Additional file 1: Table S1. of Quantifying camouflage: how to predict detectability from appearance

Model terms in the simplified model of bandpass-based descriptive statistics. Prey X and Y screen coordinates are added with polynomial fits and an interaction. (DOC 140 kb

The number of each type of prey presentation made in sessions for all four experimental groups.

<p>The number of each type of prey presentation made in sessions for all four experimental groups.</p

The mean numbers (+/− SE) of mildly defended (circles) and moderately defended prey (squares) eaten in each session by birds in each of the experimental groups (N = 10 for all groups).

<p>The mean numbers (+/− SE) of mildly defended (circles) and moderately defended prey (squares) eaten in each session by birds in each of the experimental groups (N = 10 for all groups).</p

The proportion of eaten defended prey that were mildly defended in Sessions 3–8 and in the simultaneous choice session.

<p>Values over 0.5 show a preference for mildly over moderately defended prey. Birds marked with an asterisk (*) were labelled as discriminating birds.</p

The mean (+ SE) amount of quinine (mg) eaten per session in Sessions 3–8 in each of the experimental groups.

<p>Horizontal lines on the graph indicate the maximum amount of quinine available within a session for each group. The asterisk denotes a significantly lower ingestion of quinine in the Mild Defence group compared to the other groups. (N = 10 for all groups except the Non-Mimetic group where N = 9).</p

The mean (+ SE) number of mildly defended prey (light grey bars) and moderately defended prey (dark grey bars) eaten per session when birds had reached asymptote (sessions 3–8).

<p>In (a) data for all birds in all groups is included, and in (b) only data for the six discriminating birds in the Non-mimetic group is included (see text for details). Values that were significantly lower in the Non-Mimetic group compared to the Mild Defence and Moderate Defence group are marked with an asterisk. (N = 10 for all groups except the Non-Mimetic group where N = 9 in (a) and N = 6 in (b)).</p

Mortality of mildly and highly defended prey types.

<p>Proportion of mildly defended α and highly defended β prey consumed by predators in the four experimental treatments (Mildly defended prey α alone; Highly defended prey β alone; α and β both present but distinguishably coloured; α and β both present and perfect mimics) for three values of the availability of alternative prey <i>f</i>γ (a, b) <i>f</i>γ = 0.1, (c, d) <i>f</i>γ = 0.2, (e, f) <i>f</i>γ = 0.3, and for whether detoxification is (a, c, e) cost-free (κ = 0) or (b, d, f) costly (κ = 1).</p

Optimal foraging strategies when detoxification is not costly.

<p>Optimal foraging strategy for predators, shown as which prey types are rejected as a function of energy reserves <i>R</i> and toxin burden <i>D</i> for the four treatments: (a) mildly defended prey, α alone; (b) highly defended prey, β alone; (c) α and β both present and visually distinguishable; (d) α and β both present and perfect mimics. Here, there is no detoxification cost (κ = 0) and alternative prey are at intermediate availability (γ = 0.2). The shaded areas show the states where: the predators reject all prey including alternative prey (black); reject only the mildly defended prey (pale grey); reject only the highly defended prey (intermediate grey) reject both defended prey (dark grey). In the white areas, all prey are accepted.</p

Parameters of the predator and the values explored.

<p>Parameters of the predator and the values explored.</p

Impact of alternative prey on predator strategy and -state when defended prey are non-mimetic.

<p>Effect of availability of alternative prey (<i>f</i>γ) on predator strategy (a, c, e) and stationary distribution of predator state (b, d, f) in the non-mimetic treatment. Results are shown for three values of availability of alternative prey (a, b) γ = 0.1, (c, d) γ = 0.2, (e, f) γ = 0.3. The shaded areas show the states where: the predators reject all prey including alternative prey (black); reject only the mildly defended prey (pale grey); reject only the highly defended prey (intermediate grey) reject both defended prey (dark grey) (a, c, e). In the white areas, all prey are accepted. Distribution of predator states are shown from high (white) to zero (black) (b, d, f).</p