20 Result(s)
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Barbara L. Peckarsky
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Article
Shifts in isotopic signatures of animals with complex life-cycles can complicate conclusions on cross-boundary trophic links
Stable isotopes (13C and 15N) are widely applied in studies of trophic links. We used this method to investigate the contribution of aquatic and terrestrial prey to the diet of riparian predatory arthropods in tw...
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Costs of predator-induced phenotypic plasticity: a graphical model for predicting the contribution of nonconsumptive and consumptive effects of predators on prey
Defensive modifications in prey traits that reduce predation risk can also have negative effects on prey fitness. Such nonconsumptive effects (NCEs) of predators are common, often quite strong, and can even do...
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Article
Large-scale manipulation of mayfly recruitment affects population size
Recruitment establishes the initial size of populations and may influence subsequent population dynamics. Although strong inference can be made from empirical relationships between recruitment and population s...
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Does the morphology of beaver ponds alter downstream ecosystems?
Differences among lake morphologies often explain variation in characteristics of lentic ecosystems. Although beaver ponds also vary in morphology, previous studies have not examined the effects of such variat...
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Predator effects on prey population dynamics in open systems
Animal population dynamics in open systems are affected not only by agents of mortality and the influence of species interactions on behavior and life histories, but also by dispersal and recruitment. We used ...
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A comparative study of the costs of alternative mayfly oviposition behaviors
Oviposition behavior of insects has associated fitness costs related to the probability that females survive to oviposit. During summer 2003, we observed the oviposition behavior and compared the mortality rat...
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Article
Selective oviposition of the mayfly Baetis bicaudatus
Selective oviposition can have important consequences for recruitment limitation and population dynamics of organisms with complex life cycles. Temporal and spatial variation in oviposition may be driven by en...
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Article
Effects of pulsed and pressed disturbances on the benthic invertebrate community following a coal spill in a small stream in northeastern USA
In September 1999, a coal-carrying train derailed and spilled 180,000–270,000 kg of coal into the Cayuga Inlet near Ithaca, New York. This study determined the immediate effects of the coal spill and the clean...
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Article
How do grazers affect periphyton heterogeneity in streams?
The effects of grazing by stream invertebrates on algal biomass and spatial heterogeneity were tested experimentally in flow-through microcosms with natural substrates (rocks). One experiment tested the effect...
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Article
Developmental responses to predation risk in morphologically defended mayflies
Densities and species composition of predators could affect morphological defences, larval development and the timing of emergence of their prey. To address this issue we studied the morphology and life histor...
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Article
Swarming and mating behavior of a mayfly Baetis bicaudatus suggest stabilizing selection for male body size
Large size often confers a fitness advantage to female insects because fecundity increases with body size. However, the fitness benefits of large size for male insects are less clear. We investigated the mati...
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Article
Hydrologic and behavioral constraints on oviposition of stream insects: implications for adult dispersal
The supply of recruits plays an important role in plant and animal population dynamics, and may be governed by environmental and behavioral constraints on animals. Mated females of the mayfly genus Baetis alight...
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Article
Rapid size-specific changes in the drift of Baetis bicaudatus (Ephemeroptera) caused by alterations in fish odour concentration
Chemical cues from fish can alter the behaviour of stream invertebrates in experimental tanks but their effect in natural streams has received little attention. By adding brook trout (Salvelinus fontinalis) odou...
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Article
Effects of size at metamorphosis on stonefly fecundity, longevity, and reproductive success
Many organisms with complex life cycles show considerable variation in size and timing at metamorphosis. Adult males of Megarcyssignata (Plecoptera: Perlodidae) are significantly smaller than females and emerge ...
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Article
Fitness and community consequences of avoiding multiple predators
We investigated the fitness and community consequences of behavioural interactions with multiple predators in a four-trophic-level system. We conducted an experiment in oval flow-through artificial-stream tan...
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Article
The effect of mermithid parasitism on predation of nymphal Baetis bicaudatus (Ephemeroptera) by invertebrates
We investigated how infection by the mermithid nematode Gasteromermis sp. affected predation on its nymphal mayfly host, Baetisbicaudatus, by two invertebrate predators – the stonefly nymphs of Kogotusmodestus an...
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Article
Consequences of larval intraspecific competition to stonefly growth and fecundity
We conducted experiments in replicated circular streams to measure the effect of intraspecific larval density on growth rates, size at emergence, timing of emergence, and fecundity of two species of predatory ...
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Article
Mechanisms of intra-and interspecific interference between larval stoneflies
Behavior of focal individuals of two potentially competing sympatric stonefly species, Megarcys signata and Kogotus modestus (Perlodidae), was videotaped in flow-through plexiglass arenas placed in the East River...
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Article
Stonefly nymphs use hydrodynamic cues to discriminate between prey
Playback experiments conducted in a Rocky Mountain, USA, stream determined whether predatory stonefly nymphs (Kogotus modestus; Plecoptera: PerlodiMae) used hydrodynamic cues to discriminate prey species from non...
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Chapter
Use of Behavioral Experiments to Test Ecological Theory in Streams
Direct behavioral observation of stream invertebrates was practiced extensively by aquatic entomologists in the early part of this century. Early descriptions of stream insect behavior were usually qualitative...
