, Jr. and J. A. Johnson. 1974. Toxicity of the urodele amphibians Taricha, Notophthalmus, Cynops and Paramesotriton (Salamandridae). Copeia 1974:506–511.
Chalcraft, D. R. and W. J. Resetarits, Jr. 2004. Metabolic rate models and the substitutability of predator populations. J. Anim. Ecol. 73:323–332.
Claessen, D., A. M. de Roos, and L. Persson. 2000. Dwarfs and giants: Cannibalism and competition in size-structured populations. Am. Nat. 155:219–237.
Collette, B.B. and F. R. Gehlbach. 1961. The salamander Siren intermedia intermedia LeConte in North Carolina. Herpetologica 17:203–204.
Crother, B. I. (ed.). 2000. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding. SSAR Herpetological Circular 29. iii + 82 pp.
de Roos, A. M. and L. Persson, L. 2001. Physiologically structured models: From versatile technique to ecological theory. Oikos 94:51–71.
Ebenman, B. 1987. Niche differences between age classes and intraspecific competition in age-structured populations. J. Theor. Biol. 124:25–33.
Ebenman, B. and L. Persson (eds) 1988. Size-structured Populations: Ecology and Evolution. Springer-Verlag, Berlin, Germany.
Fauth, J. E. and W. J. Resetarits Jr. 1991. Interactions between the salamander Siren intermedia and the keystone predator Notophthalmus viridescens. Ecology 72:827–838.
Fauth, J. E., W. J. Resetarits Jr and H. M. Wilbur. 1990. Interactions between larval salamanders: a case of competitive equality. Oikos 58:91–99.
Fisher Huckins, C. J. 1997. Functional linkages among morphology, feeding performance, diet, and competitive ability in mollus-civorous sunfish. Ecology 78:2401–2414.
Gehlbach, F.R. and S. E. Kennedy. 1978. Population ecology of a highly productive aquatic salamander (Siren intermedia). Southwest. Nat. 23:423–430.
Gehlbach, F.R., R. Gordon and J. B. Neill. 1973. Aestivation of the salamander, Siren intermedia. Am. Midl. Nat. 89:455–463.
Gill, D. E. 1978. The metapopulation dynamics of the red spotted newt, Notophthalmus viridescens (Rafinesque). Ecol. Monogr. 48:145–166.
Gill, D. E. 1979. Density dependence and homing behavior in adult red-spotted newts Notophthalmus viridescens (Rafinesque). Ecology 60:800–813.
Godley, J .S. 1983. Observations on the courtship, nests and young of Siren intermedia in southern Florida. Am. Midl. Nat. 110:215–219.
Hamilton, W. J. Jr. 1940. The feeding habits of larval newts with reference to availability and predilection of food items. Ecology 21:351–356.
Harris, R. N. 1987a. Density-dependent paedomorphosis in the salamander Notophthalmus viridescens dorsalis. Ecology 68:705–712.
Harris, R. N. 1987b. An experimental study of population regulation in the salamander, Notophthalmus viridescens dorsalis (Urodela: Salamandridae). Oecologia 71: 280–285.
Harris, R. N., R. A. Alford and H. M. Wilbur. 1988. Density and phenology of Notophthalmus viridescens dorsalis in a natural pond. Herpetologica 4:234–242.
Martof, B. S. 1969. Prolonged inanation in Siren lacertina. Copeia 1969:285–289.
Martof, B. S. 1973. Siren intermedia. Catalogue of American Amphibians and Reptiles. Society for the Study of Amphibians and Reptiles: 127.1–127.3.
Mittlebach, G. G., C. W. Osenberg and M. A.Leibold. 1988. Trophic relations and ontogenetic niche shifts in aquatic ecosystems. In: B. Ebenman and L. Persson (eds.), Size-structured Populations: Ecology and Evolution. Springer-Verlag, Berlin, pp. 219–235.
Morin, P. J. 1981. Predatory salamanders reverse the outcome of competition among three species of anuran tadpoles. Science 212:1284–1286.
Morin, P. J. 1983a. Predation, competition, and the structure of larval anuran guilds. Ecol. Monogr. 53: 119–138.
Morin, P. J. 1983b. Competitive and predatory interactions in natural and experimental populations of Notophthalmus viridescens dorsalis and Ambystoma tigrinum. Copeia 1983:628–639.
Muotka, T. 1990. Coexistence in a guild of filter-feeding caddis larvae: do different instars act as different species? Oecologia 85:281–292.
Norberg, R. A. 1988. Self-thinning of plant populations dictated by packing density and individual growth geometry and relationships between animal population density and body mass governed by metabolic rate. In: B. Ebenman and L. Persson (eds.), Size-structured Populations: Ecology and Evolution. Springer-Verlag, Berlin, pp. 259–279.
Persson, L. 1985. Asymmetrical competition: Are larger animals competitively superior? Am. Nat. 126:261–266.
Persson, L. 1988. Asymmetries in competitive and predatory interactions in fish populations. In: B. Ebenman and L. Persson (eds.), Size-structured Populations: Ecology and Evolution. Springer-Verlag, Berlin, pp. 203–218.
