Feeding Ecology of Stream-Dwelling Pacific Giant Salamander Larvae (Dicamptodon tenebrosus)

Parker, Michael S.

doi:10.2307/1447187

Cited by 63 publications

(52 citation statements)

References 51 publications

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“…This finding is consistent with previous observations that salamander diets are dominated by benthic aquatic invertebrates (Parker 1994). Further, given the high biomass of predatory and largely benthic feeding Pacific giant salamanders that we found in Fox Creek, occurring at twice the density of 1þ steelhead (0.52 salamanders/m 2 vs. 0.26 steelhead/m 2 ), we predicted that benthic invertebrate biomass would be depressed in their presence.…”

Section: Discussionsupporting

confidence: 92%

“…We also predicted that YOY steelhead would have reduced growth in the presence of large 1þ steelhead and salamanders, but did not detect any effect of either predator on their growth. Despite considerable diet overlap between salamanders and 1þ steelhead (Parker 1994, Munshaw et al 2013, the presence of salamanders had no detectable effect on the growth of 1þ steelhead, regardless of the availability of terrestrial prey. Limited isotope samples collected in conjunction with the experiment suggest that steelhead relied on terrestrial prey to a much greater degree during the summer than large (.100 mm SVL) salamanders (Appendix B).…”

Section: Discussionmentioning

confidence: 91%

“…Alternatively, if predatory steelhead preferentially exploit terrestrial prey resulting in a positive effect of resource subsidies on in situ consumers, we predicted that experimental reductions in terrestrial prey in-fall would necessitate a shift in predation by trout towards a more aquatic prey base, depressing aquatic herbivores and amplifying trophic cascades relative to treatments where terrestrial prey were available. Patterns of top-down regulation by salamanders, which feed primarily on benthic aquatic prey (Parker 1994), were not expected to Fig. 1.…”

Section: Introductionmentioning

confidence: 86%

“…2D, Table 2). The majority (65% of biomass) of aquatic invertebrates sampled from benthic rocks in Fox Creek were comprised of relatively predator-invulnerable taxa such as armored and case building caddisflies (Order Trichoptera), which are rarely found in the diets of steelhead and salamanders (Parker 1994, Wootton et al 1996. When the biomass of vulnerable and invulnerable (armored) taxa were analyzed separately there was support for top-down control v www.esajournals.org of vulnerable herbivore biomass in experimental units with steelhead (À11.3 6 5.4 mg DMÁm À2 , Fig.…”

Section: Food Web Responsesmentioning

confidence: 99%

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Dependence of stream predators on terrestrial prey fluxes: food web responses to subsidized predation

et al. 2013

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Abstract. Resource subsidies in the form of energy, materials, and organisms can support the productivity of recipient ecosystems. When subsidies increase the abundance of top predators, theory predicts that top-down interactions will be strengthened. However, the degree to which subsidies intensify predation should be constrained by the strength of interactions between predators and their prey. To test the potential for subsidies to drive strong top-down control by two stream predators, steelhead (Oncorhynchus mykiss) and Pacific giant salamander (Dicamptodon tenebrosus) we reduced terrestrial prey and manipulated the presence of predators in 32 stream reaches. Prey subsidies supported elevated growth of predatory steelhead in our study system and in the absence of allochthonous prey steelhead experienced a 187% reduction in growth. Despite the high biomass of subsidized predators, there was little support for strong top-down control of herbivore biomass, or a trophic cascade as measured by changes in AFDM and chlorophyll-a. This result was consistent across subsidy treatments, suggesting that predatory steelhead are unable to increase exploitation of aquatic prey in the absence of terrestrial prey subsidies. The potential for top-down control was apparently limited by the fact that most (82%) herbivores in our study system were armored and relatively invulnerable to predation. These results demonstrate the potential importance of behavioral and morphological adaptations that can temper predator prey interactions in highly subsidized ecosystems.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 86%

Section: Food Web Responsesmentioning

confidence: 99%

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Dependence of stream predators on terrestrial prey fluxes: food web responses to subsidized predation

et al. 2013

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“…La depredación tamaño-selectiva es un rasgo común de las interacciones depredador-presa, para una variedad de ambientes acuáticos (Werner & Hall 1974;Newman & Waters 1984;Parker 1994). Basados en esta premisa, se ha determinado la ausencia de evidencias que demuestren que el número de presas, así como el tamaño de éstas, esté relacionado con la longitud corporal en P. thaul.…”

Section: Materiales Y Metodosunclassified

Habitos Alimentarios De Pleurodema Thaul (Anura, Leptodactylidae), en Concepcion, Chile

Díaz-Páez

Ortíz

2003

Gayana (Concepc.)

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RESUMENSe analizó la dieta de una población del sapito de cuatro ojos (Pleurodema thaul) de la localidad de Hualpén (Talcahuano, Chile). El estudio se realiza durante los períodos reproductivos (junio-diciembre) que comprenden los años 2000 y 2001. Estos anuros destinan una menor importancia al consumo de presas durante la época reproductiva, por lo que presentan una baja frecuencia de ocurrencia (50,63%). La dieta de P. thaul está compuesta fundamentalmente de artrópodos (IRI = 0,92), con un consumo de menor importancia de vegetales (IRI = 0,035). Se determinó una alta diversidad de ítemes de presa (37 taxa). Los ítemes alimentarios dípteros y arácnidos son los más comunes. No se detectan relaciones entre el tamaño de las presas y el tamaño de los anuros.PALABRAS CLAVES: Dieta, Anfibia, Leptodactylidae, Chile. ABSTRACTWe examined the diet for four eyes toad (Pleurodema thaul) in Hualpén (Talcahuano, Chile). The study was carried out during the breeding season (June -December) in 2000 and 2001. These anurans consume fewer preys during the breeding season, and they present a low occurrence frequency (50.63%). The results show the P. thaul diet include for arthropods (IRI = 0.92), with a lower consumption of vegetables (IRI = 0.035). We determined a high diversity of prey, with 37 taxa of invertebrates. The alimentary items dipteral and arachnids are the most common. No relationships occurred between the size of the preys and the size of the anurans.

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Temperate Rain Forest

Chapman

Bolen

2015

Ecology of North America

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Feeding Ecology of Stream-Dwelling Pacific Giant Salamander Larvae (Dicamptodon tenebrosus)

Cited by 63 publications

References 51 publications

Dependence of stream predators on terrestrial prey fluxes: food web responses to subsidized predation

Dependence of stream predators on terrestrial prey fluxes: food web responses to subsidized predation

Habitos Alimentarios De Pleurodema Thaul (Anura, Leptodactylidae), en Concepcion, Chile

Temperate Rain Forest

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