Predicted relative preference in choices between a standard option and alternatives with different sugar solutions.

<p>The vertical dashed line passes through the sugar concentration of the standard option in each panel. Perfect discrimination performance would look like a step function at zero before and at one after the sugar concentration of the standard. The closer a curve lies to the vertical dashed line, the better the predicted discrimination performance. (<b>A</b>) Standard option with 10% w/w concentration. (<b>B</b>) Standard option with 25% w/w concentration. (<b>C</b>) Standard option with 50% w/w concentration. In each panel different lines (see legend in A) give the predicted preferences for the alternative option of different nectar-feeding species: <i>G.s. – Glossophaga soricina</i>, this study; <i>G.c. – Glossophaga commissarisi</i>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074144#pone.0074144-Nachev1" target="_blank">[23]</a>; Troch. – different hummingbird (Trochilidae) species, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074144#pone.0074144-Hainsworth2" target="_blank">[43]</a>; <i>B.i. – Bombus impatiens</i>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074144#pone.0074144-Nachev2" target="_blank">[24]</a>; <i>A.m.l. – Apis mellifera ligustica</i>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074144#pone.0074144-Sanderson1" target="_blank">[44]</a>. The values of the exponent <i>β</i> are given in the legend. Note that in A, in the concentration range 0–20% the insects have a higher probability of choosing the energetically less profitable option (i.e. choosing 5% instead of 10% or choosing 10% instead of 15%) than the vertebrates. However, in C the insects are much better at avoiding the options with less than 50% sugar.