<p>Lines connect all trials of the same bird when it was in the small gizzard group (open dots) and in the large gizzard group (solid dots). Intake of <i>Dosinia</i> was higher for birds with large gizzards, whereas intake of <i>Loripes</i> was not affected by gizzard size (model 2.1 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0136144#pone.0136144.s006" target="_blank">S1 Table</a>). <i>Loripes</i> intake rate was generally lower than <i>Dosinia</i> intake rate. These results confirm that intake of <i>Dosinia</i> is limited by a digestive constraint, whereas intake of <i>Loripes</i> is limited more stringently, presumably by its toxic load, and independent of gizzard mass.</p
