Influences of Predatory Fish on the Drift Dispersal and Local Density of Stream Insects

Abstract

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Impacts of an introduced predatory fish on mayfly grazing in New Zealand streams

“…Predators can restrict prey movement, microhabitat selection, positioning, and the ability of prey to harvest resources, causing important alterations in prey diet, growth, fecundity, and drift (e.g. Macchiusi and Baker 1992;Peckarsky et al 1993;Cowan and Peckarsky 1994;Forrester 1994). However, most of these studies have been confined to comparisons of pairs of streams (but see Flecker 1992;Douglas et al 1994) or have been conducted in artificial laboratory settings.…”

Population-level consequences of heterospecific density-dependent movements in predator–prey systems

“…However, our robustness analysis shows that the approximation error in our model is negligible if the strength of the density dependent emigration functions corresponds to that typically observed in empirical studies. Stronger density dependence, which would require higher-order approximation, was observed in only one case (Forrester 1994). This suggests that our deterministic approximation is valid for modelling the spatial density-dependent processes that are captured at scales at which the processes are typically studied.…”

Structural Complexity of Artificial Habitat and the Feeding Success of Predatory Dragonfly and Damselfly

“…The later could be because the predation behavior of dragonfly does not appear to be selective to the real prey only, but its prey may also include the other smaller species of Odonata (Watson et al, 1991), such as Damselflies. On the other hand, all the Dragonfly nymphs are lurkers (Macan, 1973), therefore, the sit and wait successes of predators in complex structure of habitats may be primary due to prey are mobile (Forrester, 1994).…”