Figure 1.
The effects of predator cue and mud crab removal rate on (a) mud crab per capita foraging rate and (b) the number of juvenile oysters consumed during Experiment I.
There was no effect of predator cue on per capita mud crab foraging rates, but we show the predator cue treatments separately for comparison with panel b. Closed squares indicate catfish cue is present at high tide; open circles indicate catfish cue is absent at high tide. Symbols represent means(±SE).
Table 1.
Results of nested linear mixed-effect models for Experiment I.
Figure 2.
Direct and indirect predator effects in Experiment I.
(a) The strength of non-consumptive (NCE) and consumptive (CE) effects on mud crab foraging rates in Experiment I. A negative effect size indicates that crab foraging rates were enhanced by predator cues (NCE) or crab removal (CE). Neither NCEs nor CEs varied by culling treatment (high cull or low cull). Bars represent means(±SE). (b) The strength of trait-mediated indirect interactions (TMII), density-mediated indirect interactions (DMII) and total indirect predator interactions (TII) on oyster abundance in Experiment I. A positive effect size indicates that oyster abundance was enhanced by predator cues (TMII), culling (DMII), or the combination of high culling and predator cues (TII). DMIIs did not vary by culling treatment (high cull or low cull). Bars represent means(±SE).
Figure 3.
The effects of predator cue and mud crab density on (a) mud crab per capita foraging rate and (b) the number of juvenile oysters consumed during Experiment II.
Closed squares indicate predatory fish cue is present at every high tide; gray squares indicate predator cue is present at every other night-time high tide; open circles indicate predator cue is absent at high tide. Symbols represent means(±SE). For reference, the average mud crab density in Experiment 1 was as follows: high culling = 7.3; low culling = 9.0; no culling = 10.0.
Table 2.
Results of nested linear mixed-effect models for Experiment II.