Reproducing butterflies do not increase intake of antioxidants when they could benefit from them.

The significance of dietary antioxidants may be limited by the ability of animals to exploit them. However, past studies have focused on the effects of dietary antioxidants after 'antioxidant forced-feeding', and have overlooked spontaneous antioxidant intake. Here, we found that reproducing female Bicyclus anynana butterflies had higher antioxidant defences and enhanced fecundity when forced to consume antioxidants (polyphenols). Interestingly, these positive effects were not constant across the oviposition period. When given the choice between food resources with and without antioxidants, reproducing butterflies did not target antioxidants when they could have benefited the most from them. Moreover, they did not consume more antioxidants than non-reproducing butterflies. These results emphasize that, despite potential positive effects of dietary antioxidants, the ability of animals to exploit them is likely to restrict their ecological significance.