Persson, L., and P. Eklov. 1995. Prey refuges affecting interactions between piscivorous perch and juvenile perch and roach. Ecology 76:70–81.
Polis, G. A. 1984. Age structure component of niche width and intraspecific resource partitioning: can age groups function as ecological species? Am. Nat. 123:541–564.
Polis, G. A. 1988. Exploitation competition and the evolution of interference, cannibalism, and intraguild predation in age/size-structured populations. In: B. Ebenman and L. Persson (eds.), Size-structured Populations: Ecology and Evolution. Springer-Verlag, Berlin, pp. 185–202.
Polis, G. A. and S. J. McCormick. 1987. Intraguild predation and competition among desert scorpions. Ecology 68:332–343.
Reilly, S. R. 1987. Ontogeny of the hyobranchial apparatus in the salamanders Ambystoma talpoideum (Ambystomatidae) and Notophthalmus viridescens (Salamandridae): the ecological morphology of two neotenic strategies. J. Morph. 191:205–214.
Resetarits, W. J., Jr. 1995a. Competitive asymmetry and coexistence in size-structured populations of brook trout and spring salamanders. Oikos 73: 188–198.
Resetarits, W. J., Jr. 1995b. Limiting similarity and the intensity of competitive effects on the mottled sculpin, Cottus bairdi, in experimental stream communities. Oecologia 104: 31–38.
Resetarits, W. J., Jr. 1997. Interspecific competition and qualitative competitive asymmetry between two benthic stream fish. Oikos 78:429–439.
Resetarits, W. J., Jr. and J. E. Fauth. 1998. From cattle tanks to Carolina Bays: the utility of model systems for understanding natural communities. In: W. J. Resetarits, Jr. and J. Bernardo (eds.), Experimental Ecology: Issues and Perspectives. Oxford University Press, Oxford. pp. 133–151.
Scroggin, J. B. and W. B. Davis. 1956. Food habits of the Texas dwarf sirens. Herpetologica 12:231–237.
Szabo, A. R. 2002. Experimental tests of intercohort competition for food and cover in the tidepool sculpin (Oligocottus maculosus Girard). Can. J. Zool. 80:137–144.
Takimoto, G. 2003. Adaptive plasticity in ontogenetic niche shifts stabilizes consumer-resource dynamics. Am. Nat. 162:93–109.
Taylor, B. J., R. A. Estes, J. H. K. Pechmann and R. D. Semlitsch. 1988. Trophic relationships in a temporary pond: larval salamanders and their macroinvertebrate prey. Can. J. Zool. 68:2191–2198.
Van Buskirk, J. 1993. Population consequences of crowding in the dragonfly Aeshna juncea. Ecology 74:1950–1958.
Verrell, P. 1986. Wrestling in the red-spotted newt (Notophthalmus viridescens): resource value and contestant asymmetry determine contest duration and outcome. Anim. Behav. 34:398–402.
Warner, R. R. and P. L. Chesson. 1985. Coexistence mediated by recruitment fluctuations: a field guide to the storage effect. Am. Nat. 125:769–787.
Werner, E. E. 1986. Species interactions in freshwater fish communities. In: J. Diamond and T. E. Case (eds.), Community Ecology. Harper and Row, New York, pp. 344–358.
Werner, E. E. 1988. Size, scaling and the evolution of complex life cycles. In: B. Ebenman and L. Persson (eds.), Size-structured Populations: Ecology and Evolution. Springer-Verlag, Berlin, pp. 60–81.
Werner, E. E. 1994. Ontogenetic scaling of competitive interactions: size-dependent effects and responses in two anuran larvae. Ecology 75:197–213.
Werner, E. E. and J. F. Gilliam. 1984. The ontogenetic niche and species interactions in size-structured populations. Ann. Rev. Ecol. Syst. 15:393–425.
Wilbur, H. M. 1980. Complex life cycles. Ann. Rev. Ecol. Syst. 11:67–93.
Wilbur, H. M. 1984. Complex life cycles and community organization in amphibians. In: P. W. Price, C. N. Slobodchikoff, and W. S. Gaud (eds.), A New Ecology: Novel Approaches to Interactive Systems. Wiley, New York, pp. 195–224.
Wilbur, H. M. 1987. Regulation of structure in complex systems: experimental temporary pond communities. Ecology 68:1437–1452.
Wilbur, H. M. 1988. Interactions between growing predators and growing prey. In: B. Ebenman and L. Persson (eds.), Size-structured Populations: Ecology and Evolution. Springer-Verlag, Berlin, pp. 157–172.
Wilson, D. S. 1975. The adequacy of body size as a niche difference. Am. Nat. 109:769–784.
Wissinger, S. A. 1992. Niche overlap and the potential for competition and intraguild predation between size-structured populations. Ecology 73:1431–1444.
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Resetarits, W.J., Fauth, J.E. Diffuse competition and continuous niche shifts in size-structured populations of predatory salamanders. COMMUNITY ECOLOGY 6, 101–107 (2005). https://doi.org/10.1556/ComEc.6.2005.1.11
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DOI: https://doi.org/10.1556/ComEc.6.2005.1.11